Repair advice for a Twintec polypropylene hull

[MikeL]

I need some help before I sped a lot of money - I am after some repair advice for a boat with a Twintec hull.

Twintec is a polypropylene and glassfibre composite similar to fibreglass but with polypropylene (plastic) instead of epoxy resin.

The boat has been left out in the sun for several years and all the exposed surfaces have degrade to the extent that the glassfibre is exposed. Very itchy!

Halmatic have informed me that the only way to fix this is to send the boat to them to be "baked" at a cost of £4000!

I was after a way to coat the twintec to seal in the fibres - Halmatic have have said that because it is plastic nothing will bond with it e.g. if we painted on an epoxy gelcoat it would just come off?

I have heard that a vinyl paint might do the trick - I was hoping that someone on this forum might have a better idea?

The boat is structurally sound we just need to seal the outer surface to stop the itching.

Mike

[Poly]

Polyprop is a bugger to get stuff to stick to, but there are paints around specific for it. I have a polyethylene (rotomolded) boat and it if gets scratched they suggest sanding it (wet and dry) and then a hot air gun to restore the lustre - i've not tried it so can't say if its easy or not, and no idea if that would work for your needs.

I would try the folks who make Twintek to see if they can advise? http://www.ocvreinforcements.com/solutions/Twintex.asp

[codprawn]

If you are getting the boat for next to nothing go for it - otherwise don't bother.

How much fibreglass is exposed? Not much will stick to the plastic but if it's sanded down enough it may be different.

Another option is to iron it - seriously use something hot to melt it and smooth it over.

[Tim M]

Originally Posted by Polwart

I have a polyethylene (rotomolded) boat and it if gets scratched they suggest sanding it (wet and dry) and then a hot air gun to restore the lustre - i've not tried it so can't say if its easy or not, and no idea if that would work for your needs.

I've got one too which gets used and abused - I'll give that a go, sounds like it might work

[MikeL]

Cheers guys thats great,

Mike

[jyasaki]

There are some epoxies/adhesives out now that will stick to Polypro.

If you're just trying to coat the exposed fiberglass, this would probably be the way to go (or use normal epoxy, and just hit the glass areas; i.e. don't worry about bonding to the PP.)

The only problem is the Polypropylene bonding epoxies are damned expensive.

3M Scotchweld DP-8005 is one, but is priced at around $20 - 30 US for a 35ml cartridge (you'll most likely want the mixing applicator and nozzles as well.)

I think Loctite and some other brands have similar stuff out, but read the application notes first; some require pretreatment (usually flame treatment) of the plastic to be bonded.


jky