I'm blushing!

[Martian]

Morning friends. I have a small problem, and hopefully I will receive a small cure. I am curently finishing an inst. with behlens, cut to about 80/20.I live in Mich. and I would like to know what is the cause/cure for lacqour blushing? Also, I might add that it is my 3rd spraying, my first blushing, and today is a little more humid (82%)than the first two coats. I did experience a little in coat one, but I have been hanging it inside a room that has a dehumidifier in it, and the first case disappeared. Is ther a way to avoid it altogether? thank you

[Lefty Luthier]

Some lacquers are more blush prone than others in my experience. Humidity is the likely cause though there are other possibilities. Best suggestion I have is to test your blend on a piece of scrap and adjust thinner accordingly. Here in south Texas, I nearly always use a 70/30% blend or just refrain from spraying on really humid days. Behlens is fine lacquer so don't blame it for your problem though I have found that Sherwin Williams B44 CT6 is superior in any number of ways. Nearly all of the local cabinet builders use and swear by it.

[buddyellis]

Only real way to prevent it is to spray in a location under about 60% humidity. That is the primary cause (high humidity). Generally speaking, though, it will 'go away' if you let it sit for a while in a lower humidity environment, at least in my experience. They do sell 'blush eraser' but I've never had cause to purchase it. Usually, in the worst cases, spraying a slightly higher cut (70/30 like lefty said) will get rid of it. In my understanding that's pretty much all the blush erasers do: reflow the lacquer so the moisture can escape.

[Martian]

Thanks boys Hey Lefty, good to hear from you. Actually, I tried at my local s w dealer to purchase that very product, and they told me it had been dropped. I don't know if you have had that experience or not, but tomorrow, I am going to try a different s w. Sometimes people are misinformed. As Buddy had said, it tends to go away, but like I had mentioned, after about 10-15min. I have been hanginging it in a room with de humidifier. thanks again

[craigw]

I do oil varnish but when I used to refinish furniture with lacquer we would mix in retarder in the lacquer/thinner mix to slow down the dry time or use a slow dry thinner if the humidity was up. As I understand it, the blush is caused when moisture is trapped as the finish flashes off which is only a fewe seconds with lacquer. A fix we used if blush occured was to wait til the humidy went down and shoot straight lacquer thinner (with retarder added if necessary) and the blush would usually release.

[barry k]

No worse area in the country for spraying lacquer then here in Savannah Georgia. Looking at 100% humidity 90% of the year. Air conditioning the spray booth is the ONLY anwser, and have lots and lots of disposible filters available. Heres the problem, when you spray ,you need to ventilate, when you ventilate you push all (some) of your A/C outside, so through trial and error you will find a happy medium enviorment to spray lacquer. Only thing I wont do is try to spray during or right after a rain storm. Would never control blushing then. Retarder helps some, but I try not to use any other additves other then thinner.