PPG Duracryl Acrylic laquer cracking during application?

B

Brad J.

Oldtimer
Any old laquer guys around anymore? I learned on laquer but shortly there after we switched to base/clear.

2 fenders sealed with epoxy last night

This morning I sprayed the first coat no problem. The second coat on only 1 fender decided to craze. I set it aside and will have to resand.
It's 70 degress out with 60% humidity using 65-80 degree thinner.

I sprayed the first two coats pretty wet with 15 minutes flash. 5-10 per tech sheet.

I can't remember the ins and out of spraying this stuff. This fender was the last part on a front clip that was damaged and PPG black laquer was used.

The hood did had a couple spots do this during application and I sprayed 5 wet coats with 15min between and it was pushing 80 degrees that day.

I'm going to thin my coats back but want to keep 1:1.5 mix ratio that is recommended.

Any thoughts?
 
if lacquer flashes too much it will shatter. 5-10 is pushing it. i let it flash just long enough to hold . also you cant grease lacquer. you have to build the coat.
 
I was able to finish my 6 coats on the one fender. I kept the 15 minute flash but sprayed finer coats. I'm a little nervous as I did 5 nice wet coats on the rest of everything and nothing rubbed through. These are much thinner coats so I will be extra carefull. Just trying to tiptoe through the rest of the job to make sure I make enough. This was an insurance deal that I normally stay away from.

Thanks Shine, I will shorten up my flash times. I was really dumping it wet. I started spraying this stuff and wasn't taught properly so I never really knew the what and why of this stuff.

I have one fender left and borderline enough paint. I had enough til this happened. Stinks because it's an hour and half each way to the PPG dealer that sells laquer and it comes right out of the profit it I need more.
 
Shine,

Since I have two coats on this do I have to sand it back off to my epoxy or can I just 400 block it smooth and start over?
 
Block it smooth and start over, what is under the lacquer besides epoxy? What reducer/thinner are you using? I've done some lacquer repairs with SPI reducer per Barry's recommendation and found it better than any lacquer thinner I've ever used.
 
when lacquer has flashed good the next coat can craze it. instead of a wet coat all at once do a med coat followed by another one. the first will open the surface then you can build a wet coat. years ago i did a mustang , left it overnight then finished it off the next morning.
hit the first coat wet and checked the whole front end. lacquer is not as easy as it seems.
 
I 400 blocked it smooth last night. With two coats I only went through in a couple spots. Not as worried about break through after seeing that.

This fender appears to be DP40 epoxy with k200 build primer. I spoke with the guy that painted it 25 years ago and he used ppg on the car. The fender that painted out good was stripped to bare and brought up with SPI epoxy and turbo 2k and then sealed again with epoxy.

Interesting thought. I painted a fender skirt, 3 front body aprons, 1 fender without any issues dumping 5 coats on all of it. The hood and this one fender was sanded laquer with a few repair areas. Hood and fender were sealed with epoxy and sat overnight though. Probably coincidence but the parts with the laquer under were problematic.

I used ppg duracryl acrylic laquer thinner. I was thinking the opposite with all that laquer filled paint being sprayed onto the next coat that I would want it flashed extra good but the case is opposite. I'm remembering bits and pieces of this happening occassionally but memory doesn't retain the old tid bits.

Anyway, thanks for the tips as I always like to know why.
 
Which Duracryl thinner? Ditch the lacquer thinner and switch over to SPI reducer. The epoxy sandwich can be a problem if your solvent is harsh.
 
Bob Hollinshead;40170 said:
Ditch the lacquer thinner and switch over to SPI reducer. T.
Click to expand...

X2 on that! Reducer works way better for lacquer than the lacquer thinners made today.
Most are junk.
 
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