GLassed inside of hull - is one coat enough?

[Erik]

well, i just finished fiberglassing the inside, with just enough epoxy to put one coat on. I assume the reason i have run short is the 4 full exterior coats. So since i am very very pleased with the job on the interior, is one coat strong enough?

this boat is a lake tripper, i will not be using it on any rough rivers at all. weight is not such an issue for me (what can one coat add anyway?), and a non-slip surface is very important for me (i have a 1 and a 3 1/2 year old daughters so i figure the grippier the surface the better.)

Thanks!

[Glen Smith]

If you did a precoat of epoxy on the bare wood then added the glass and one coat of epoxy it might be ok. If all you have is the glass over the bare wood and one wet-out coat of epoxy, I doubt it will be enough. There are often little "pinholes" in the epoxy and water can eventually penetrate. I would add one more coat of epoxy. Pour it right into the hull, spread it around with the squeegee then remove all the excess with the squeegee. This will better seal the first epoxy coat and it will still have some non-slip properties.

[Erik]

Ok, thanks Glen. I am wondering if epoxy is sold in smaller quanities than the larger containers i have been working with. how much epoxy should i buy to finish the boat (one interior coat, plus sealing & attaching gunnels and gluing up seats etc...)

Thanks!!

[Glen Smith]

I know that Lee Valley sell West 105/207 in a 1 quart size. Since it will be a while before you can apply the second coat of epoxy, you should lightly hand-sand the previous coat with 120 grit paper to obtain a mechanical bond.

[hoz]

I have read that the strength of a laminate depends on 3 coats. Based on that one coat is insufficent if you are concerned about flexing, breaking or delamination..

I use 2 coats on the interior of my canoes.

[Tommy]

Noah's Marine sells small bottles of epoxy. I know they have MAS and West in various size bottles.

[Doug]

May be of interest,
http://www.greenval.com/FAQglassinside.html


Doug

[Erik]

So how long do i really have to wait to put the next coat on? tomorow will be 4 days.

[hoz]

At four days it has probably cured too much for a chemical bond. You will have to give it a light scratching with 80 grit then clean dust with acetone rag before coating. You can apply anytime now.

For chemica lbond it should be while the poxy is still "green". Just after it starts to set up. Every epoxy and build is differentbut could be from 1 to 4 hrs. .

[bcscoresby]

I have two layers on my canoe and it’s coming time to varnish. All the recommendations say to sand to Get a mechanical bond between varnish and epoxy. On the inside I still have a textured surface because I didn’t do the third layer to completely fill the texture as recommended in canoecraft. When I read about varnishing they say to sand to get a good mechanical bond. Obviously with the textured surface I’m only going to get the high points. Has anyone had any trouble with varnish separating due to lack of mechanical bond? Do you use something other than sanding to rough the low spots in the texture? Just want to check before I go ahead and make sure I’m not setting myself up for problems.

[sedges]

I have always used a brass bristled brush. You can buy them at the grocery store in the dishwashing utensil section. Clean the brush good with ammonia before using it. The bristles are likely coated with something to prevent oxidation so they are nice and shiny in the store.

You really don't want to sand through the high points and expose the glass. Another issue is making sure it is clean of any thing the epoxy leaves on the surface. That is easy on a smooth surface, but takes a brush to get a textured surface clean.

[Cruiser]

Heya BC ... I had the same question on my first build.

Since you already have a textured inside surface, a light go over with a 220 sandpaper is enough. You want to knock down any sharp points and lightly rough the surface .... out of all the sanding you have done on the boat so far, this should be about the easiest.


Brian