Repairing a Gumotex Seawave

lm-pumperThe other day, while lashing the Gumotex drybag backpack to a chopped-down trolley I foolishly wore two holes in my Seawave ;-((
Pumping away like a donkey on Limehouse jetty (above), I assumed the non-standard PRV was playing up; probably a grain of Achnahaird sand stuck on the seal. I flipped the cap off, tried to clean it out by springing the valve from behind but no luck. So I gave up and was ready to dismantle or replace it later.
It was only when sw-holesfrustratedly rolling up the boat I noticed two small ragged holes in the hull and realised what had happened. With half a paddle shoved into the cinched-up bag to make a handle, and it all lashed in a to the trolley, I thought I was being rather clever and minimalistic. But strapped to the trolley, the pack soon sagged under its weight and rubbed on the sharp edge of the hard plastic wheels which wore through the pack and then the boat’s hull.
The cut-down trolley had worked fine with my UDB drybag in New Zealand (left), but that was partly because you can fully inflate a UDB via its unique one-way oral valve, transforming it  from saggy sack to firm sausage.
Ironically, just two days before this happened, I’d snagged a BNWT Orlieb RS140 (right) cheap on ebay. I’d been eyeing up this non-rigid wheeler duffle as a versatile Seawave transporter plus reliable on-water drybag/buoyancy aid (review shortly).
And what’s more, inventing the wheel was all very well but to be honest, for short 10-minute spells of urban pavement walking between trains and buses (as opposed to traversing Scottish glens), the 17-kilo Seawave is not so hard to carry as a backpack. Lesson quickly learned.


With enough practice with D-rings, let along bike punctures over the years, I was confident I could do a bomb-proof repair on the Seawave. In a way, I was even a little chuffed that my 5-year old kayak was earning its first battle scars. Plus, in my experience rubber-based IKs like Gumotex, NRS and Grabner glue more reliably than PVC boats. Shiny packraft TPU is even easier: you can just tape it, but packrafts are low-psi boats not normally inflated with mechanical pumps. My adapted Seawave side tubes run 4 or 5 psi.

ami-polyThings you will need

  • Patch
  • The right two-part glue (right)
  • Solvent and rag
  • Sandpaper or abrasive foam sanding block
  • Masking tape
  • Small brush
  • Tyre repair roller (right)
  • Space to do a good job

 

STEP 1 • Match up a patch from your collection, ideally identical fabric. For a small hole extend the patch at least an inch.

STEP 2 • Clean the punctured area and patch surface with solvent and wipe dry. This time all I had was brake cleaner spray, but ordered some toluene for next time.

STEP 3 • Sand down the two surfaces and then clean and wipe again with solvent. Avoid touching these cleaned surfaces with your fingers.

Some colour coming off is a good sign you’ve removed any sheen or patina.

STEP 4 • Position the unglued patch and mask the perimeter with tape to avoid excess residue and to help with positioning. If the patch is not perfectly symmetrical (like above) mark it – but make it bold – I still got it wrong!

STEP 5 • Mix up some two-part Hypalon (Nitrilon; EDPM) glue. It’s rare than one-part glue works as well, but Aquaseal has worked for me, gluing a skeg-patch to a Grabner.

I found some mini brushlettes in my repair kit box – they must have come free with some glue.

STEP 6 • Brush on the glue thinly to the two surfaces. With Polymarine you then to wait 30 mins for it to cure/dry, then apply another coat and wait till touch dry (5-10 mins). Here’s their full guide: http://www.polymarine.com/advice/hypalon-adhesive-how-to-repair-inflatable-boat-tubes

You can see I made typical errors: mixed up too much glue (but better too much than not enough)…

… and applied too much glue on the patch…

… but a just-right thin later on the hull.

STEP 7 • With the deflated boat repair positioned on a firm surface like a hard floor or better still, draped over a wooden stool, carefully lay the glued patch over the damaged area…

… then – STEP 8 • peel off the masking tape and ROLL DOWN HARD moving from one edge to the other and again at 90° and again diagonally with your Baltic pine-handled roller, making sure the edges have stuck down. It won’t hurt to roll again in 20 minutes and again after an hour to make sure the two parts have well and truly bonded till death do them part. And actually, only about 25% of the glue was wasted.

In 12 hours the repair is cured and ought to last the life of the boat. Never do that trolley thing again!

 

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