SPI Epoxy adhesion problems

shine said:
how thick is the epoxy ? 1 coat or 2? thin fresh epoxy can be attacked by polyester filler or poly primer.
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I spray all panels with W400 1.4. with 2 med-wet coats. Not sure how long these cured before filler began. Sometimes 2 or 3 days but usually several weeks.

The first peeler we noticed was on an A-pillar that had no bodywork. Several weeks passed before the body was ready for primer. We masked the pillar with tape and the tape pulled the epoxy off.
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All this can be is a flaw in the metal cleaning stage. At my shop, all we do is wipe sanded areas down with SPI #700, using prep wipes dedicated for that purpose. #710 can be used in addition to #700, but we've found it to be unnecessary (in our environment). I have to say that after over a decade of using the epoxy and experimenting with different cleaning methods, a gallon of #700 should just be sold in a kit with any epoxy/activator to those who are first using it. It's all that's really necessary at the cleaning stage.
 
If you put filler over the epoxytoo soon before the "window" the epoxy will lose adhesion as well. But 99% certain the evaporust is the cause. That and like others said your panel looks shiny like you haven't got good 80 git DA scratches on there. It's not the product it's on your end.
 
If you hit any of those areas with a wire wheel after sanding that could be an issue too, a wire wheel on a drill or high speed tool can polish the metal removing the tooth from 80grt scratches which in turn can cause loss of adhesion. Not knowing what all steps were taken and done these are only assumptions that we know have been problems but there was something done before the epoxy was applied that has caused it.
 
DATEC said:
If you hit any of those areas with a wire wheel after sanding that could be an issue too, a wire wheel on a drill or high speed tool can polish the metal removing the tooth from 80grt scratches which in turn can cause loss of adhesion. Not knowing what all steps were taken and done these are only assumptions that we know have been problems but there was something done before the epoxy was applied that has caused it.
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What about those black 3m strip disc? Those leave aggressive marks.
 
Clean & Strip discs can leave a film that must be sanded off, I have personally seen adhesion loss by failing to do this step. I think it might be smeared melted plastic, not sure though.
 
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Agree with Crash, absolutely no powered scuff discs of any kind.. You will have an issue sooner or later. This is not a job you want or can be lazy on we all do a lot of hard on your body sanding. The one thing that every body man has that has been doing this for any length of time is a lack of finger prints we use our hands and fingers alot.

Is that what was Used?
 
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