Two More Epoxy Questions??

General Discussion
1

  1. To insure complete saturation can you brush on epoxy resin directly on the sealed foam then take your cloth that’s rolled on a hard cardboard tube, start on one end and just roll it down the board?

  2. Greg says when using additive F that “It also doesn’t interfere with recoating as wax solution in polyester does. That means no sanding between layers.” Does that mean after a hotcoat, sand it for smoothness, then apply another as a “gloss coat” If this “gloss coat” comes out perfect smoothness-wise but has a few pinholes, can I brush on another epoxy coat without any sanding??

2

  1. might have some problems getting the cloth to lay exactly where you want it on a wet blank. give it a try and report back…but RR is so easy to wet out, i just stick with the old fashioned way.

  2. when you hotcoat with poly, wax rises to the top so that it is sandable. however, if you don’t sand it before glosscoating, it won’t bond because you aren’t laying the gloss over the resin…it’s on the wax! with RR, because it never cures tacky (it’s always sandable), there is no need for wax, so you can go straight from one coat to the next without sanding. although, it’s best to hotcoat the board, and then sand it totally flat, and then lay on a thin glosscoat. you can thin out the gloss with a little denatured alcohol, and this will help it to lay flatter, and reduce pinholes (the denatured alcohol, because it’s less dense than the resin, will rise to the top as it cures, and then just evaporate).

3

Hey soulstice how much denatured alchohol do you use per batch of gloss coat?

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Hi 220 -

Regarding second question… Instructions for RR (and other epoxies in general) is to use above 65 degrees. If you follow those directions and use additive F you should be able to recoat without sanding but don’t wait too long. I’ve had bonding issues between coats but it got cold and according to Greg this may lead to blush issues even with RR and additive F. If you want to play it safe, I have also received recommendations from a professional epoxy glasser to alcohol wipe and sand between coats.

5

What is the ‘denatured alcohol’ that you get?

Here in Canada, I can get methyl hydrate or isopropyl alcohol (rubbing).

Would it make a difference?

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One “trick” I made up from reading some stuff on here. I just use a 3" throw away brush for ever thing. When it comes to the rails, instead of trying to get it to run down, or instead of flipping up the cloth, wetting, then laying it down ( I came up w/this trick when I was going to flip up the glass, using the brush for a second and realized…) I just lift the glass and brush the blank pretty thick, then as I brush the glass… it wets out so fast… Said it before, I love RR epoxy. Taylor

7

In answer to the first question, it is quite acceptible to wet out the foam first, your cloth will wet out much quicker.

two points though

1 if the cloth doesn’t roll out where you want first time it is a bitch to move, so you may want to leave the laps over long, the main advantage is that once it is down it won’t move around with the brush/ roller before it is stuck down.

2 I always use a 4" mohair roller instead of a brush, if you don’t get too excited the epoxy won’t froth.

8

eh…i just go by feel…a cap full…maybe two.

also, i’m in south florida…so it’s always warm, here. if your resin is thick due to coldness, be sure to heat it up first.

9

denatured alcohol (i think) is 95% rubbing alcohol and 5% wood alcohol. i’m not sure the wood alcohol serves any real purpose besides making it poison, so that alcoholics won’t go to their local home improvement store, buy a gallon of denatured alcohol for $8 and then go get sloppy on it.

can anyone either confirm or deny this??

10

here’s a good link on thinning epoxy resins.http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

Johan1: the methyl hydrate is commonly used as a laquer thinner and an airbrake antifreeze for large trucks. read the labels carefully as a petroleum oil is sometimes added in order to lubricate the rubber seals on air systems. I don’t imagine epoxy and oil agree with each other. As far as isopropanal, get the good stuff they keep behind the counter (In BC we have to fill out paper work and provide ID as its used in meth labs!). Well worth the hassle as its 99.9% pure.