[Damien89]

Hi I am damien89. I am new here. My friend has a small bodyshop. The problem is having is that the clearcoat when sanded and buffed it is coming out very shiny but after a couple of weeks the clearcoat starts to appear like there are small holes (microscopic size) all over the paint. Could this be because he still dont have a paint oven and the clear coat isnt drying out as its suppose to be? When you touch the paint it feels like its dryed but again could it still be not dryed out?

Thanks

 

[kenseth17]

Sounds like solvent pop to me. Are you allowing enough time between coats of basecoat, enough time for the base to sit before clearing and enough time between coats of clear, painting in a warm enough temperature. It sounds like you have solvent trapped deep and a few weeks later they come out leaving the holes in the process, rather then too fast reducer or activator causing the problem. Dark colors such as black are slower and should allow more time to clear over. Also cheaper lines of base may require more time, as many are slower drying systems. I know I had a real problem with pop when painting dark colors with the limco the shop was using years ago. Shopped switched to a different line of cheap base and clear, and with the same time between coats, didn't have the problem again. Another problem could be a cheap gun or one that doesn't work well with todays higher solid materials, requiring you to really hammer on the clear to get a nice glossy look without dry spots. Try avoiding using a slower activator or reducer to allow more time for solvent to escape allong with allowing more time between coats. But from your description of the time when its occuring, I think the solvents are getting trapped earlier in the process, being primer, sealer or base. Hopefully Barry and others will respond to this question to confirm what your problem likely is. Or try a search of old threads about solvent pop, as its been covered before. If you have the time, allow extended times between coats, even letting the base sit overnight before clear. If you are only doing small parts, maybe setting an infared heat lamp on sealer or primer, on base before clearing can speed things up for you, but I think your best bet would be to extend times between coats, exspecially between base and clear if you have the luxury of time.

 

[MARTINSR]

Yep, that is likely what it is. The first thing you have to think about is, does the solvent "temp" choice match the metal/shop temp?

Second thing, are you allowing proper flash in between coats and products?

Third, are you applying it with too low of pressure or some other reason that the gun is not atomizing the paint/sealer/clear?

Forth, are you applying it with too slow a gun travel that would build up too much film that is of course full of solvent?

These are things to think about, any of them done a lot or a number of them overdone just a little are going to give you the same results.

These air pockets could also be if the metal temp is TOO high, "cooking" the film as it drys making air pockets.

Brian

 

[Damien89]

But i thought that if you let a long time after you put the basecoat then the clear wouldn't stick to the base properly.
Could it also be that sometimes the garage is a bit cold?
Once my friend was painting his car with an orange mica pearl base the temp was 22-23c he used fast activator and the base had to be done in 5 stages, in the 4th stage we were seeing the paint when it was being sprayed on the car it was coming out with loads of cloudness. We think it was the activator being too fast for the temp.

 

[Bee4Me]

It's solvent pop delayed IMO.
You trapped the solvent as the clear skinned over and buffed out fine but after some time,the solvent eventually made it's way out.
You used a slow catylist or reducer and did not allow enough flash time between coats or between base and clear application. I believe it was with the clear coats and after some cure time or a bake cycle,sand and reclear with the proper temp products with proper metal temp.

 

[xntrik]

I have a similar problem with PPG paint.
My buddy a body shop owner/paint man and I stripped to bare metal, etched and sealed, colored, and cleared with all the correct PPG products. Sanded with 2000 and buffed. Looked like a Boyd job and lasted 6 yrs. Then in less than a month (yes) developed little tiny micro pits everywhere and won't polish to a shine.

PPG nor anybody else can tell me why.

So do I want to spend $2000 on paint and materials again???????

Sad, since the original acrylic enamel lasted 43 years and looked decent.

 

[Damien89]

I have a similar problem with PPG paint.
My buddy a body shop owner/paint man and I stripped to bare metal, etched and sealed, colored, and cleared with all the correct PPG products. Sanded with 2000 and buffed. Looked like a Boyd job and lasted 6 yrs. Then in less than a month (yes) developed little tiny micro pits everywhere and won't polish to a shine.

PPG nor anybody else can tell me why.

So do I want to spend $2000 on paint and materials again???????

Sad, since the original acrylic enamel lasted 43 years and looked decent.

That is what is happening to us but not after 6 years but after a couple of months. At first the paintjob looks like a pro painter has painted it but after a couple of months it looks like cr*p and the only easy way out is to sand again and buff but with that process your making the clear more thin and risk sanding the base. How much time should you let the base settle before you give it the clear? And how much time should you wait between one layer of clear and another. Please do remember that we do not have an oven.

thanks for the great info and happy new year to everybody

 

[baddbob]

I have a similar problem with PPG paint.
My buddy a body shop owner/paint man and I stripped to bare metal, etched and sealed, colored, and cleared with all the correct PPG products. Sanded with 2000 and buffed. Looked like a Boyd job and lasted 6 yrs. Then in less than a month (yes) developed little tiny micro pits everywhere and won't polish to a shine.

PPG nor anybody else can tell me why.

So do I want to spend $2000 on paint and materials again???????

Sad, since the original acrylic enamel lasted 43 years and looked decent.

Etched, sealed, colored and cleared. What exact products were used? Bob

 

[adtkart]

Good question Bob. Quite often someone will post a problem or question like that. They only provide part of the information, and cannot get good answers that way. It's like saying my car won't start, what's wrong with it?

If you post the products used, the proceedure followed as far as steps and times, and the conditions, such as temp and humidity, you can get better answers. It is hard enough to "Guess" what happened over the internet. If all the information is available, you can get better educated answers.

Aaron

 

[STATUTORY GRAPE]

Don't trick yourself into thinking you "NEED" an oven for a good paint job,,a heated shop (70 degrees) works just fine. imp: Also, when you buy paint jusk ask for a tech sheet, all the flash times, mixing ratios, etc...will be on there

 

[xntrik]

Etched, sealed, colored and cleared. What exact products were used? Bob

Got with him last night and looked at the paint. We're thinking back 5-6 years here, ok.

All materials were 3M and PPG.
This was a roof repaint job. Just the roof.

Sanded to bare metal.
Primed with he thought "250" for bare metal, I think we used DP 90... tinted lavender color.
Color was PPG's best base coat, 90 Lincoln Navy Blue. 3 wet coats.
Clear was PPG's 2000 series. We could not agree which number. 2001 or 2010. Whichever was the high UV resistant. 4 wet coats. Sanded with 1500, buffed with Meguiars, foam pad.

The aluminum strips that join the C pillar to the roof/back glass look perfect. They were never sanded.

The roof looked good for 5 years then went bad in a short time span of maybe 2 months. It is equally dull all over and resists any polishing. But does not show any clear peeling, etc. just equally dull. We are pretty sure that the clear has not been sanded through nor buffed off since it is so equally dull all over.

Neither the local PPG store nor the PPG state rep has "flow charts" nor flash time charts available. No kidding. They kept telling me it is up to the paint man and his experience. I've always preferred PPG but their customer service sux.
Thanks, x.

 

[xntrik]

I am facing spending $ 2000 for paint and materials for my 63 project, so I am reluctant to do so until I get some answers.

Most of the base/clear jobs on rods are always covered and garaged.
I have seen lots of jobs that sit out go bad in 2-6 years, regardless of paint brand.

I realize that time is the only true test of a finish, so what have the paint companies learned in the last 6 years that might be of value to us now?

 

[barthmonster]

Seems that with EXACTLY the right shop temperatures, following the manufacturers flash times is a thing best done only with the top (expensive) brands & lines of paint, i. e. PPG, Du-Pont, and other top names.
Longer flash times are better for show-paint or to reduce solvent pop: read what Barry's site says on flashtimes, 45 minutes!! :

http://www.southernpolyurethanes.com/perfect paint.htm

I'm a newbie here, but hey, maybe Barry is busy!!

 

[xntrik]

So there is no real answer??????

PPG doesn't know, can't recommend specific paint products?

Anybody else?