DP 50 epoxy problem

[Tscott38]

I've just finished(almost) all my primer work and then decided to swap out my windshield.  I figured it would be easy. I had no rust issues and stripped the windshield channel down to bare steel just as I has done earlier with the entire car.  I had a little bit of  dp50lf left and mixed up a small bit of it let if wait 30 minutes and brushed on two coats waiting an hour or so between. The next day I go in and wipe a little lacquer thinner over one part of it cause it was a little rough and a couple swipes takes the epoxy off.  I am horrified.  I just did the whole car with this stuff.  What's different is I never touched anything with laqcuer thinner so soon before.  Also I might have been off with my mix ratios since I'm painting such a small amount- like half an ounce.  What could have happened ?  Other places on the car I have wiped lacquer thinner on and the epoxy is on there and won't come off. 

[hemi-hampton]

Lacquer thinner is much stronger then enamel reducer or most other solvents & typically will remove paint or other solvents. If to fresh & not hard will remove more easily. Why did you wipe a rough spot with thinner, what were you planning on doing by wiping with thinner?

[Tscott38]

since it was a small area and I had brushed it on, it had some dirt/sand/contaminants  on it in one isolated spot.  I thought I could knock that out with the Lacquer thinner.  If you rub Lacquer thinner over this stuff a lot, it does wear it off - have done this if I had a small drip or overspray elsewhere.  I was shocked that it came off so easily this time though and thought that my catalyst had gone bad, or that i had the ratio way off.  I was measuring this stuff out by the drop, not in a measured container and thought that may be a problem as the DP50 is thick and the DP401 is thin and I could have been off.  I am down to my last 10 drops of catalyst and my last half ounce of DP50. I didnt want to buy another quart to do a few square inches of  surface.  Thank you for the reply.   

[73rallye440magnum]

I have experience with a few different paint systems and although I will say PPG epoxy is my least favorite, I'll repeat hemi-Hampton and reiterate that lacquer thinner is a very aggressive solvent. Your epoxy was not even close to cured.

No big deal, touch up any bare metal spots again.

[hemi-hampton]

Get a air blower & blow the area out good with compressed air, or use a male/female air fitting screwed together (my preferred method) and blow out to remove debris then use Wax & Grease remove to remove contaminents. Then your good to go with no problems. Unless you don't have a compressor or blower or wax & grease remover, then your likely to run into problems. LEON.

[Patronus]

Did you forget any hardener? (I dont use DP50) Is it 2 or 3 parts?

[Tscott38]

Thanks everyone for the ideas.  Does anyone think mixing the epoxy and the catalyst has to be exact or not curing could happen?  That was my fear.

[hemi-hampton]

Did you ise the 401 or 402 Hardener. The 401 needs a 30 minute permeation period. Where you stir it & let it sit for 30 minutes before you use it. I prefer the 402 myself as there is no waiting. LEON.

[Tscott38]

I had run out of my 401 so I found an old can of 402 I had around for a few years.   It was amber colored. Don't know if it was bad or not.  Regardless I wiped it all off bought a new pint of 401 waited 30 minutes and redid it.  I left it alone this time for 3 days and it's fine now.  Thanks for the help. 

[hemi-hampton]

Any Hardener is notorious for going bad quick if the top is not screwed on very tight. Any air or moisture in the hardener will ruin it. LEON.