Tag Archives: K-Pump Mini

Pumps for inflatable kayaks and packrafts

Updated January 2023

See also:
Inflation valves and PRVs
My PoV on electric pumps for IKs
Tested: Flextailgear rechargeable packraft pump

Your inflatable packboat needs a pump to take form as well as to top-up once on the water. These functions may be best performed by two different pumps. It seems the era of the folding bellows footpump (left) is over and even low-pressure IKs now come with some sort of barrel pump.

A plastic-bodied barrel or ‘stirrup’ pump is light but bulky so not something you’d want to tour with. They’re usually used for pumping up high volume/low pressure things like whitewater rafts, lots of IKs or kite wings. Some pump on both up and down strokes to fill your boat faster, but as you reach higher pressures they automatically or manually switch to downstroke-only inflation to reduce the effort. They work best on flat, firm ground where you can stand on the stirrup plates and get stuck in. The excellent Bravo 4 RED Kite pump below (newer ones are blue) is still well under £20 and will pump up an IK in 5 minutes.

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I got a Bravo 6 with my Seawave once but found it hard work – who knows why. The cheaper Bravo 4 does claim to be an ‘R.E.D’ (‘reduced effort device’) and I can confirm this isn’t some gimmicky acronym. The other port on the Bravo’s handle can be used to suck air from an IK so it rolls up good and flat; you can see creases forming in the hull as you suck it down.

I left my Bravo 4 RED at home one time so bought a Sevylor RB2500G barrel pump (below left) for a tenner. Same size as the Bravo barrels, it did OK for the awkward topping-up of my Semperit’s lilo plugs. It came with push-fit, lilo-plug and bayonet adaptors and sucked as well as pumps. But pumping up my Seawave from flat was exhausting towards the end: I actually got out of breath and had to rest! Morale of this fascinating anecdote: get a Bravo 4 RED and the right adaptor for your boat.

Not all barrels have a built-in pressure gauge which is obviously dead handy in getting the right pressure without needing to faff about with a separate manometer (see below). It’s worth an extra tenner to get a built-in gauge, especially with DS boats. Or fit an inline adapter manometre: see below.

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The K-Pump Mini (above right) is a handy top-up pump or compact 600-g travel pump. It took 15 minutes to fully inflate up my 14-foot Seawave; the push-fit nozzle works on any IK with one-way spring valves. You have to press and hold the nozzle against the valve. Using it a lot one time, I got the feeling it might break something or wear out the seal (which needs regreasing once in a while). I’ve also used the K-Pump to top up my Nomad S1 packraft which was too big and long to inflate firmly with just its airbag. Fuller review of the K-Pump Mini here. They’re hard to find in the UK, the very long, and slim US-made K-Pump 200 (above right) may also be suited to higher-pressure dropstitch applications.

Packraft mini-pump for topping up IKs

Another idea from Seawave-user Jason, is adapting a packraft mini-pump (left) for topping up. It may take a while but he says it’ll reach 4.5psi eventually. Less bulky and much cheaper than a K-Pump, they’re actually for footballs and the like, so you can find them on eBay for a tenner.

Left, the Bestway Air Hammer is an ‘upside-down’ barrel pump which comes in three sizes and costs from just £6 on eBay. If you don’t want to paddle with your full-size barrel pump, the smallest Air Hammer could work as a compact top-up pump like the K-Pump, but a tenth of the price. The one on the left came with a ROBfin and was rated at 4psi.

High-pressure pumps

More and more IKs now feature super-rigid, high-pressure dropstitch hulls – either just floors or the entire hull which runs 2–5 times higher pressures than regular IKs. Your old Bravo footpump will blow its brains out trying to reach a typical 7-10psi.
Barrel pumps with long, slim bodies, as opposed to the shorter, stockier examples above, put out less volume (DS IKs have less volume anyway) but can more easily attain higher pressures. It’s something to do with the ø of the pump face x the stroke. You don’t necessarily need a super high-pressure iSup board pump.

Left: Bravo Alu RED from £16 • Middle: Bravo 110 >£40 • Right Itiwit (Decathlon) £20

Some of these pumps may be double action. At a certain psi they become single action (downstroke only). I believe the Bravo Alu 4 RED (0.8 bar) works like that. Or they have a switch to do the same and help attain higher pressures. It works. Whatever pump you get for your DS IK, make sure it is rated to comfortably exceed your DS boat’s pressure rating.

What I call ‘raft’ valves

Bayonet nozzles for ‘raft’ valves.
Who would have thought there’s something to be said about bayonet nozzles? Well there is. There are two types: plain (below right, Gumotex) and crossbar-peg or detent (left, Bravo). Both need soft spacer washers to fit snugly against your boat’s raft valve, but the small peg inside the green one will press open your valve stem as you connect it.

You will notice a similar peg on car tyre inflation hoses and also on a hand manometer (below). A manometer can’t get a pressure reading without this peg partially opening the valve as you push it on. A nozzle with a peg/detent means that:
a: you’re not pushing the valve spring open each time you pump (easier pumping) and
b: if your pump has a manometer you will get a constant/live reading as the pressure climbs which is the point of having a built-in manometer. The Bravo one goes from 3 quid; search: ‘Bravo Adjustable HP Valve adapter’.
The only drawback might be that you need to remove a pegged nozzle carefully with Push-Push (Gumotex) valves. Normally a little air escapes as you do this, but if the valve doesn’t spring back closed, air will rush out. Turn slowly then pull away briskly; you’ll get the knack.

Pressure gauge (manometer)
Until I got a Grabner which has no PRVs but ran a relatively high, 0.3 bar (4.3 psi), I never bothered with a pressure gauge (manometer, below) and just pumped up by feel. A lot of people do this. Since then, I ran a Gumotex Seawave and fitted PRVs to all chambers. That meant I still didn’t need a pressure gauge to get the right pressure; I simply kept pumping until each PRV hissed: the boat was then at operating pressure. My Seawave 2 was left stock (no side PRVs) so I have got into the habit of keeping a Bravo manometer with the K-Pump Mini and checking the sides at each paddle when I top up. I have checked this manometer against the floor and it measured 0.25bar which matches with the PRV rating, so I think it’s pretty accurate. Try and get a model with a range of no more than 1 bar (as below left) as that is the range you’re working in. At the moment, Sea Mark Nunn sell it in the UK.

With high-pressure DS IKs, you probably want a pressure gauge as the boat will perform best at the right pressure which may be higher than you’re used to.

Add a manometer to a barrel pump
I’ve had a couple of 0.8 bar rated Bravo 4 Alu R.E.D barrel pumps over the years, including with my Zelgear Igla IK to (a typical DS pressure). In the UK they go for under £20 without a gauge – a real bargain for a powerful and smooth acting two-way pump. The next similarly rated Bravo barrel with a gauge is nearly fifty quid. That’s inflation for you.
The good thing is you can now buy the long lost SP90B inline adapters with a manometer in the UK. The manometer screws into the black plastic adapter which has the male and female bayonet fittings to attach to the 3 Alu’s pump hose and the handle.

Packraft Pumps

Packrafts used to be inflated with a featherlight airbag which came with the boat. A nozzle on the bag screws into the boat’s valve and you scoop air into the bag (easier with a breeze) and ‘bear hug’ it to cram the air into the boat. It’s takes about ten scoops to inflate a boat this way, then unscrew the bag nozzle and quickly screw on the valve without losing much air.
Next, you top off by mouth: the firmer the boat the better it rides. In the video below (speeded up x 15) from walking up to a beach with my paddle in my pack, to loading up and paddling away took 8 minutes.

Things have moved on: most packrafts now have one-way Boston valves which makes topping up much easier. And for those who don’t have lungs like Luciano Pavarotti, you can use a light and compact mini handpump (below) to top up and get the boat good and firm.

Firm boats paddle better but like IKs, a packraft that’s been firmly inflated by hot ambient air on land will go soft once cooled in the water and will need more topping up. The pump above has a hose which means with a Boston valve-equipped packraft, you can top-up on the water, if needed. A good packraft should hold air for days at a time, but don’t leave it fully inflated and out of the water in the hot sun. The air inside heats up and expands, pressures rise and the seams will get strained.

A mini handpump is very handy to get a good fill into your packraft. But now there are tiny rechargeable electric pumps which will do the job of the air bag. More here.

Mini electric pump

Grabner Amigo kayak modifications

Amigo main page

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Unlike my previous new IKs, out of the bag you don’t get much with a Grabner Amigo. In fact you don’t even get a bag. With Grabner IKs just about everything except the repair kit and air you pump in is an extra which undermines the otherwise striking 14kg weight. To make up for this dearth of equipment, in the catalogue they even list the specification label (right) as among the boat’s standard features!
So my Amigo added up to the bare boat with carry loops at each end and two backrest bars. No seat, skeg, pump, lashing points (D-rings). On purchase, I ordered half a dozen D-rings and a pressure gauge. The rest I’ll work out myself. Having learned what’s needed over the years, that suits me fine.

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Manometer

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With the high pressures an Amigo runs it’s great to finally have a pressure gauge that’s easy to use (left). There are no pressure release valves (PRVs) to stop an Amigo splitting a seam if left out in the hot sun, so it’ll be a quick way of keeping tabs on the boat’s pressure or ascertain it’s at full charge. I’ve added a marker in pink to easily line up with the Grabner’s rating of 0.3 bar (4.3 psi) – not 4.3 bar as I mistakenly did once (the old eyes are going…).

Fitting a tracking fin

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Before the Amigo even got wet I glued on a Gumotex skeg patch (left, £12) and thick plastic Gumo skeg (another £12). All up cheaper and stronger than Grabner’s similar slip-on €60 alloy version. I took a chance using MEK to wipe and one-part Aquasure to glue the Nitrilon patch to the Grabner EPDM hull as I didn’t have proper two-part adhesive to hand. I figured it would work OK as a skeg isn’t under great strain like thigh- or footrest D-rings, for example. Years later, no problems. Apply a thin film of Aquasure to both surfaces; wait half an hour, then press down with all you’ve got.

A skeg is a pain in the shallows or when dragging a heavy-laden boat over the heather; that’s one thing I liked about the Incept’s hinged rudder, but I can’t think how to make an effective hinged skeg except the way Feathercraft do it on their self-bailing Java (it slips up and down through a slot in the self-bailing floor).

A slip-in skeg can’t be slipped off a fully pumped up boat, at least one like a high-pressure Amigo, though actually after a couple of months it’s less tight and can be done. Being able to do that is very handy for portages or grass-dragging, though the skeg itself looks pretty tough. Of course, an IK works without a skeg, but on coastal waters they’re a good idea. More on that topic here.

Pump

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The Amigo uses more secure bayonet inflation valves which with the right adaptor (see inset below left) don’t pop out at the high pressures (0.3 bar/4.3psi) this boat requires.).
Pump hose-end bayonet adaptors are easily bought in the UK from RIB suppliers on ebay. Inset left, the black one is what Grabner sell with a fitted fibre sealing ring and steps in the bayonet to suit different valve depths. The ‘butterfly’ finger tabs make this easy to twist in place, too. The green one uses plastic spacers held in place behind a black rubber washer to get a good seal. You wouldn’t want to lose these push-on seals and it’s hard to twist in place, so for the moment I’d say the Grabner one is better. Write that down, quick!

A now almost extinct yellow-hosed Bravo foot pump that suits some Gumotex can’t manage Grabner pressures, at least not my aged Bravo which hisses from various leaks before you can get a full charge. I’m amazed it’s lasted as long as it has. I got myself a bulky 2-litre barrel pump (above left, £20) rated at over 11psi. As you can imagine, on a low-volume IK this works fast, not least because it pumps on up and down strokes. Like Bravo foot pumps, it also has a second port to suck out ever last dram of air – handy for compact packing at the end of a tour.

kpumpmini

The Bravo barrel is bulky so I’ve got a K-Pump Mini (right, review here) from i-canoe in Ireland who can import anything from the NRS catalog in the US, and without a huge mark up too (€80 delivered, not sold in the UK). My longer K-Pump 100 worked surprisingly well inflating the Incept; we’ll see how the Mini model performs on the Amigo. If nothing else it will be a handy top-up pump; Grabner cover themselves very comfortably by claiming that anything under a 20% pressure loss over a 24-hour period is not a warranty claim, though I’ve never owned an IK that lost that much air in weeks let alone a day. K-Pumps can’t suck out air like Bravo pumps, but using a loose hose with the bayonet fitting it can be done by lung.

Additional D-rings

ami-dee

Next, I glued on my half-dozen D-rings (left). Front and rear will hold down gear; the other four locate my cut down packraft seat as well as an adjustable footrest tube similar to what I made for the Solar last year. The seat and foot rings will also double up as thigh strap location points.
I’ve not always been that successful at gluing on previous boats, so this time did it by the book: roughen with sandpaper, wipe clean with MEK or alcohol, apply glue to both surfaces thinly and wait half an hour, glue again and wait less, then apply and press down hard with the roller.

ami-poly

Doing this I had a feeling the two-part Polymarine 2990 adhesive (right) was more effective than whatever I used doing the same job on the slipperier PVC-U Incept a year or two ago. I suspect Hypalon/Nitrilon is easier to glue; ‘plastic’ PVC-U is more effectively heat welded.

Thigh straps

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ami-log

Over the years I never really got into using the thigh straps on my Incept or Java – perhaps the need for ruddering the Incept made them more tricky to use, or perhaps I’m just an idle paddler. But with the  Amigo, I want to have that option to help it shift. In any case, it’s worth persevering with thigh straps as this is one of the main things that separates IKs from hardshell kayaks in terms of boat control in rough conditions and optimal torso-centered paddling efficiency. Straps are not quite as effective as bracing your knees under the top deck of a hardshell, but they’re all you can do with an IK. Otherwise, you’re just sitting in a canoe or on a floating log. I’ve now got fully used to the straps on the Amigo and use them without thinking, just like I feel much more secure with the toe clips on my bike’s pedals.

Footrest

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In my opinion, you need some kind of footrest too, if a braced body is to make an efficient paddle sweep – it’s probably more important than thigh braces. Last year I improved this on the old Gumo Solar that’s occasionally used by the g-friend. The Gumotex footrest cushion (same as my old Sunny) was too far away for the 5-foot Mrs to use effectively and is squidgy at best. On the Amigo I was able to use the front thigh strap D-rings to hook up the 4-inch footrest pipe (above left) with an adjustable strap looped through. It works fine.

Seat

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At the other end I’ve separated the toilet-like seat base of my old Alpacka Denali packraft from the backrest section. It clips to the rear thigh strap hardware with mini snaplinks (left). This ultralight seat has already been repaired once by re-heat sealing the flat seam and another hard bounce may pop it again. It’s lasted the summer but if that happens I’ll come up with something better; any inflatable pad or IK seat base will do. The Incept seat was pretty good, so was the firm-backed Feathercraft Java seat which didn’t fold under strain. Right now, at about 50 grams, the cut-down Alpacka seat base is about as light as a kayak seat can be.

The hard plastic Grabner backrest was comfortable enough to lean on once I added a bit of karrimat, though it kept coming adrift from the lug holes when the bar pivoted down, usually when manhandling the boat, but occasionally on the water too. At sea it’s quite awkward to refit the bar into the black rubber lugs as the hull sides push apart. The only way I found was to face backwards in the boat, swing the legs out into the water and squeeze them against the hulls to repeg the seat bar.

To keep the bar in place while retaining a tool-free, quick detach element I hammered out the outer brass peg and replaced it with an R clip (above left). But that didn’t last too long – one clip bent and fell out and, as expected with footrests, the alloy bar was bending against the strain. I tried a blue seat strap instead (right), but hooking that to the rubber seatrest lugs looked like it put too much strain and distort them. Ripping those lugs off would be a pain. No way round it but to glue on another two D-rings as I did on the Solar; a 4.5-inch patch has four or five times the glued surface area of the seatbar lugs so ought to take the strain. D-ring prices seem high so I settled on what I knew – chunky Grabner items at €15 each (right). Grabner deliver fast from Austria.

grabner-D-rings

The seat strap was a crude solution so I figured I may as well try a proper, full-height backrest off an SoT. On ebay the ‘heavy-duty‘ item (left) with long adjustment straps and even a back pocket went for £24 – less than the two D-rings which hold it in place. As far as I can tell the rear straps’ only purpose is to hold the backrest upright, but it’s proved very comfortable – like a proper seat and with no inflation required. I’ll keep the original seat bar for less frequent two-up paddling where I don’t have a footrest to put a strain on it.
So after a couple of months use I have optimised my Amigo by completing the adaptions listed here, making a comfortable and more practical boat for coast hopping and river touring. The cost has been six D-rings £80; seat £24, glue £15, seat base and straps already had; Gumo skeg and patch £24, and two pumps, gauge and adapters £110.

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Grabner Amigo and Medway Canoe Chutes

River status

A sunny day in the south of England saw me back on the water with the Big Kahuna Man  after many months off. It was a chance to anoint my new Grabner Amigo’s slick, factory-oiled hull with the Medway’s occluded discharge. If you’re interested, there’s more on why I got myself an Amigo right here.

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BK Man and I started out of Tonbridge with a plan to replicate our icy winter run of last year when at times we had to crack our way down the river. Assembling the Amigo for the first time was of course simple once I had the bayonet adaptor fitted to the end of my aged Bravo foot pump, but that pump could barely manage to get the requisite 0.3 bar (4.3psi) the Amigo runs. More about all that malarkey on the mods page.

amitownchute

We slipped down the rather tame Tonbridge Town Lock chute (right) where it soon became obvious the Amigo was not going to break any speed records. This may be a false impression as there was a stiff head-breeze, negligible current and my lack of paddling fitness and of course the Amigo’s 3.75m and 80cm width – over half a metre shorter and 11cm or 4.3 inches wider than my old Incept. All that made for hard yakka while the slick Kahuna glided effortlessly by.

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On a positive note the Medway hereabouts now appears to be fully chuted up for canoes – we could have got all the way to Yalding without getting out. As mentioned, some chutes are rather dull affairs where fixed bristles churn up the water and slow a boat down. Others, as we knew well, were steeper and more sporty numbers that you attack at full pelt (left). We like those!

amiportchute

The recently fitted Gumotex skeg tracked flawlessly but still kept the curly ended Amigo turnable. It will be good to try paddling without it; not such a good idea at sea but always handy in shallow rivers where the current should provide the speed you otherwise gain from being able to paddle harder with a skeg.

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In between the fun chutes, the simpering Medway crept by. BK Man combed the water as gently as if he was brushing Kate Middleton’s perfumed hair, while I hacked away like the Barber of Seville with my too-large Corryvreckan paddle; very light and stiff it may be but it’s not the blade of choice when unfit. Also, the boat’s secondary seat lugs tended to catch my thumbs, the spare packraft seat was a bit sloppy on the factory oil and I was in dire need of a footrest: all things to refine or fit once relocated up north.
Later I just rested on the seat back with no air padding from the Alpacka seat and that was fine and enabled a good back posture, though I do worry about snapping that seat bar in a hard hit or clumsy moment. It did dislodge a couple of times as the boat flexed down steeper chutes. I suppose a stick or even just a strap will make do as a replacement.

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You can see from the pic on the right that even with my weight and only .25 bar in the side tubes, the Amigo is as straight as a boiled hardshell and unlike the Sunny of old. In future I’ll pump it up to 0.33 or so to compensate for the cooling once it gets in the water.

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By the time we got to the sporty Sluice Weir Chute (lef and right) I was knackered, sore and starving, a torment made worse by the gusting breeze and the succulent aroma of wild garlic emanating from the lush, green river banks. Southern England in early summer really is a great place to be an insect.

amikinder

We had high hopes of snaring a good feed at Ye Olde Anchor Inn at Yalding, but it was so poor it wasn’t even worth a picture. I ate as well in primary school back in 1968. What a waste of a great location; someone keel-haul the chef! Next time we’ll revert to the tea room on the other bank. As we approached the Inn we were puzzled by a string of schoolkids in mini kayaks lining up to slip down the flat Yalding weir face. Like some neoprene Pied Piper, their teacher or guide was actually pushing away the orange safety booms so the little mites could slip through and potentially plummet to their deaths. I suppose the river police must allow it. At the low levels we knew  the flat slide down the weir face was not so suited to our long boats – the Kahuna’s nose would dig in to the concrete at the base and spin the back around while I’d scrape my skeg all the way down to the sound of melting plastic. Btw, check out this vid of what happens at Yalding when they open the taps. Scary!

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Gastronomically unsatisfied, we lowered ourselves back into our boats for the short hop to Hampstead Lock (no chute). Here, in the full spirit of The Pack Boating Way, we dismantled our boats, walked 5 minutes the station and caught the train back to Tonbridge. I can confide that like a Sunny, an Amigo is so easy to dry, just splay it out (right) like a Peruvian hamster entree, give it a wipe, roll it up and off you go.

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One thing I can to say about the Grabner – you do appear to get what you pay for. Construction appears to be flawless – far superior to the Incept, better than Gumoes I’ve had and with not a smudge of stray glue or ill-adhered creases, gaps or lumps. Once the set up is optimised it’s an IK that ought to last many, many years. More Amigo action to come up in the Summer Isles in the next couple of months