Aeropoxy Light Problems

rv6ejguy · #1 06-22-2007, 10:04 AM

I just got some AeroPoxy Light filler from ACS last week on the advice of another experienced RV builder nearby. I mixed according to instructions and applied to my cabin top to fill a couple of small depressions. The stuff never cured and was like rubber. I peeled it off with a razor blade.

Last night, I vigorously stirred both cans mixed using a digital scale and this morning was rewarded with more rubbery mix on a test sample.

Is this stuff really critical on the ratio or do I have a bad batch?

lostpilot28 · #2 06-22-2007, 10:44 AM

Their website says that the 2:1 ratio is not critical, but I'm guessing it should be close. The cans I have are over 2 years old and I am using it this week to close my elevator tips. It's been hot here lately (over 90 F) and I had about 10 minutes working time on the last batch 2 days ago! Guess I'll avoid late afternoons when using this stuff.

Just for reference, I bought it to work on a fiberglass airplane I used to own. I once used it on a cool, rainy day and it took forever to harden. I think the temps were around 55 F.

By the way: when it hardens it still looks uncured (imho)...it's kind of shiny, but when it's cured it sands well. It should only take a few hours to fully cure if it's hot and dry.

rv6ejguy · #3 06-22-2007, 11:10 AM

It's been 85-90F here the last few days but fairly humid. Even after 24 hours it was like rubber. hmmm...

N8RV · #4 10-21-2008, 10:54 AM

Same here. When I first applied some a few weeks ago, it was 70-80 degrees and it took DAYS for it to set. The temps are now into the 50s-60s and the AeroPoxy that I smeared on a WEEK ago is still rubbery! I threw the stuff away. Guess I'll stick with West epoxy and microballoons.

rv6ejguy · #5 10-21-2008, 11:49 AM

I talked to Aeropoxy directly last year about the problems I had and they were extremely helpful. They checked lot numbers and mixed up a sample of those and it cured fine. Despite this, they sent me 2 brand new cans with new lot numbers, plus 2 cans of casting resin which we use in the EFI business to pot components at no charge.

Second batch was a champ and this stuffs sands really nicely and it super lightweight. I used lots on my RV10 windshield transition.

These guys stepped up to the plate and made it all right for me. Top notch service.

Never tried mixing any more of the old batch. On the new batch, I always used a digital scale to measure out the two parts. It may be quite critical in that regard. The first times, I was eyeballing quantities so it could have been my fault totally.

West with MB is nasty to sand compared to the Aeropoxy filler. I found this out the hard way.