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Re: Epoxy: Working with Marine Grade Epoxy
By:ChrisO
Date: 12/23/2003, 10:01 pm

Grant,

I looked at your project photos and have the following comments. I'll embed them in your question list below.

: #1 Fish Eye's.

From what I can see, you are not getting what are commonly referred to as fish eyes. It looks more to me as if your resin is not completely filling the weave and the resultant hole is telegraphing through the finish. You can put on some drops of epoxy to fill these areas or continue to apply another fill coat and then carefully sand back to get the whole surface smooth.

If you are, in fact, getting fish eyes, it's because of some type of contaminant on the surface of the carbon that is repelling the epoxy. Because this is a cosmetic product, I'd get back to the cloth by removing the epoxy, wash the surface (see below for amine blush) wipe it down with acetone and start over with the epoxy fill prior to a UV finish coat.

: #2 Spots in the clear resin.

These could be caused by impurities in your mix from the epoxy or the hardener or perhaps something that has fallen onto the resin during the cure period.

: #3 Long dry times.

That area that you called cancerous near the edge of your object could be caused by epoxy/hardener that has not been thoroughly mixed prior to application. The epoxy will not cure if that is so and you'll have to wipe it off with acetone, sand gently and re-apply the epoxy to float a good coat.

: #4 The resin has a weird greesey finish?

It could be that your cured epoxy has what is called amine blush. If so, just wash the part with a soft rag and water with a small quantity of gentle soap.

Beyond all this, my experience with carbon parts and getting a good, "holographic", type of finish would indicate that you use a clear urethane finish over the top of the epoxy. This does several things. It provides some measure of UV protection for the carbon, though this isn't truly important to this project as you're not depending upon the cloth for anything more than cosmetics.

Next, it allows a controlled, fine spray to establish the finish coat quality rather than any more dificult method you may be using to apply the epoxy.

Last, the urethane spray is easier to work with. You can get several coats on the part in one day, unlike epoxy. It's easier to sand to a fine finish between coats with progressively finer paper and will produce a dazzling finish with depth and a nasty look that you're after with this part.

I've used Benjamin Moore clear urethane, any number of commercial spray can products that you can get from a good paint department and for the most wow surface finish, Dupont's two part auto finish, Imron. Imron is nasty stuff, and EXPENSIVE.

If you front for Imron, wear every form of protective gear you can beg borrow or swipe to get on your person before spraying. Guys who spray cars for a living who did not see fit to wear heavy duty protective gear are now very much of the mentally defective category.The correct gear includes: full coverage clothing, gloves and the best, full face, positive pressure respirator possible. No kidding. http://www.bronkalla.com/upkeep/spray_imron.htm

Imron contains isocyanates which are as nasty as a chemical can get and still be sold.

My advice is to use the simple spray stuff from the $4 spray can and observe the rules on the can. Simple.

Chris

Messages In This Thread

Epoxy: Working with Marine Grade Epoxy
grant -- 12/23/2003, 8:25 pm
Re: Epoxy: Working with Marine Grade Epoxy
grant -- 12/24/2003, 2:26 am
Re: Epoxy: Working with Marine Grade Epoxy
KenC -- 12/24/2003, 7:39 am
Re: Epoxy: Working with Marine Grade Epoxy
grant -- 12/24/2003, 7:34 pm
Re: Epoxy: Working with Marine Grade Epoxy
Paul G. Jacobson -- 12/25/2003, 12:11 am
Re: Epoxy: Working with Marine Grade Epoxy
Paul G. Jacobson -- 12/23/2003, 11:34 pm
Re: Epoxy: Working with Marine Grade Epoxy
ChrisO -- 12/23/2003, 10:01 pm
Re: Epoxy: Working with Marine Grade Epoxy *LINK*
srchr/gerald -- 12/23/2003, 9:39 pm
Re: Epoxy: Working with Marine Grade Epoxy
Chip Sandresky -- 12/23/2003, 9:25 pm
Re: Epoxy: Working with Marine Grade Epoxy
grant -- 12/30/2003, 3:41 pm