Solvent Pop?

I've never sprayed basecoat clearcoat before. I've sprayed some of the smaller parts, and the inside of the trunk lid of my current project, and I seem to be getting solvent pop in some areas. I'm using Dupont 72500S Chroma Premier over Hot hues base. Would it help to let the clear sit a couple of hours between coats? Or is it best to do coats 15 or 20 min. apart? Or am I just putting it on to thick? I'm using a 1.8 tip on my gun. Thanks for any ideas that anyone might have.

 

Solvent pop/ fish eyes generally occurs due to contaminates in the air or on the panel, or laying the paint on too thick. The first thing I would ask is how do you clean your gun ?? With reducer or laquer thinner? Cleaning with laquer thinner could cause this as well
As far as time, Lay down your coats according to the tech sheet.
It could be that you are just putting them on too thick. but make sure that the panel is clean and you dont have any chemicals or oils in the air or on or around whats being painted. things like wd40 sprayed in the area can wreak havok on paint..

 

How warm is the room and what temp range reducer are you useing?

 

Hey,

Are you sure that what you have is a " solvent pop '' problem, and not a moisture problem? Contaminated surface prior to refinishing?

Swanky Devils C.C.

 

Vinnie of destruction: I did use laquer thinner to clean the gun, but I would have thought it had plenty of time to dry. Would it still be an issue?

PRL98: The reducer I had was for 70-80 temp, and the room was around 70. I hope to be painting the body tomorrow, and it will be in the 60's so I got the reducer that is for 60-70.

Thanks for the ideas guys.

 

Thats common here right now due to moisture. My friend uses a heat gun to get the base coat a little drier so the clear can go on without clouding or popping.

 

what temperature are you spraying at?

Is the reducer your using in that temperature range?

Is this a very humid environment?

 

I would rinse with reducer, spray some through, then let it dry before paint goes in the gun.
You said you think you may be spraying to heavy as well try coating a little thinner .
Are you using hvlp gun?

 

Not a real humid room. I've drained the tank, lines, and have an inline water seperator, and filter, and I'm using an HVLP gun.

 

Try adding some "Smoothie", it works great with fish eyes.

 

Also use a small filter that goes right on the end of the gun (about $6). My guess in your case would be the solvent popping is from the basecoat, not the clear. Try lighter coats with more time between coats. Too fast of a reducer will cause this as well.

HVLP guns are tricky when you're first starting out. You really need the high volume (not pressure) of air. Are you setting the air pressure at the gun or at the regulator by the compressor?

Might want to consider borrowing a conventional gun and doing a test panel before you shoot the whole car. Just my .02, good luck hope it turns out well.

 

Solvent popping is not to be confused with fisheyes. They are two very distinct problems and each has their own fix.

Solvent popping is caused by solvents being trapped under a skinned surface. That solvent has to go somewhere, so when it forces it's way up through the skinned over surface, it leaves a tiny hole(s).

Causes are: too fast of a solvent for the conditions, not enough flash time between coats (including primers, sealers and base coats) and coats applied too heavily.

Fixes are: slower reducers, more time between coats including making sure that the primers, sealers and/or basecoats are fully dry before topcoating, spraying lighter coats.

 

Fish eyes and solvent pop are to different problems. I used to get solvent pop because I was holding the gun to close to the panel. You want a good 6 to 8 inchs. More solvents will leave in the air at that range. To close and you trap solvents in the clear. Never had a problem cleaning my guns with lacquer thinner.

 

Good point PeeVee. Reducers are made up of a variety of solvents, some of which are designed to evaporate immediately as the liquid exits the gun and some of which is designed to stay suspended in the liquid to aid in flow-out among other things.

With the gun too close, the solvents that are designed to evaporate quickly do not have the time to do so and are forced into the layer of paint being put down on the car which can definitely result in solvent popping.

 

The above post is right on the money.
Solvent pops appear as small pin like holes and fish eyes are kind of spread out and look like oil spots.

 

The 1.8 tip is WAY too big for most basecoats.I'd guess your putting too much material on and not allowing enough flash time between coats.

 

Thanks for all the info guys. I'll take all the advice and try it in the morning. If it comes out good, I'll post some pictures, if not, I'll just crawl into a hole.

 

My next question would be what pressure are you spraying at?

 

Solvent pop is from laying the clear too thick, also too soon in between coats.

Fisheyes are from contaminates, before clear and sometimes after.

 

What gun are you using? I'm with customcarpainter a 1.8 is way to big for bc/cc. That has got to be like spraying with a garden hose. 72500 is designed to be baked in a booth, you may be better off with 72200. They are both great clears, and to expensive to waste. I think you should look into another gun or smaller tip (1.3 or 1.4) before you waste your time and clear. Proper gun setup is a big part of the battle in a quality paint job.