Automotive fiberglass and resin for a sailboat?

[clodgo]

Hello,

Just a quick question...

Do I have to spend lots of money on special boat resin and cloth or can I get away with the stuff you can buy at a regular hardware store?

I'm just getting the bottom on my boat and I'd hate to mess it all up now.

Any thoughts would be appreciated.

Chris

[Knut Sand]

Wood or GRP? Polyester, vinylester or epoxy?
Is it for repair or newbuild?

For wood, epoxy is normally the best, use wowen glass fibre cloth, not too thick. (painted finish or "varnished"(?)).

GRP, sail boat.... keel area.... stressed areas, careful with automotive things.... Short threaded glass isnt as stong as woven mats. (Check the thread "keels and keels again").

Added; there are reasonably priced solutions to all of that out there, doesnt have to spend a fortune.... well; depending on the surfaces of the boat, that is....

[kach22i]

It's difficult to get the mix just right with automotive polyester, and it melts through rigid insulation foam board.

I like the epoxy pump system by "West", but recently picked up a similar product from here:

http://www.slipstreamhover.com/?Click=1069

[Herman]

Funny thing is that at least here the automotive stuff is way more expensive then the regular polyester and mat.

Contact a wholesaler, who can either sell materials to you, or can redirect you to a shop that has the right stuff in the right quantities.

And make sure you order the material you really want to have. Pricewise, woven roving is about the same price as mat, but stronger. (alternate with mat when hand laminating). For resin, epoxy is a better choice for wood.
Polyester resin is more brittle, but also cheaper then epoxy. The majority of boats are polyester, although DIY builders tend to choose epoxy.

[kach22i]

Originally Posted by Herman

although DIY builders tend to choose epoxy.

Fewer fumes, works lasts longer and is stronger.

When you do it yourself, you don't want to do it over and over again.

I like that I can add the black carbon/graphite and get a slippery surface. I think you can add sand and get a non-slip surface as well. I'm not sure you can do either with polyester.

I've played with micro fillers / micro balloons and epoxy before, lots of fun experimenting.

[Herman]

You could do the same with polyester, but indeed epoxy is many times more versatile. Although it has its limitations, primarily in UV stability.

[kach22i]

Originally Posted by Herman

epoxy........limitations, primarily in UV stability.

I did not know this, I'll be looking it up now.

[clodgo]

Thanks for your responses,

Doing the woodwork is one thing, making it float is another.

I've been using epoxy with woven fiberglass cloth over plywood. So far I've concentrated on the interior and the glass makes the boat super strong without the bottom on it. I'm waiting until spring to glass the bottom outdoors.

I have mixed graphite with epoxy and it works great. on this project I've been filling gaps on the interior with epoxy mixed with sawdust. In certain places I would then cover the joint with resin and cloth. so far so good.

I will check out the Resin Infusion Forum. Thanks again,

Chris