[Derkyb]

Fairly new to painting but feel I can hold my own. I just rented a new shop to paint in and looking for a booth. In the meantime Ive been doing small jobs like hoods fenders and bike parts. This weekend I tried a new clear ppg2021 it sprays beautifully and a bike fairing turned out nice. A few days later I painted a hood with the same stuff except for the base color [same brand though shopline] and it solvent popped liked crazy. There must have been 1000 or more little craters that at first looked like dirt as i watched them form but closer look revealed no dirt just tiny holes.

Heres the situation:
I used jp 202 primer
shopline paint w jr 505 medium reducer
ppg 2021 dcx61 hardener jr505 reducer
shop was steady 65 degress
hood was in the sun prior to painting metal wasnt cold
waited 15 min between two coats of base and 30 min between three coats of clear and it didnt show up til third coat was being sprayed
drained/changed tank filters
It was so bad i waited a few days resanded and sealed then sprayed again with same results I waited a few hours and sprayed shopline 6061 on top of it didnt pop and had a good shine but you can still see the small craters if you look closely. WHAT A MESS free job! any ideas on what could have caused this?

[Runnin'OnEmpty]

The problem was probably a combination of using the medium reducer
and the relatively cold temperatures; and 30 minutes just wasn't enough
time for all the solvent to outgas in the lower (1st) coat of clear.

Using a fast reducer, or if it was warmer, or waiting longer between
the clear coats would have prevented the soda pop effect....

[milo]

Curious why you wouldn't use the reomended "DT" reducer in that clear?..

http://www.google.com/search?sourcei...ner+dt+reducer

[Hotbo]

you needed longer than 30 minutes especially after the 2nd going to the third

[302 Z28]

TWO mistakes in my opinion. One not using the recommended DT thinner. Two not waiting long enough between coats is more than likely the real culprit. FWIW, IMO the PPG DCU2002 clear is a much better product.

Vince

[Derkyb]

asked the ppg platinum paint seller today and they said jr is used instead of dt all the time with no probems, guess its cheaper and suffices. I think i discovered my probem tonight though. i had just purchased a devilbiss dryer system a few days prior didnt think to check the dessicants since i hadnt really used the compressor that much but when i pulled the container apart water just flowed out and the dessicants were white and the indicator was pink. That would explain why i didnt have any problems a few days prior using the same stuff, temp, and recoat time. changed the dessicants and trying to spray it again tomorrow, will update. Thanks for the advice

[Hotbo]

never use a cheaper reducer.

need to wait longer going into the 2nd the 3rd coat.


PPG paint seller,LOL!!!!!!!!!!!


maybe it was the Dessicant maybe not?

[Underground]

Originally Posted by Derkyb

[U]it didnt show up til third coat was being sprayed[/U]

I've never seen solvent pop happen WHILE the clear is being sprayed.

[302 Z28]

Third mistake: Hardly ever take as gospel any information from a paint seller

Vince

[Derkyb]

Problem solved!!! but at the expense of my friends paint job. So a week later my friend is getting ready to paint his car in my garage. He was using a totally different paint system and gun. As he began spraying the clear just as i had done we noticed the one million fisheyes begining to appear after the second coat. So then I narrowed it down to what was common the compressor/dryer. I checked the dessicants we had just replaced and they were pink already and the filter had a hand full of water even after it was drained before he started shooting. I opened the purge valve and had him pull the trigger and water formed in my hand as he sprayed. We junked the dessicants and put two rolls of toilet tissue in the canister and the air was dry as a bone and he finished the job with not too much damage. So the problem is that my air line is level all the way to the filter and letting the moisture form the compressor come right to the gun. Not sure why there is so much moisture on a cool dry day any ideas?

[302 Z28]

Sounds like a redesign of your air delivery system is in order.

Vince