Solvent Pops In The Clear Coat

[Jace H.]

Anyone experienced what is termed "Solvent Pops" in their clear coat? My painter just finished painting my 67 and he had a few spots where there were very tiny pops in the clear coat. Really hard to see unless you are under florescent lights. He has since fixed them. What causes them and will they re appear?

Thanks,
Jace Holt

[Ed Jennings]

Re: Solvent Pops In The Clear Coat

If they are in fact solvent pops, they are caused by too much build up or insufficient flash time of one of the undercoats. Excessive sealer can also cause this. When I see it happen in my shop, it is usually the result of one of the body techs trying to use primer for body filler. ( building up too thick in an effort to fill sandscratches instead of sanding the area smooth before priming) Repeat performances usually result in the body guy seeking employment elsewhere. Insufficient flash time between color coats or heavier build up in spots with the color coat can also cause the problem. Usually these appear as soon as the paint dries, so it is not too likely that the problem will reappear, especially if it has been a few days since it was painted.

[Shannon Burgess]

Re: Solvent Pops In The Clear Coat

Here is a very good description of solvent pop.

http://www.sherwin-automotive.com/reference/troubleshooting_guide/solvent_popping/index.cfm

This entire troubleshooting guide has a bunch of good info:

http://www.sherwin-automotive.com/reference/troubleshooting_guide

Shannon

[Jim T.]

Re: Solvent Pops In The Clear Coat

Ed I painted my 70 in March 92 with Dupont lacquer. It turned out really great for my first. About three years ago near the middle of the hood these little bumps appeared. These appearing years after painting what do you think it could be from without seeing the damage? The car is in my garage most of the time and usually covered when parked.

[Patrick H.]

Re: Solvent Pops In The Clear Coat

Jim,

FWIW, the previous owner painted my Dad's 72 convertible just before we purchased the car. It sat in a garage full time after we bought it, and it took about 3-4 years for the solvent pop bubbles to show.

Patrick

[Ed Jennings]

Re: Solvent Pops In The Clear Coat

Jim, fiberglass is sort of a different animal. I don't think you would ever see this happen on a metal car. I have seen just what you are talking about happen, and apparently contaminates or solvents can be trapped in the glass itself and find its way to the surface months or years later. That's one reason I don't like to use striper of any sort on fiberglass. That's my read on the subject, others may have a different view.

[Bill Stephenson]

Re: Solvent Pops In The Clear Coat

Jim,

------Is your 70 air conditioned?I have seen oil intrusion thru the hood from the bottom up many times.Hard to fix.A friend of mine with a 67 got so tired of redoing this that he cut the section out of the hood and grafted in a piece out of another hood.As well,he fixed the source of the problem,and put a home-made shield on top of the pulley to prevent a re-occurence.I am in no way advocating you cut a hole in your hood!.......So,can any of the good fiberglass guys on the board give us a method to fix this problem without going this far?..............Bill S

[Jim T.]

Re: Solvent Pops In The Clear Coat

Thanks for the replys Pat,Ed, and Bill.
Yes my 70 is air conditioned. I stripped the paint with a chemical stripper off the hood for the reason you mentioned, air conditioner oil contaminated hood. For about 3-4 years or more with only the factory primer the hood I would wash the hood area where I could see the contamination that surfaced through the hood I would wash the area often with Dawn knowing this would be a problem. I was not in a hurry to repaint the complete car.
The area today that has the problem is more over the air cleaner area on the passenger side.
I have a pretty home made shield over the compressor that captures all the oil, but did not in the earlier years.
When I painted the whole car I sprayed two color coats in November and left it sitting until March of the following year and sprayed the final two coats.
I have wondered if I could improve the appearance of this area if I color sanded it to smooth the area?

[Dennis C.]

Re: Solvent Pops In The Clear Coat

Ed - Would agree with your post on this subject. Dennis