Help!

[Kent Barnes]

HELP! #I started spraying lacquer on Harlan #2 this morning, and got a couple of patches of blushing. #This is the first coat of lacquer. #I think it was too humid outside. #Suggestions?http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

[Darryl Wolfe]

Tomorrow will tell..sometimes you can force it out with light coats of thinner.

Don't assume its not coming from your compressor

[Kent Barnes]

I did bring it in the air-conditioned house where the humidity is lower. It's hanging from my dining room light fixture (my wife loves it when I do that).
Light coats of lacquer? Maybe a misting of straight lacquer thinner from an airbrush. I'm using a dryer on the air compresser, but it is pretty humid outside. I sprayed Harlan #1 in August of last year, and I saw some slight blushing, but it did go away as it dried.

[Kent Barnes]

Well Darryl.....
I just went out and drained 1/2 - 3/4 gallon of water from the tank of my air compressor. I know better than to start a sprayiing project without doing that! We'll have to wait and see what it looks like tomorrow.

[Darryl Wolfe]

Bingo...most of the time it's your compressor

[Mteresko]

You should always filter the air from your compressor for spraywork. When I did alot of spraying, I would use a disposable plastic filter right at the gun. Also, if you thin your lacquer with a little retarder thinner, it will help solve the problem. You can often get rid of the blush by lightly spraying the piece with a mixture of regular lacquer thinner and retarder.

[Dale Ludewig]

In humid weather, you really should use retarder.
As for your current problem, you might try LIGHT buffing with #0000 steel wool. Sometimes I've found the blushing is sitting right on the top and can be removed that way. I also have had luck using a heat gun, although this must be done very carefully or you'll bubble the lacquer. However, you don't have much buildup up, so that shouldn't be much of an issue. The idea is to get the moisture that's trapped hot enough to kind of works its way out.
And as others have said, sometimes a light coat of thin lacquer with some retarder will do the job. Good luck!
Dale

[sunburst]

That blush probably wont be a problem as you continue to do your finish work and follow the advice you've gotten, but if it doesn't go away, get some butyl cellosolve (from stewmac or wherever) and spray on mist coats 'til the blush is gone.
That will work at any time, even if you've sprayed lacquer over the blush without it going away.

BTW, I've been taught not to use steel wool on lacquer between coats because of the chance of leaving microscopic bits of steel in the lacquer, but I must admit I've done it with no apparent problems.

Nice lookin' burst, by the way!

[Kent Barnes]

The knowledge and willingness to help on the board never ceases to amaze me. #I just went out and "misted" some straight lacquer thinner of the blushing with my airbrush, and it's gone!!
Thanks guys!!!!!
http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Luthier Vandross]

Blushing goes away when you shoot the next coat (it blushes too) or start leveling.

Heat lamp takes it out in seconds.

Nice shading work! Pretty!


M

[Kent Barnes]

Thanks for all the advice. #After I drained the tank on my compressor, I just shot 4 more coats of lacquer on the mando without any blushing!

Thanks again! #I'll post more pictures soon.

[Luthier]

Great advice from all!! You should get a water filter and hook it up to the hose as it comes from the compressor. It should be emptied from time to time. I am also in agreement with the retarder use in humid weather but be sure to allow more time between coats. DO NOT use steel wool between coats. The fact is, you just need to scuff up the finish the next day to help the new layers adhere better. I use 220 opencoat silican carbide paper. I spray 4 light coats / day. The following day I scuff it up and do 4 more light coats. I do a total of 12 coats, let is sit for at least a week and then begin the final sanding, rubbing, and buffing.

Don

[Luthier Vandross]

I think you guys put on more than you need.

Lacquer doesn't need a scuff before the next coat, it burns together, especially with retarder. I shoot all my coats in 2 hours, 4 coats, 20-25 minutes between, wait a day, then level, 5-7 days, and buff.


M