Delta 16 or Seaward Cosma / Repairing Thermoform kayaks

[pryaker]

Re: Delta 16 or Seaward Cosma Thermoform?

I'll be interested in what Alder Creek has to say.


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Well Dave they didn't really have much to say other than it would work. I was too late to get to talk to the rep whose blog the repair video came from, but the video sure makes it seem easy to repair TF boats.

I believe thermoformed boats are based on polycarbonate, which is tougher and far less UV sensitove than PMMA. A link: http://en.wikipedia.org/wiki/Polycarbonate

Doing a bit of searching on Eddyline's site I found that their plastic is a laminate of ABS and acrylic and that they admit it probably won't last as long as fiberglass composite but that it's a good option for a lower price.

As far as using the plastic weld for quickie repairs to resin composites with a little hindsight I'd think that 5 minute epoxy might be better? Just seems that epoxy must be stronger in a mechanical bond than the devcon which is made to be a chemical bond (weld) unless of course the devcon can 'weld' the resins- but I doubt if it can...

like you I'm a bit out of my league here. Mostly just parroting info...

 

[johnd]

Re: Delta 16 or Seaward Cosma Thermoform?

pdx,

I'll be interested in what Alder Creek has to say.

Methyl methacrylate is the monomer on which polymethyl methacrylate is based (= PMMA = Plexiglas = Lucite = "acrylic" at places like TAP Plastics). A link: http://en.wikipedia.org/wiki/Poly(methyl_methacrylate)

I believe thermoformed boats are based on polycarbonate, which is tougher and far less UV sensitove than PMMA. A link: http://en.wikipedia.org/wiki/Polycarbonate

I think the need for methyl methacrylate in the PlasticWelder stuff is to to a little dissolving of the polycarbonate to assist in forming a mechanical bond to hold things together. But, I'm over my head here.

It might be good for the moderators to shift this discussion over to a new topic, something like "Repairing Thermoformed Boats," as the issue is not limited to either Delta's products or Seaward's boats. And, it might drag in some folks who know more, and can flesh out things. If thermoformed boats are that easy to fix, and the fixes are permanent, my prejudice against them will pretty much disappear.

I had an Eddyline nighthawk in which the cockpit coaming was partially detached from the hull. Eddlyline sent me a tube of the Devcon Plastic welder ( with the methacrylate ) . It made a totally permanent bond. This is basically the same stuff they use to " weld" any of the parts together. Thermoform holds up to UV better than poly and doesn't scratch as easily, but it won't last as long as poly stored properly or as long as fiberglass. I also had a Seaward chinook that developed a crack from a glancing blow that would not have cracked fiberglass or poly . And I know of a delta 18 that basically folded in big wave. Thermoform stays shiny longer, but is just not as tough. The hulls generally have much more flex than other materials. Thermoform is just not as rugged as other materials, and the the integrity of the boat will depend on how the manufacturer has incorporated stiffeners into the design.