Primer Lifting

[Mike Dursky]

Put some primer on some plastic motorcycle panels that I had repaired and the primer wrinkled and lifted around the perimiter of the repair. I resanded and wiped it down good with grease and wax remover and primed again and got the same thing. Seems like the primer is reacting to whatever is between the paint and plastic. Any ideas as to why this happened. Do I need to resand and apply a sealer ? It only did it on one part .
Thanks
Mike

 

[ezrider]

MIke, plastics are difficult to understand.sometimes they react in the strangest of ways. i think you would have the same problem with a sealer and probibly even epoxy primers. your best bet in my oppinion would be to use a water born primer surfacer just to make sure it dosent happen again. water born primers do take a lot longer to dry but they hold just about anything down.

 

[Mike Dursky]

ezyrider,
Would I be limited on what paints I could use with a water base primer.Mostly looking at using PPG and candy colors. And, could you give me some specifics on this primer. (what to look for)
Thanks
Mike

 

[Mike Dursky]

I noticed some "Plastic primer" on the autobodysupply web sight. Would this be worth a try ? Did not see any water based primer.

 

[ezrider]

Mike, sorry i took so long to get back to you. Plastic primers are usally just adhesion promoters that you apply before either epoxy primers or primer surfacers. plastic primers are usally as thin as water, maybe even thinner. and as far as being limited to what you can put over WB primer, no , once cured you can top coat just like any other primer.

 

[blaino]

Hey Mike,

If your going to use PPG they try MP 178 Plastic Primer. It seems to work good for me. Spay a thin coat then prime and seal.

Check it out

http://www.ppg.com/refinishftpsite/docs/ob004.pdf

 

[ezrider]

But it dosent solve lifting problems, like i said its an adhesion promoter not an epoxy or surfacer.

 

[rex]

You need the waterbourne stuff Joe said and PPG makes at least one although I can't tell you the product #.What's happening is the solvents are getting under the primer and plastic base where you sanded through on the edges.Urethane based products have some pretty hot solvents and they're designed to eat in to undercoats.I can tell you how to paint something without sanding it or using adhesion promoter and it won't come off and featheredge beautiful when sanded,that's an example of how hot it gets.Get those edges covered with waterbourne primer and it'll stop,the only other options are strip them to bare plastic or buy new ones to start with and don't break through the primer sanding it.

 

[Mike Dursky]

Got ya ! Thanks.