What causes primer to peal and lift right off. The surface was super clean, wiped with acetone and dried. primer was an acrylic 50/50 lacquer thinner.

 

There are many potential reasons....
Lacquer cannot be applied over enamel (but enamel can be applied over lacquer)
Incompatibility (Acetone or other paint residual- even particulate)
Exposed to heat (too hot will make it peel)
Moisture/unseen contamination

 

nice try, look at the pics, primer is over bare metal.

Unfortunately, can't see the pics...........

Over bare metal....definitely contamination issue....even with the primer itself but I will also say, IMHO, lacquer primer is (as compared to the modern primers) sensitive.

IMHO, I would visit a local auto body paint supplier, they do sell rattle can 2 part primer that is really pretty good (if you do not have a spray gun)....an epoxy primer is really the best thing you can use to spray on bare metal...it prevents rust and you can apply filler, etc right over it for very good, strong adhension

 

I'm not the most savvy person when it comes to all of the different kinds of paints and primers but I will tell you what happened to me last spring.

Bought a quart of 2k primer and activator from O'Reilly's. Metal was super clean, wiped down and let flash. Sprayed the primer. Noticed some black in my spray gun container. Brand new spray gun, never been used. Two days later the primer appeared dry but would peal off with a fingernail. Waited a few days more but still wouldn't stick. Took the primer back and the guy behind the counter said there was some kind of contaminate in it. No Sheet! There was no way that anything could have got in the can as I poured it directly into my mixing cup and put the lid back on tight. I wanted them to send it back to the company for an analysis but they didn't. Wouldn't refund my money. They lost a customer. Been buying my primer from Eastwoods and it works great. Screw these local parts houses.

Kenn

 

Kenn, many of your 2K primers are not direct to metal (DTM) application. They need an etch or epoxy under them to "bite" the bare metal surface. This may be the cause of your adhesion issue. The 2K is more of a high build primer to help correct any defects, but few if any will tolerate/adhere to bare metal.. Next, you say the panel was wiped down and let flash. This is incorrect method of cleaning the panel, as you are bringing the impurities to the surface and letting them dry there.. Any preclean solvent is a slow to evaporate solvent, wipe it on, allow some time to let it float the impurities to the surface, then wipe it off with a second cloth (before it has a chance to dry) to remove the impurities. In the case of a shop environment that has high exposure to oils, silicone sprays, etc, more than one cleaning session is highly recommended. Sorry, but this sounds more like a case of incorrect use of multiple products than a defective product. Your counter guy at OReillys was correct in denying "warranty" based on these issues...






Metal prep looks non-existent. If you aren't going to DA the panel to give your primer something to bite, you'll need an etch primer or something to promote adhesion. In any case, always check one product to the next for compatibility.. Also, a proper preclean should be used, not acetone. Thinners and the like are too fast at evaporating and in many cases don't properly remove contaminants. A preclean solvent is slower to evaporate, where it floats impurities to the surface. One cloth to apply the solvent and a second wiping cloth to wipe and thus remove the impurities once they float to the surface..

 

The first thing that caught my eye was the acetone. Never use that as it flashes off far too fast. Should use a dedicated wax and grease remover that is made for prepping a panel. Wipe on with one hand and wipe off with the other.

Second thing is 2K primer on a bare panel rather than a 2K epoxy. I you want protection then put 2 coats of epoxy primer on and then while in the recoat window put down the 2K primer which is for leveling out the surface. If happy with things then put down the color instead.

 

Interjecting another issue with alcohol, acetone etc when prepping paint surfaces........

They tend to leave behind a barely visible film that can and does act as a barrier to the best adhesion. Using a paint system recommended prep cleaner is always the best policy.