Category Archives: Tech

Modifications to my Gumotex Seawave

Seawave main page

yaldingGrappling to get the boat out of the muddy Medway river at Yalding the other day put a light scrape on the hull. It reminded me that, along with the PRVs, another winter job was to fit a protective strake under the bow where most scraping occurs. Better to get the protection in early while the boat is newish.
Upstream the Medway had been high and even had a noticeable current. Two-up we were flying along at a good 5mph+ at times. Some of the chutes I was looking forward to were closed even though they look merely ‘sporty’, but then weir by weir, lock by lock the level started dropping so that never before seen eddies, whorls and rocks appeared. The super-sporty chute at Sluice Weir Lock was high and dry (clambering out onto the nearby jetty was a real effort) and by the time we got to Yalding near the end there was a 6-foot drop with muddy banks to either side on which you sank up to your knees.
medclosedSoon covered in muck, we managed to clamber out over the mossy weir wall and haul the boat up. Had I been less cavalier about my preparations I’d have read what was going on right here. Looks like the Medway chutes will be out of action till March (right). Knowing that would have saved half the next morning hosing myself and all the gear down.
strakerBack to the strake. A 70 x 15cm Hypalon off-cut (close enough to Nitrilon) was 14 quid on ebay and once trimmed left enough for another strake or two. I had some Polymarine two-part adhesive (below) and glued the strip to the boat’s curved form with the floor inflated, ami-polyeven if that meant working the roller to press it all together was less effective. I then slathered some Seam Seal around the nose of the strake to protect it from unpeeling (less runny Aquaseal would have been better but a Seam Seal tube was open. More on glues here).
footerWhile the boat was filling the hallway and causing a hazard to domestic navigation I also bodged up a better system for the all-important footrest. A bit of inner tube now counter-tensions the footrest from the bow to keep it in position. It means the thing is now fully adjustable across a wide range ofsw-cantilastic positions, can easily be fine tuned from the water, removes in seconds for boat cleaning/drying and needed no extra fittings glued to the boat. Once great thing about the Seawave is the multitude of attachment points on the floor and sides.
While on the river my aged Mk1 Alpacka U-seat base went flat, split right in the U. This seat is part of a lighter and comfier system I brought over from my Amigo – an improvement on the one-piece Seawave seats. It’s currently unfixed to the boat and the thin nylon must have ripped while yanking it into position on the river after getting back in. Again, I’m trying to avoid gluing extra D-rings to the hull – they’d limit seat base adjustment options anyway.
sw12Better then to attach the seat base to the base of the backrest (right) with a couple of zip ties. The whole backrest/seat base can then slide forward and back off the backrest side straps and it all unclips from the boat in less than 3.7 seconds. alpacka-seatI glued up the punctured U-seat but it won’t last, so I’ve ordered MkII Alpacka seats (left) from Packrafting Store: €70 delivered for a pair. From Alpacka US the seats cost $25 but their auto-calculated international postage is nuts, let alone tax and VAT issues. These seats have the U filled in like a webbed foot: stronger and less floppy for just ~12g extra weight.
Since then I decided not to fit the seat base to the backrest, but simply attach it to the floor between a similar the same adjustable strap and elastic tension system used on the footrest. So far so good. Will add a photo next time the boat’s out.
SOTstrapI’ve also ditched my old my SoT thigh straps (right). Nanfistrapsicely padded and effective though they were, the brass spring connectors and padding made them feel heavy and bulky at ~720g.
Instead I got some non-padded Anfibio packrafting straps from the Packrafting Store (without their biners or D-ring patches). With my biners they come in at 270g. The delta-straps dangling off the sides are a clever idea, designed to give a fpy165more direct pull when rolling a packraft for example. Can’t see myself doing that in any of my boats, but if there happens to be a handy attachment point on the Seawave’s hull I may give them a go (normally you’d have to glue on the D-ring patches supplied). Whether you’re rolling or just paddling, in rough water the more direct connection with the boat the better. I’m a big fan of these light but effective straps now. No need for paddling

Fitting 4.8 psi PRVs on a Gumotex Seawave

Seawave main page
General article covering PRVs

Updated Summer 2020
yalding

My old Gumotex Seawave was a well spec’d IK for my sort of inshore paddling and occasional touring, especially as it was factory rated to run at a higher-than-usual 0.25bar or 3.6psi (normal is 0.2 on Helios, Palava, 410C, etc). That means greater rigidity which adds up to less longitudinal sag caused by paddler weight (who, me?!) and of course a better glide. My previous Amigo and Incept both ran an even higher 0.3 bar, and it’s said that this Gumotex can also be pushed to that sort of pressure on the side tubes without risking damage. Factory hull pressures are set on the conservative side, perhaps to limit warranty claims.
Like all the Gumboats I’ve owned, the more vulnerable I-beam floor chamber has a factory-fitted PRV, presumably set at 0.25bar/3.6psi (confirmed below). PRVs are important here as if an IK gets hot (typically out of the water on a sunny day) internal air pressure can increase to the point where seams can rupture or the boat can blow. If separation happens to an internal I-beam in the floor it will balloon up and becomes a very difficult repair. I would not meddle with the factory-set PRV on an i-beam floor.
As we all now know, the way round an I-beam floor’s limitations is drop-stitch technology – effectively zillions on ‘i-beams’ spreading the load over the entire area which enables much higher pressures.

PRV-PalaverIn a discussion with a French Gumtexer, he suggested that Gumotex use the same orange dot  0.243 PRVs in all their boats, irrespective of the stated official rating which is either ‘0.2’ like most or ‘0.25’ like the Seawave. He sent me a photo of his 2016 Palava floor PRV (right) – orangey-pink, same as my Seawave and classified by Ceredi as 0.243.
Officially the Palava is a ‘normal pressure’ 0.2 bar canoe. Upshot? Your Gumboat’s floor may be rated at higher pressure than you think or is officially stated – and you’d assume the tubed sides can handle at least as much pressure. Then again, in the table below, Ceredi state the orange PRV  will open between 0.21 and 0.243 so perhaps we all just need to calm down a bit.

Guatemala, Fuego volcano, Strombolian eruption

PRVs use springs set to purge air before it reaches structure-damaging levels. Then again, my Amigo had no PRVs at all so you assume Grabner were confident their floor construction was solid enough to handle occasional neglect. But I’ve been caught out before and always try to ensure a boat remains in the cooling water when moored up on hot days – even getting up to throw on a cooling splash as the sides tighten up like a drum.

cerediprv

Like most IKs with single side tubes, my Seawave had no PRVs in the side tubes as the tubular profile can handle higher pressures better than a flat, ‘lilo-like’ floor. However, if you’re planning to run them over-pressure as I am suggesting, that could be risky. The answer: fit PRVs in the two side chambers – just like my old Incept. That way you can safely leave you IK out of the water in the tropics, go and hike up a volcano (which might be described as ‘the planet’s PRVs’) knowing that all three chambers on your IK will harmlessly purge any excess pressure. Sure, when it all cools again in the water the boat may be saggy, but better a quick top up with your K-Pump than pulling bits of shredded Nitrilon out of the palm trees. Ideally I was looking for a PRV set at a reasonable 30% over the factory figure of 0.25 bar – i.e.: something around 0.33 bar or 4.8psi.

prvcolours
I admit that the colours look pretty close but it’s pinky-orange for the OE floor and red for my 0.33s

Well-known IK valve-makers Leafield and Halkey didn’t make anything matching my needs (or don’t sell to individuals). The Seawave’s valves are stamped ‘Ceredi Italy’ and once I managed to track them down online, I saw the same Ceredi 6600 PRV series came in options including Red 4.78 psi or 0.33 bar, (left and below). In the UK they were a special order via IBS and cost £35 a pair posted.


As you can read from Adam’s comment below, there is – or more probably was – a super valve which combines both inflation and pressure-release duties which means you simply replace the stock inflation-only valve. No need for extra holes to be cut. His link no longer works but I tracked it down to here; the Bravo Super Valve – that’s Bravo as in the cheap Italian branded pumps we all know and love. But there is no mention of a super valve on their valve page, nor is it in their catalog. Wet Works in the UK were selling 4.35psi super valves for £15. I ordered two; nothing happened soI take it they never actually had them.


Fitting the PRVs

grabtool

Tools and time needed
• Gumotex inflation valve removing tool (fits Ceredi PRVs also). Right;  £12 on ebay

• Narrow-bladed knife or scalpel
• Water pump/lock channel pliers
• 30 mins

Short version
• Choose your spot, mark and then cut a 37mm hole in each side chamber. The Ceredi-suggested 35mm was not enough. Or fit a Bravo Super valve – see above
• Remove the side chamber’s inflation valve with the tool
• Squeeze the PRV’s threaded back collar through the bigger inflation valve hole, shuffle it over to the 37mm hole and screw on the external part of the PRV by hand
• Reassemble the inflation valve and tighten both valves with the tool
• Fit push-on caps to the PRVs
• Pump up and check for leaks. Maybe retighten some valves with the tool

prvvs.jpg
Hadron

Long version
I chose to fit the PRVs close to the inflation valves and at about the same level. There are mysterious markings on the inside of the Seawave to aid symmetrical positioning (Pic 2, below). I used a narrow-bladed knife and of course took care to gather up the hull skin so I wouldn’t inadvertently puncture the other side of the side tube. I assumed the 35mm hole would be big enough to take the back nut. When it wasn’t I was a bit flummoxed. Now I had a gaping hole in my boat, but no way of getting the back of the PRV inside the boat without performing a Caesarian on my Seawave. Luckily two brain cells dropped into my Hadron Collider and it occurred to me that once removed, the nearby main inflation valve’s hole might be bigger. And it was – just.
One stock valve was extremely hard to undo. I wondered if it had mistakenly been glued in or that the plastic valve removal tool would snap. When the other side undid with less effort I knew it had to be possible.

Another problem is that the internal collar or nut is only 10cm deep (pic 4, below) and so was hard to grab through the hull fabric. Until I realised this, I was grabbing the inside part of the outer valve body which screws through the collar from the outside. Trying to ‘unscrew’ the valve body from itself is like trying to pull you head off –  eventually  the valve tool would break. Another ‘Higgs boson’ moment came over me and I realised that by chance the two valve holes in the boat were close enough for me to get some water-pump pliers in there, grab the back collar and finish the job (pic 6, below). After that, no more problems.
One thing I noticed while doing all this was the unseen protective patch on the inside of the hull opposite the inflation valves to limit wear and rubbing between valve body and hull when the boat’s delated. Nice touch, Gumotex ;-)

I did all the valves up as hard as possible with tool and hand, and in four more years had no problems. On a hot day in the sun I can hear the high-pressure side PRVs hissing away. The gallery below shows the job in chronological order.

prvrv02
The bits you need
prvrv05
Incision, but the right-sized 37-mm hole is too small to pass through the ’35mm’ PRV back collar
prvrv06
37mm hole is better, but still not wide enough to pass through the inside ‘retaining nut’ of PRV assembly
prvrv04
You need to remove the main inflation valve  (it’s hard to grab the inside part by hand). Then the PRV back nut just squeezes through main valve hole and can be shuffled along towards the new hole
prvrv11
Holding the PRV back nut in place to tighten is hard by hand. So pass pliers through the main valve hole…
prvrv12
… to clamp onto the back of the PRV assembly. This is why it helps to cut the PRV hole close to the main valve
prvrv09
PRV done. Now replace main valve
prvrv07
Clamp them all up
prvrv14
PRVs as far as the eye can see

Now it’ll be good know that should I doze off as the tide ebbs away, I won’t be rudely woken by an exploding boat. Another side benefit of doing this is that you’ll never need to use a manometer (pressure gauge) again. You simply pump up all three chambers until they hiss and you know they are at full pressure.

smoko

Tested: Anfibio Packsuit (drysuit review)

Anfibiodry-6Even in summer the benefits of a drysuit for northern UK paddling are like wearing overalls to get stuck into a messy job; you know you’re covered. You can wade in as deep as you like and take all the splash that’s going without risking getting chilled should your underclothes get soaked when a waist or limb seal leaks. And for me, nervous of the deep and often paddling alone in the northwest (even if it’s rarely more than a mile from shore), it’s an added layer of security.
hyperdryMy old Crewsaver Hyperpro drysuit (left) cost only £180 and did the job amazingly well. But even at only 2kg, it was heavy enough to need internal braces and was often too hot and sweaty for fast paddling, even in a northwest Highlands summer. In fact I wonder if it was more of a jet ski-ing suit not suited to paddling? When it comes to exposure, should you fall in, being wet from trapped sweat is nearly as bad as being wet from seawater. Once pressed against your body by water pressure, I’m told the actual benefits of a drysuit in slowing down hypothermia Anfibiodry-1are only measured in a few extra minutes. To be agile enough for paddling, drysuits are not immersion or survival suits (right) made to snuggly bob around for hours until the RNLI find you. In such a scenario it’s the fleece underneath a gulregular paddling drysuit that can make a difference and I have a Gul one-piece (left) for  those chilly days. At anything above single-digit temps it’s just too warm, but if anyone remembers romper suits from their toddling days, they know how comfy it is to wear a onesie over their nappies. They go for about £25 (try amazon); well worth it in my opinion and handy on a winter’s motorbike ride too.

Whatever clever membrane fabric the Crewsaver used, it was better at keeping water out than venting my steam. And anyway, I’ve never experienced the magic of breathable membranes which I believe work under a much narrower set of parameters (temperature gradients, fabric saturation and cleanliness) than we imagine, even if they’re surely better than wrapped in bin bags and duct tape.

troposBefore the Hyperpro I briefly owned a nice and light Kokatat Tropos dry suit (left) which I sold in haste and which closely resembled this Packsuit. Kokatat don’t use the Tropos fabric anymore so maybe it’s just as well I flogged it. The closest thing they now sell is the Hydrus fabric 3L for around £680 in the UK.

As often happens with gear for a given activity, it takes a bit of trial and error to find what actually fits your needs, rather than the full-on expedition stuff you think you need – or what’s going cheap at the time in your size. I’d often wondered what exactly a semi-dry suit was – a half-arsed fabric that sort of keeps water out? Sven at Packrafting Store explained: it’s a drysuit with a comfier neoprene rather than latex neck seal. Latex (as on my Hyperpro) seals very well but worn all day it gets uncomfortable. Apart from some sad celebs and Tory politicians, no one likes being auto-asphyxiated for fun. I recall Anfibiodry-3reading some guys who paddled South Georgia island in the South Atlantic fitting ‘venting hoops’ into the latex neck seals of their top-of the range Kokatat drysuits during less stormy episodes to stop them choking or boiling over. Unless you expect to be frequently immersed or hosed over in storm- or whitewater conditions, a clingy latex neck seal is less useful than on the wrists. Meanwhile for the feet Sven confirmed what I felt: integral latex socks are the way to go; heavier than taped fabric versions  but much easier to repair, more robust for walking plus reliable and better than ankle seals in keeping feet warm. Full latex socks, latex wrists and neoprene at the neck; the best all round combination of drysuit sealage for my sort of paddling.

crewsaver-hyperdryThe Crewsaver had a horizontal back zip, the Tropos was front diagonal while the Anfibio is front horizontal. The back zip may look neat (right) but when tired or cold I found the articulation required to unzip myself was quite an effort. It does mean you can open it on the water to vent off while guarding against frontal splash, but it would be hard to zip up in a hurry. Anfibiodry-8Front diagonal doesn’t seal so well with spray skirts they say (not an issue with me with IK&Ps) and so it’s hard to find fault with the front horizontal format.

I found the Packsuit easy to get into, light enough not to sag and the zip easy to work and ascertain that you’ve sealed it properly. The Anfibio suit uses a light, plastic TiZip Masterseal dry zip (left and below) that’s lighter and easier to slide than the usual chunky brass YKKs I’m used to. Wax or silicon spray is all the TiZip needs, as with YKKs.
303Anfibio’s Packsuit can weigh as little as 800g in smaller sizes. My XL version was custom tailored and with the latex sock and the relief zip options weighs 1332g and rolls up to about half the volume of my Hyperpro. Weight is saved with no cuffs covering the latex parts which are said to be vulnerable to UV. A regular dose of 303 (right) should see to that. There are also no pockets or other features, just what you need to keep you dry.

Anfibiodry-5Best of all, on our four-day paddle around the Slate Islands I found the Anfibio Packsuit unobtrusive to wear. Unlike with previous drysuits, I rarely felt the need to peel off at the slightest stop and the relief zip was a no brainer, enabling on-water ‘defuelling’, just like a B52 on a long-range mission Wearing just a shirt and runner’s leggings, I never felt hot on the water Anfibiodry-4nor got chilled, and during a downpour on land one evening was happy to wear it right up to the point we scurried for our tents.

Sorry to say I forgot to do an immersion test but will get round to that. I did find that the stretching made the inside coating peel off the neoprene neck seal – see picture below – but don’t know what this coating is actually for. It’s certainly not waterproofing so doesn’t really matter. Other than that, no issues.
packrafting_store_logoI received the Packsuit in return for editorial work on the Packrafting Store website. It costs from €399 with tax and in my custom spec would have cost €530.

Another good lightweight drysuit I’m told is a Stohlquist EZ for $500.

P1040386

Tim Evans’ superlight cuben fibre folding kayaks

Tim-Evans-Cuben-Kayak02Tim Evans from Vancouver got in touch via the busy IK&P press office to tell us about his new 10lb (4.5kg) IK. Made from a super strong, light but expensive wonder fabric called Cuben Fibre which regularly features in discussions at Backpacking Light, the 14-foot IK was made to fill the gap between packrafts like his Yak and super light Supai, and a regular, faster IK.
Having worked on his own gear, Tim’s design is based on one of Tom Yost’s well-known MYO packboat templates which I’ve come across in my online travels. He writes:
Tim-Evans-Cuben-Kayak04Commercial inflatable kayaks are much faster [than packrafts], but are too heavy. I don’t want to carry more then 30lbs, which has to include the boat, paddling gear, camping gear and food. What I really wanted was a fast IK that weighed 10 pounds or less. It didn’t exist (as far as I could tell), so I made one. Here’s a video showing the boat.

Tim-Evans-Cuben-Kayak08It’s 14 feet long and weighs 10lbs. As you can see in the video, it’s a lot faster than a packraft. The key to the light weight was Tom Yost’s very simple design concept, modified a bit, and married with the lightest available materials. The hull skin material is very strong, but abrasion resistance is it’s weakness. This can be a problem with barnacle encrusted rocks (as I have found) when paddling in the ocean, but in the lakes I made the boat for, there should be few if any sources of abrasion. The skin of the boat weights about 1.6 lbs, interestingly about the same weight as the Supai.
homemade-pfdI made the kayak to redo a trip I did last summer in the Supai. I made an inflatable PFD for that trip (left), which I have tested in the water and it supports me quite well. Since I take several inflatable cushions with me anyway, the extra weight for the PFD is just 260 grams for the shell.

[Regarding the poor abrasion resistance] I think it comes down to calculated risk. I always have some kind of backup plan if the worst case happens. While the kayak skin is a bit delicate, I will take various repair tapes and Aquaseal with me. And since I made the boat myself, I should be able to repair it in the field if I have to.
Tim-Evans-Cuben-Kayak09As for stability, the boat is no worse than any other narrowish kayak. But I have one final ace up my sleeve. I will be taking my Supai as a back up boat (right)! At 1.5 lbs, why not. Since I have already done the trip in the Supai, in case the kayak became so damaged as to be unrepairable (which is quite unlikely), Tim-Evans-Supai01I just do the rest of the trip as I did last time. I will stay within a swim of the shoreline of the lakes and the water is not that cold, so a dunking should not be life-threatening. Sure, there are always unforeseeable hazards, but I think life is too short to play it too safe.

Tim’s summer 2014 pics with the kayak on the Powell Forest Canoe Trail
Tim’s 17-foot version built in 2015
cubenmaker.com

tim9

Anfibio Buoy Boy inflatable packrafting jacket

Updated May 2018 – see bottom of page

bbboyBack in 2015 Packraft Store in Germany sold us a couple of pre-production Anfibio inflatable packrafting jackets in December to try out. These came without the big mesh pockets, unlike the current production item, left.
Called a Buoy Boy, an ‘inflatable jacket’ or buoyancy aid is all they claim to be, not a PFD, far less life jackets. They don’t even claim to have the rescue/harness elements suited to white water recoveries, as found on better PFDs. A warning label inside spells it all out. Instead your Buoy Boy bad boy is just a compact, unobtrusive buoyancy aid that’s well suited to sedate packraft touring.
bouyboYou clip the waist clip and hook the strap under the crotch to stop it riding up, as can happen with a regular PFD then zip up the front. Our prototypes had two ‘push and blow’ valve tubes inflating the two chambers (three breaths each). These chambers don’t cover the lower back which is composed of a thick, stretchy mesh below the inflated collar (left), so avoiding that lj55inelegant ‘pushed-up PFD’ look in your packraft. The rear collar around the neck might even float you unconscious, face up, like a proper life jacket, but that would be a happy coincidence and despite the appearance, it is not a design element.
lj44We weren’t even planning to take our regular PFDs on this particular trip, so a compact option came in welcome, especially when a late-night boat ride required them.
Best thing: it’s unobtrusive to wear deflated, doubling up as a high-viz vest whose benefits we also appreciated when road walking in the Scottish  midwinter gloom. We even inflated them while walking in freezing conditions to act as extra insulation, while at other times the Buoy Boy ought to be less hot than a regular PFD; another problem I’ve found when foam PFDs and paddling in 25°C+.

packrafting_store_logolj2Weight is from 340g to 400g for a Med/Large. My ‘M/L’ was a snug fit once fully inflated over all my mid-winter clobber (I’m normally 42″ chest). A great bit of kit that I can see becoming my regular day-tripping BA, especially when I have to wear one due to regs rather than need to due to conditions.

499_1Update.
I used my orange BBoy proto just about all the time as most of my paddling is flatwater and it’s great not to feel cluttered. I bought myself a larger L/XL with horizontal valve straps and very handy large frontal mesh pouches – just what was needed. Unfortunately it was black – I prefer brighter colours for safety and photos.
Now in 2018 colours are blue (S), yellow (M/L) and black or yellow (L/XL) – hooray! A roomy Large on me weighs 450g with crotch strapPrice is €99. More details and photos here.

boyboy

Replacing twist-lock valve on Alpacka

pakv1Ages ago I must have over-tightened the twist-lock mouth inflation valve cap on my Yak, probably ham-fisted ahead of a tense crossing. Actually it’s not so hard to do to the cheapo plasticy valves. And once you’ve gone too far and rounded the threads, the valve will only seal in the exact right position and with less tension than normal.
pakv3With a trip coming up, I set about replacing the black valve cap, but for the life of me could not locate one on the web in the UK, googling every permutation of ‘twist, lok/lock, valve, cap’. Fancier oral inflation valves exist for scuba BCDs but I wanted to keep it simple.
Trying to order from the US came up with $50+ postage for a 50-cent part. It gets even more fascinating but, to cut a long story short, eventually Supai Adventure Gear (there ultralight packraft previewed
here) sent me eight valves for $12. And then Alpacka unexpectedly replied and sent me a couple of theirs for free.
pakv4I thought just the softer plastic twist cap could be yanked off the white threaded section and replaced, but the blue cap Supais came threaded to the white bit, so perhaps caps and threaded sections are a unit and separating them pre-damages the threads. Don’t want that so the old valve needs to be cut off the red inflation tube.

Still here? Turns out the Supai valve has a bigger bore than my 2011 Yak valve but when trying to over-tighten a Supai valve as a test, I couldn’t manage it with my bare hands so it seems to be better than what came with my Yak in 2011. Looking closely it’s hard to see much difference in the design or materials, but even though the diameter is about 2mm more than the Alpacka valve, with a bit of glue as lube, it slips easily enough into the cut off red tube end.

Moral of the story: if you need to replace your thread-damaged Alpacka inflation valve you’ll need to cut the old one off and may prefer to replace it with a blue Supai unit (unless Alpackas have changed in the last couple of years).
In North America you can but these valves for a $1 or so from Advanced Elements, Feathercraft, NRS, Alpacka and Supai. The inflatable seats on my old Incept from NZ also had them, and iirc they were notably chunky. I’ve since learned that the Packrafting Store in Germany can sell you a twist valve for an Alpacka or a Supai.

Inflatable kayaks: glue and repairs

Updated Summer 2020

See also: Repairing a Gumotex Seawave
MYO D-rings

gluerepairs

It’s understandable to worry that something like an inflatable boat is a bit of a liability when out in the middle of a deep lake, hairing down some shallow white-water or far out to sea. This is especially pertinent if your only experience is a beach toy made of a thin and stretchy PVC film.

rep-hull

I’ve owned over a dozen inflatable boats and have only had one tiny thorn pinprick in the Inceptage-related fabric perforation on the ancient Semperit and a hole worn through carelessness in my Seawave.

It’s hard to think of anything puncturing my full Nitrilon Gumotex IKs or the old Grabner once on the actual water. What more often happens is some kind of accidental wear or rubbing when not paddling or during transportation, like the trolley wheels which wore a hole in my Seawave, or the windy tree branch which rubbed (but did not puncture) my Grabner (left). I also snagged my packraft’s uninflated floor on submerged concrete once, and added protection to the outside and padding on the inside to stop that happening again.

I’ve also travelled with cheap slackrafts that have got ruined within minutes and punctured every other day. You do get what you pay for. So when it comes to glue I’ve learned that preparation and application are vital to getting a good repair: rough it up; wipe it down with solvent, apply the right glue to both surfaces, wait, then slap on the patch and press down hard with roller to achieve a long-lasting bond. More below.

pvc-or-hypalon

Is your boat plastic or rubber?
As explained here, broadly speaking IKs are made of either rubber- or PVC-coated fabrics. Rubber-based Hypalon, EDPM or Nitrilon is most often used with the tubeless construction method.
On a boat like this, rough up the surface, clean with solvent (see below), apply the right glue and a same-material patch, all which needs to be done well as the patch is vulnerable on the outside. Or, you can just dab some Aquaseal directly onto a small hole in the hull to protect it from wear, as shown above left (not an actual puncture).

One-part glues
I’ve succeeded in gluing on non-critical D-rings onto Nitrilon Gumotex and EDPM Grabner boats using single-part Aquasure sealant/adhesive. Allow it to become touch-dry on both surfaces. Allowing Aquaseal to half-cure in air and then sticking together and letting it ‘seal’ to itself is a way of bonding anything – even non-compatible rubber-based Nitrilon to PVC, as I did here.
Their Seam Grip is a runnier version of Aquaseal to get into cracks and seams. Though I’ve not tried it yet, British-made Stormsure is the same thing.

In the UK you can buy Aqausure in 28g tubes from £6, or 250g for around £24. Unless you have a lot to glue/seal jobs, be wary of saving money with the big, 250-g tube; give it a chance and it’ll split and harden before you get to use it all, even if it’s effectively over half price.

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The other one-part glue I used on my PU/PVC Incept IK, Slackrafts and used recently on an old hypalon Semperit is Bostik 1782, not least because it once went real cheap on ebay.

glue-dring

I can’t say it worked that well on my Incept; two-part adhesive is always better. Even on the slackraft the Bostik softened and shrivelled the thin PVC. But on non-critical applications (D-rings and none-huge tears), 1782 seems to work well on hypalon (rubbery hypalon is always easier to glue than plastic PVC) and at £10 for 100ml was good value. Plus it’s a nitrile rubber/resin-based solution and I’ve found won’t go off and harden in the tube like Aquaseal often does. It’s my favourite, do-it-all, one-part glue

One glue I wouldn’t bother with is whatever Gumotex used (still do?) supply with their repair kits: Chemopren Universal (above left). It looks like the brown rubber solution you’d use on a bicycle inner tube. I remember trying to use it on my old Gumotex Sunny years ago and finding it was crap. Back then it may have been me, but I tried to use Chemopren again recently on my hypalon Semperit and it wouldn’t even adhere to a roughed up, MEK’d surface! To be fair it might have been many years old, but so are my other glues.

Actually what came with my Seawave in 2014 is a small tube of ElaStick (above right). But it looks like a generic polyurethane do-it-all glue. It remains unused with the boat and probably will stay that way until it goes off. I’d sooner rely on Nirtile-based 1782 or Aquaseal for field repairs

Two-part glue

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For important jobs use much stronger two-part adhesives suited to actually assembling air boats as well as making more permanent fittings and bomb-proof repairs.
At about £15 posted for a 250-mil tin, Polymarine 2990 Hypalon adhesive (left) is much cheaper per ml than Aquaseal or Bostik 1782. In the UK Ribstore and Ribright sell similar stuff (below) just make sure you buy for Hypalon or PVC. I’ve used it to glue D-rings onto my Grabner (more here), floor patches to my Alpacka, latex socks to my dry trousers and patches as well as repairs to my Nitrilon Seawave, It sticks like shit to a s***el.

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In 2017 when I dismembered an old IK, I was easily able to pull off recent patches glued on with Bostik by hand. But I could only pull off Polymarined patches with a pair of Knipex hydraulic trench pliers and even then, the patch coating pulled away from it’s core (lighter exposed weave below) or the patch remained stuck to the boat and instead pulled off the dead’s boat’s hypalon coating revealing the fabric’s yellowed core or scrim. The two recently glued surfaces could not be separated. They say the mixing of the two components causes a chemical ‘vulcanisation’ and molecular cross-linking which creates a very strong bond. Mixing and applying two-part is a pain, but it works.

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Get a good roller

sealey

Single or two-part, once you apply your patch, roll it very hard with something like the classic Baltic-pine handled Sealey TST15 stitch roller (left) aka: tyre repair roller used for innertube and tyre repairs. The knurled metal wheel set in a solid handle applies much greater pressure than a wide plastic roller I used to use, and they’re only about a fiver on ebay. Buy one now so you’re ready.

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Bladder boat and packraft repairs
With smooth-skinned Alpacka packrafts, they recommend two-inch wide Tyvec adhesive tape produced by DuPont. Just peel off the back and apply a section on to pricks or small tears once the surface has been cleaned and dried. No need for roughing up, but a quick wipe with solvent won’t do any harm. Larger tears can be sewn then taped. Tyvec will work on urethane IK bladders and extra tacky duct tape or gorilla tape will do too, but is unlikely to remain impermeable once immersed for a while.

Aire-style bladder boat repairs are actually easy. According to Aire’s youtube vid, you unzip the hull shell, slap on a bit of Tyvec on the split, tape up the inner side of the hull shell gash to keep out grit, reflate and off you go. You can glue up in the usual way later, if necessary. I had the feeling that on my Feathercraft Java the urethane-coated sponsons made of thin ripstop nylon fabric (like tent flysheet material) couldn’t have been securely repaired with tape. In fact, it would be difficult to bond anything well to the slippery nylon fabric compared to smooth urethane plastic or hypalon-like surfaces, but perhaps once inflated the seal would have been fine.

Good article on how adhesives work

Cleaning solvents

foamdandingblock

Once you’ve done your roughing up (sandpaper or a foam abrasive sanding block, left) you need to clean off the residue as well as any oil or grease present. Anything will do in a pinch; alcohol and spirits, after-shave or nail polish remover (acetone), lighter fluid, white gas or petrol of course, but not oilier diesel, aviation fuel or Nivea for Men. Bleaching agents aren’t the same thing. In the end just use water to remove the dusty, post-roughing residue, and on a cold day it can help to warm up the damaged surface to cure the glue more quickly.

toluene

For a travel repair kit a tin of lighter fluid (same as white gas) or nail polish remover (acetone) are easy to buy and handy to pack. Back at home I’ve found MEK (Methyl Ethyl Ketone) is inexpensive at £9/ltr and hideously effective. Acetone is even cheaper and perhaps less extreme – all we’re really talking about is cleaning off any grease and the dust after sanding.
They say MEK is for PVC boats rather than Hypalon, but on a thin plastic slackraft the PVC will shrivel up before your eyes once MEK’d. Even on rubber-based coatings use MEK or similar toluene sparingly. Expect some colour to come away on the cloth and the coating to soften at bit: good for adhesion. Note the NRS video above specifically recommends toluene (the second ‘T’ in ‘TNT’ explosive, fyi) for hypalon. On ebay uk it’s the same £9/ltr but they won’t post this stuff around the USA.

Huge tears and bear bites

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If you have a huge gash, as in the folding Klepper’s hull below, sewing is the only way to contain the tear when applied to an IK. Then apply a huge patch with adhesive, as normal. The boat below caught a cut-down metal fence stake buried in a shallow river bed and was actually sent back to Klepper for professional repair. It’s tempting to think an IK’s pressurised hull would have skimmed over the stake rather than snagged it. The smaller 1-inch L-tear on the left was glued with a 5-inch patch but the 30-year0old IK proved to be totalled.

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Inflatable Kayak Construction Part 2: Hull Forms and Rigidity

Part 1: Materials and Fabrication
See also: Drop stitch IKs (or more below)

Updated Summer 2020

An inflatable kayak differs from a hardshell in many ways. An IK is usually wider and sits higher in the water because the sides and floor are effectively several inches thick, not a few millimetres as on a SinK (‘sit-in hardshell kayak’).

grabanana

While length-for-length an IK is usually lighter than a SinK, it’s rarely as rigid. On a short, rock-bashing, creek boat this can either be unnoticeable or even a slight advantage when it comes to impacts.

But here at IK&P we’re into long IKs of 3.6m (12 feet) or more. Years of experimentation have proved that this adds up to a do-it-all boat that’s manoeuvrable on rivers up to WW3 and fine for coast hopping up to Force 4. Such a boat can either carry a second paddler or a solo camping payload for a few days touring while rarely weighing more than 18kg or 40lbs and so can be carried over short distances.
Problem is, when an IK gets beyond a certain length it can sag in the middle with a single heavy paddler (me?!). As on my old Feathercraft Java (below), even with rocks piled in each end or my ‘uphill‘ Grabner, above left. There are various ways of making a long IK rigid, but first…

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Hull profiles
A hardshell sea kayak can have various hull profiles that, combined with other design elements defines the boat’s stability in various sea conditions. The picture on the left may be merely down to timing but illustrates how a very long SinK on the right runs more level than an IK bobbing about on rough water, partly because the hardshell is heavier and less buoyant, but also because – like a 29-inch MTB wheel – a long, slim kayak ‘flattens out the bumps’ better than a 26-er. Some sea kayaks with V-shaped hull profiles become more stable the rougher seas get but at the cost of stability in flat water.

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Left: Grabner Amigo – right Incept K40.

The flat and wide hull profile of a traditional IK is not so sophisticated, nor is the boxy (hard chined) profile of a full dropstitch (F D/S) IK (right). For better or worse, most IKs are as stable as a raft. The key is to find a balance between reassuring stability and performance-killing width. On an IK I find the optimum width is around 32–27″ (81–69cm). On rivers or at sea an IK hull is usually very stable until things get exceedingly rough. I’d guess that the two hulls pictured left (a red Grabner Amigo and an Incept K40), the less boxy red boat would take more leaning over (or steeper waves) before it suddenly tipped. However, it’s pretty obvious why the grey Incept was some 20% quicker through the water, as was my slender FC Java.
Note that the width of an Full D/S IK can be misleading as the flat sides taper in to the floor. Above right a Sea Eagle Razorlite listed in the table below as 76cm and which is fast, but some find a bit tippy.

The Incept was 3.5 inches narrower than the Amigo and has a more pointy bow (its stiff fabric and being 15% longer were also factors). And yet, this 27-inch (67cm) wide Incept could never be described as ‘tippy’ even in seas up to F5-6 (other problems did occur).
It all proves that an IK doesn’t have to be ridiculously wide (as left) to be stable. Many, many otherwise functional-looking IKs are up to a foot wider than the Incept. Even if you are extremely nervous about padding and stability, such width is excessive and makes paddling inefficient.

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Stability and centre of gravity (CoG)
Having said all that, an IK needs to be a bit wider to compensate for the fact, that compared to a SinK or a packraft, you’re sat higher above the water on an air floor and probably on an inflatable seat too (graphic, left). This adds up to a higher centre of gravity which affects stability, just as a 4WD is top-heavy in turns or on slopes compared to a McLaren F1. Your butt is the axis on which you pivot when wobbling/capsizing and on a hardshell, a folder or a packraft you sit just an inch or two below the water level: lower CoG = better stability without resorting to width.

AESE

Then, when you factor in less common self-bailing IKs, with an even thicker floor to be above the general water level, again the boat becomes less stable unless it becomes wider. You can see how high the floor appears on the self-bailing AW StraightEdge on the left and the Feathercraft Java, below.

javabailer

Also, your physique/size can also produce an impression of instability in otherwise well-liked boats that most paddlers find fine. At my XL size, I found my old Gumotex Sunny’s 30″/76cm beam was more than enough and at 27″ my Incept was also fine. But the 28-inch Java (above) and even more so the as wide Mk1 Safari (a self-bailer) were a bit tippy. The graphic below shows a regular IK in calm water and then swamped in rough water (centre). Right is a self-bailer like the Java or StraightEdge which drains in the same rough conditions but requires a thicker floor and/or higher seat to keep you dry. Result: IKs like Java or Safari Mk1 get tippy (for some), or you sit in water (not ideal) or the IK becomes over-wide (also not ideal but the best compromise for white water).

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comeonibeam

IK floors: I-beam and drop stitch
Traditinal IK hulls had three chambers: two round side tubes and a flatter, wider floor composed of many interlinked tubes (left). And in case you’re wondering, an inflated floor is an important element in an IK’s buoyancy. Obviously, round sided tubes are easy to make and take on the required form on inflation. Providing it’s well made, modest over-inflating is OK as the round profile distributes pressure equally.

Steel-IBeam
javasection

The flatter, lilo-like floor is another matter. To make this section the floor is joined top to bottom with I-beam fabric dividers resembling the steel beam on the right. It’s said this is the most labour-intensive and expensive part of traditional IK fabrication and explains why easy, slip-in bladders are preferred by most manufacturers, as on the Java, left. It saves time, effort and cost. Without I-beams or other constraints, once inflated the floor would balloon into a useless rounded form.

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But with I-beams too much pressure can pull the floor dividers apart. Result: the floor balloons, the hull becomes deformed and a repair is very complicated or expensive. This is why some IKs including better Aires, some Gumotexes, bigger Grabners and Incept Ks feature a pressure relief valve (PRV) in the I-beam floor. Even though this part of the boat is in the cooling water, it is vulnerable to damage from excessive pressures which can occur when an IK gets hot when left out of the water. Although it had four separate bladders as opposed to an I-beam floor, I learned this lesson the hard way when my day-old Feathercraft Java went Krakatoa on me one sunny day in Colorado.
Following that disaster, one thing I liked about my Incept K40 was it had PRVs on all three chambers. I no longer needed to be paranoid about exploding my £1500 boat by accidentally allowing it to overheat out of the water. I could leave it on a car roof or a beach all day and air would purge harmlessly via the PRVs at the price of being a bit limp once it all cooled down back on the water. A quick blast with the K-Pump was all that was needed. On my Seawave I added PRVs to the two side tubes to get the same benefits.

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Other ways of making an IK hull stiff
Whether your IK is bladder (as left) or tubeless, one way to achieve a rigid hull is to use twin side beams; two thinner tubes stacked over each other as pictured left. There may not seem much in it, but two tubular sections resist longitudinal bending better than one big tube, and all with a negligible gain in weight. This design also has the advantage of making a slimmer boat compared to a fat, single side tube. Higher sides without width also keep out waves but do make more windage – the bane of IKs. Examples of twin side tube IKs include the Grabner Holidays, Incept Ks and the Sevylor above, the old Semperit Forelle (the original modern IK) and Gumotex Seakers. At the time, Gumotex weren’t able to make a 5-metrelong Seakers out of Nitrilon that was suitably rigid so the Seaker (below) used a Korean PVC-coated fabric called Mirasol, but ended up weighing a staggering 34kg – double the Incept.

backbone

A cruder method includes fitting metal frames or spars. Advanced Elements offer an optional Backbone (right) for some of their kayaks, though I’m still unsure whether this is as much to impart more of a ‘V’ into the otherwise flabby hull floor and so improve tracking and speed. A picture here, and a forum full of discussions somewhere here. As the picture right at the top of the page shows, the metal frames in the FC Java (see also green graphic above) didn’t keep that boat rigid, at least with my weight.

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The newer Neris Smart IKs (left) use more substantial metalwork based on their folding kayaks. Using metal frames is a valid way of gaining stuffiness, but Incept, Grabner and now dropstitch have proved that you can design an IK without resorting to such measures. Just as I’ve found with the Java and Grabner’s alloy backrests, incorporating bend-prone metal bars with inflatables isn’t a good idea. If nothing else it makes damage-free transportation more of a gamble.

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This sagging was always a problem on my 13-foot Sunny (left). While paddling in France one time I tried putting a 1-metre plank under the seat to reduce the mid-sag. It did seem to give me an extra inch or two of draught in the shallow river. Later, I tried a couple of straight branches jammed into the cavity between the floor and the side tubes.
My unscientific impression was that by levelling the boat out in the water the Sunny was indeed faster and more responsive. The fact that later on the river sticks popped out of their slots through some rapids suggested how much the 0.2 bar (3psi) Sunny flexed in rough water. Later I tried fitting some chopped-down cheapo paddles. Some form of attachment for the poles needed to be glued to the 3-inch wide flat section where the floor meets the side wall (more here). I got as far as this but then gave the Sunny away. Had I finished the job I’d have expected a little more response to the paddling stroke with a less flex in the waves.

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dsfabric

In the last few years drop stitch (D/S) panels have appeared on a newer IKs. This technology is derived from the popularity of inflatable iSuP boards (above) which clearly need more pressure than your average airbed or IK. Lord knows how they make it, but it’s a way of joining two sheets of coated fabric with countless loose nylon filaments, all the same length (left).

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When the two sheets are sealed to make a chamber and then pumped up, the space yarn acts like multiple ‘I-beams’, distributing the tension over the entire surface area. Result: pressure can be up to 10 psi or nearly 0.7 bar’ – four times than a tubed IK, making the boat much more rigid. More on DS IKs here.

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Incredibly, in the late 1950s Goodyear used a the same D/S technology to design an experimental inflatable aircraft, the Inflatoplane (above). A light and portable plane, not an inexpensive inflatable decoy as armies have used previously. It did actually fly but as a project was abandoned when a valid military use for ‘an aircraft that could be brought down by a well-aimed bow and arrow‘ couldn’t be found. Now there are IKs like the Kzone Slider below which are fully made from DS panels.

SLIDER

They are only just finding ways of making a D/S panel that’s anything other than flat as an ironing board, but they’re getting there – the Decathlon Strenfit X500 (below) currently leads the way. While full DS will make a kayak very rigid, the smooth, flat underside and basic, box profile may make handling in rougher water tricky. One side benefit of the I-beam floors on ‘tubeless’ IKs is the channels formed by the parallel tubes create a keel effect.

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On the Sea Eagle 385 they’ve incorporated a drop-stitch inflatable front keel (left) that looks rather exposed and prone to damage. You’d also assume this makes turning difficult, although with enough paddle cranking and some edging any IK can be turned easily enough.

Now they can manufacture DS panels which are more sophisticated than the slab-like platform shown below, mimicking the complex forms and curves of a molded hardshell kayak. It marks a big step forward in IK design. Currently the Gumotex Rush (part–D/S hybrid) and especially the Decathlon X500 have upped the game. More than just 3 planks making a paddling trough, Gumotex have managed to integrate D/S panels into the bow and stern, giving a more hydrodynamic form on the sides.
Drop-stitch is the future of IK design and I wouldn’t be surprised if it somehow moves towards packraft floors too. Longer boats like my Nomad S1 could benefit from the added support of a separate D/S floor.

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More kayak disc sailing

The IK & packraft sail Index Page

Windbag update 2016: the 3mm-thick 305cm-long glass fibre rod snapped. Not surprising with the bending it gets to fold down, but I doubt it’s worth repairing. I bought another length via ebay for a tenner. I went for a 3m section which is 5cm short (next length being 5m) but the sail can accommodate dektentthe slack. It felt more flexible but within a couple of days that broke in two places too. If I run 3mm rod doubled up I presume the bending forces will be the same, but if I run thicker rod I presume it won’t fold down three times to the compact 30cm diametre disc.
windppLooking again at the original Windpaddle, it does seem much of the cost is explained by the ‘proprietary’ composite rod they use, and there seem few easily found online reports of breakages. Prices seem to have dropped quite a lot too (as they have for the ebay knock offs by 50%). Could it be you get what you pay for after all?


 

sai01The other evening I hooked my old home-made disc sail onto the Grabner’s bow (left and below) and took it out on a loch to remind myself that it wasn’t really that good. As before, I found it difficult to get a good run before it flapped out or otherwise lost its drive.
sai-discMy Pacific Action V-sail will work better, but fitting that to the Amigo may require more D-ringing. I like the compactness and simplicity of a disc sail, but it was suggested that dishing like a bowl was the key to holding the wind and maintaining steady progress, even if it may be less effective tacking across the wind.
ParachutaiSounds plausible and WindPaddles are clearly made like that for a reason. Since then it occurred to me that’s why classic ‘descending’ parachutes (‘reverse’ sails) are bowls and not flatter discs which would shoot across the sky. Before I set about recutting my disc into a bowl shape I checked WP prices on ebay and spotted what looked like a knock-off: ‘Canoe sail kayak sail wind sail‘, now just £17 delivered. Cheaper than sewing and at 115cm deployed, it was midway in size between WP’s Adventure which at the time was selling for no less than £155 in the UK (now £110 with smaller Scout for £90). Someone assure me that a WindPaddle costs even a fiver to make in China, but see top of the page.
sai10sai-attachAnd better still, the no-name windbag folds down into three hoops of just over a foot in diameter (right – smaller than my red disc sail). Plus there’s an elastic hoop to keep it like that and a carry bag for the long walk back to the van. Out of that bag, the only changes I made were to replace the too-short control strings with my tape off the red sail which I find easier to handle. I reassigned a sling to hook the sail’s base to a floor D-ring back from the bow (above left). That was already fitted and was the only adaption I needed to mount the sail to the Grabner.
sai03The day before, with the visiting Nimbus family we’d paddled round the Ristol isles. Over lunch on Ristol beach I took my new sail for a burn up. First time out, not bad at all. I got a steady run and up to 3.9 mph on a breeze of no more than 15 mph and with very little faffing. The prospects were good. More wind was needed.
Incidentally, on the beach I noticed how very, very much unlike a sea kayak the Amigo really is. Alongside my old Incept, let alone the lethal Scorchio HV (right), the red boat looked sai12like one of those horrible inflatable kayaks you read about, except it happened to be clad in bomb-proof hypalon and pumped up like a basketball. And by the way, I finally fixed the seat in the Grabner with a rather obvious solution. Details on the Mods page if you’re interested.

sai-mullaEarlier on, coming round the southwest corner of Eilean Mullagrach, (right), the swell bouncing off the cliffs and crashing over outer reefs looked intimidating. Though we all managed fine, it was everyone for themselves. With heads bent to the task, the comparative speeds of our four boats was clear to see. Way out ahead and longer than your average four-door car: the cheddar-coloured P&H cheese cutter. No far behind, 12-year-old Boy Nimbus darted along in his 12-foot Carolina (later I GPS’d him at 6mph, same as the HV). sai-2botsFurther back Mama Nimbus and little sister Nima in the K40, all hands on deck. And out back Grabner’s hypalon clog – splish-splosh, splish-splosh Slap. Checking the GPS data (above left), the speeds weren’t so bad, it’s just that in the rough the hardshells cut through some 30% quicker.
A few days later the Solar was stacked on the Amigo (right) and I realised it was only a foot or so longer than the Gumotex. In that case the Grabner does pretty well for a 12-foot four-, 31-inch kayak that hauls two paddlers.
sai-windsBack to the sailing. Next day winds were forecast at over 25 mph (right) but as it was warm and only a 5-minute drive to a Loch Vatachan round the back, it was worth a crack.
sai-splasherA short pre-paddle suggested my cheapo windsail would probably get ripped off and blown to Lochinver, or else see me roll off the back of the kayak as it shot away from under me liked a snatched tablecloth. Upwind I couldn’t exceed 2 mph (left), but skimmed downwind at up to 5.5 mph providing I kept the stern right on the wind. And while I was out here, side-on to the one-foot fetch the Amigo felt secure, so not a completely wasted outing. I’d never set out to paddle in such conditions normally (actually I did once), let alone try sailing (actually I had once) so I called it off. Later, Ardmair weather station confirmed the wind had been howling at a steady 35 and gusting to nearly 50 mph.
sai-boatsWith the Nimbii, we ‘yaked over to Tanera Mor one afternoon; three IKs and two SinKs (left). I can see it from the window now, but realised I’d never actually walked up to the 124-m (400-foot) summit of Tanera Mor for a look around.
sai-tansouthUp on top a string of islets lead to the twin humps of Priest Island, 4.5 miles in a straight line (right). It was a ten-mile round trip I’ve mentioned earlier but may be beyond reach this time round.
Paddling back from the island, Mama Nim found my old Incept had picked up another pin-prick hole in the side. Wtf is happening to the K40? It’s a lot better than the armchair -wide Sevy they were borrowing before, but three holes in four outings? And it gets worse. On leaving the island the wind dropped to nothing so sailing was off. Instead, we were plagued by sea midges which rise from their lairs as soon as the wind turns its back.
Another day and a healthy northerly forecast at 10mph on the BBC which might mean 15 in real terms. I set off with Nimbus in his Scorpio ‘PK’ (plastic coffin) for a look at Tanera Beg’s arch he’d missed on previous visits. It’s a nice arch; we passed it a couple of weeks back, two-up in the Amigo.
sai-keensOnce clear of Old Dornie I threw the sail out and trotted along at 3.5 mph which won’t be giving me any nosebleeds but I suppose must be classified as progress. At least I found a good way of stashing the sail. Seeing as it’s right out on the bow, refolding it down to three hoops isn’t practical on the water without help or taking risks. But I could just pull it back and tuck the squidged sail under my feet and between my legs (left). Down here there’s little risk of it self-deploying and jumping overboard to become a most unwelcome sea anchor, but it can be thrown up in a jiffy to catch a breeze, just as with the PA.
sai-paddOnce we got to the two Taneras’ In-Between islands the wind remained but the waves were blocked so I threw out the air bag and trickled along again at about 3.5mph again. Then it occurred to me I could hold the sail leash in my teeth and paddle. I swear, Da Vinci must have felt like this on his good days. That worked well too: getting on for 5 mph but without the paddling effort to make that speed unaided. Plus it felt better than having the sail hooked to my pfd and stopped me talking unnecessarily.
sai-archersOnce past the In Betweens we crossed over to the arch (left), but found we were a metre short of water. Still, high or low water it’s a great mini-destination some three miles out of Old Dornie (see maps below).
sai-calmacerNow the easy ride was over; it was going to be a solid old hack back into the wind for Old Dornie. As we turned we were a little perturbed by what looked like the  Stornoway ferry heading right at us. I’m sure it never came this far north, was the captain asleep at the wheel or taking a deeper channel on the spring tide?
sai-breakerferryAt the last minute the CalMac turned away and a calamity was averted. A few minutes later its wake rolled in, breaking a couple of feet high just as we  passed a reef. It looked like a good picture so I sent Nimbus back for a shot (left) but by then the best of the surf had passed. If that was the swell kicked up by the ferry from a mile away and before it hit full speed in the Minch then I’m glad we keep our distance.
ferryspdTime to put the camera away and knuckle down for an hour’s bow slapping to Old Dornie. As I’ve observed before in such conditions, Nimbus in his blofieSinK paddled like he was stroking a cat, gliding through the waves in a seemingly relaxed procession. Me? I was loading 16 tons and what did I get? Slipping back further and deeper in bilge. Still, not alone for a change was less unnerving and I quite like a good work out on familiar terrain. You dial in the effort you know you can sustain for the duration and progress at whatever speed that delivers. From the graph above that added up to about 2.5 with occasional surges to 3 mph when my technique briefly hit BCU targets. The P&H PK seemed to hold a steady 3mph without trying.
sai-splarshThe wind had failed to live up to the forecast promise of dropping around 6pm and out in the mid-channel a few white tops developed; for me in the IK usually a warning sign it’s approaching the limits. I will speculate that I shipped less water than I would have in the Sunny which is a similar type of IK. Partly because of the upswept Amigo’s bow that front or rear doesn’t seem to be as much of a wind catcher as it looks. And perhaps too because the boat doesn’t bend with the swell.
In fact it was fun slapping the fat bow against the oncoming waves as I slowly hauled my way closer to Dornie. Old Man Nimbus can read wind speeds like a Tubu hunter reads the sands. He estimated it was blowing at 8m/sec which in English translates to 20mph. I’d angleferryhave guessed a bit less, as with the spring tide at full flow against it, it didn’t seem too much in an IK (as long as land appeared close by). As we neared the harbour a couple of other SinKs slinked by, tucked right under the shore, out of the wind. Get out here you cowards!

No Name wind sail
So – my conclusion of the no-name wind sail? Well, it’s a WindPaddle at the right price. Easy to fit to my boat and doubtless many others, easy to temporarily stash on the move and probably easy to repair. And easy to steer too; pull left to go left, usually. With the window pane it’s much better than my home-made flat disc of course, plus it’s less bulky and complex than a V-sail, even if a V will give you nearly 90° reach either side of the wind.
Surprisingly I haven’t found the lack of a rudder an impediment with the Grabner. Though there’s a bit less directional control, at the typical sub-4 mph speeds you can drag a hand or a paddle blade to bring the nose around. And interestingly, providing you’re close to the wind and holding a steady course, the sail worked pretty well when paddling with the leash in my teeth like the 3.30 line up at Cheltenham. I can’t say I ever managed paddling with the Pacific Action on the Incept for long before it flapped out. Plus there’s plenty of scope for hooking up some self-jamming cleats (left – more here) like I ran on the Incept.
Above all, the no-name air scoop is great value for money for the performance it delivers. For thirty quid it wouldn’t be worth making your own. Next job – see how the little Alpacka handles when yanked along by the wind sail.