Hey guys, I got a few questions about my epoxy board. It’s all complete and if you close your eyes, and feel it, it feels like a new kick ass board, but… the looks are different. The glass came out milky, I’ve heard that this is from humidity in the air, but living in florida and working in a garage, how do I take care of this. The next question is when I sanded the board, I got tons of really little holes, like really small, did I lay the coat on too thick, was it too cold or what? And just one more easy question for you guys, is denatured alcohol the same as isopropal alcohol? Can I thin down epoxy with isopropal for thin coating purposes? Thanks guys, this actually means alot to me, thanks - Phinnie
maybe you could try a dehumidifier in your garage
as far as the little holes
is that just gaps in the weave
you could try a tighter weave cloth
i find 6 oz pretty hard to fill
or i just squeegee in a thinned coat of resin so it pushes into the holes
the other thing is that eps wants to expand as it heats up so its best to glass in falling temperature
just a few suggestions that might help
though i often break my own rules
Hey Phinnie, another thing (aside from humidity) that can cause the milky look is overworking the resin. If you end up pushing it around to much it gets really frothy and all the bubbles can end up leaving it milky looking (see the picture below). It’s really easy to have it happen especially on the laps. Basically try and use minimal strokes and let it work itself into the cloth.
Hey Phinnie,
I think that the tiny little holes are probably pin holes; caused by air blowing out through the curing epoxy. As silly mentioned, lamming in falling temps will stop that. Or many here use a ‘cheater’ coat of epoxy. A light coat squeegeed on an hour os so after you have done the lam, before the hotcoat.
I think any alcohol could be used to thin out the epoxy. Here in Canada there is nothing on the shelves called ‘de-natured alcohol’, so I use methyl hydrate. Just don’t use too much. I put in about as much as I put additive ‘F’ in, for use with resin research epoxy.
For the milkyness, I think chachi nailed it. I have a few boards that came out looking very similar to the one chachi showed.
Phinnie,
Do not use rubbing alcohol, as it is only 70% isopropyl, the balance usually being water. Pure isopropyl is hard to find (at least where I live). Denatured alcohol is found in hardware stores, near the paint chemicals/thinners. It is just ethyl alcohol with some methyl alcohol thrown in so that you can’t drink it without going blind; it keeps hardware stores from having to buy liquor licenses…
If the holes you are talking about are very tiny after sanding (like smaller than 0.1 mm), then they may be due to bubbles in the hotcoat from some overzealous stirring or brushing. I first discovered them on top of a black resin panel in a gloss coat, and as I was using rubbing compound to shine up the finish, the rubbing compound would get into the small holes and so the black panel became ‘milky’ due to the tiny holes. Stirring slowly wll prevent some bubbles and, if you can, hitting the mixture with some vacuum will draw the bubbles out. I also heat my resin for hotcoats and gloss coats so that bubbles rise out faster. I also run a heat gun over the coat after I finish brushing to pop any residual bubbles that I caused due to my poor brushing technique.
I no longer use cheater coats, but they were very useful for filling in laps that were pulled very tight, especially on 6 oz glass.
I still can’t make my laps turn out clear/not milky, so my artwork/graphics are done on top of the hotcoat.
So, to summarize:
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Heat your resin for hot/gloss coats
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Stir slowly
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Use denatured alcohol to thin the epoxy (I do not use more than 1cc per fl. oz of resin)
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Use the heat gun
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Put vacuum on the mixed resin (I use a Mityvac brake bleeder hand vacuum pump to do this)
Hope this helps,
JSS
milky resin is most likely from overworking it. a light touch goes a long way, and you’re always better off to mix up a little more if you’re running thin than to try and squeeze more resin out of the already-saturated glass. also, if you pull the lam too dry, it will lead to hotcoat problems. a cheater coat after the lam helps to prevent that. and always lay your coats on in falling temperatures. outgassing will leave it covered with air bubbles. if you have a heat gun, keep it handy. a quick shot of that will bring any bubbles right up to the surface. heating the resin is the best thing you can do for your glassing. everything will flow real smooth. a small shot of denatured alcohol will also help it to lay real flat, and thereby minimize your sanding efforts. get denatured alcohol. it costs $6 and is available at any hardware store. this is not the stage in board construction to be cutting corners.
Hey Phinie,
If you have pin holes they might very well go all the way to the foam and your board might not be waterproof (how do I know this?). If that’s the case you can fill them with marine putty and paint the board. If you do paint it’s a good idea to use an epoxy primer and top coat with a linear polyurethane like Dupont Imron. PB (Pre-Bert) I used to paint all my boards.