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+-- Thread: Lacquer problem / White film on finish? (/showthread.php?tid=7344779)
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Lacquer problem / White film on finish? - fall - 12-03-2018
I have a problem; I just finished a piece which has black walnut and pine in the project. It was sanded and then just sprayed with Watco Crystal Clear Lacquer (spray can) which I have done a few times now with no problems. I like using this product as it dries fast and you can put multiple coats on in no time.
Well this time it did not turn out, the project started to get a white film in the finish big time. I was spraying in my shop which was about 78 degrees (wood burner Michigan) I also put a new coat on about every 30 minutes. I did put a lot of coats on but that should not make a difference (I believe) any Ideas on what went wrong and how to correct the problem. Sanding off the old lacquer would be difficult as some of the project is 3-dementional.
Thanks Richard
RE: Lacquer problem / White film on finish? - Stwood_ - 12-03-2018
Sounds like moisture under the first coat.
RE: Lacquer problem / White film on finish? - Roly - 12-03-2018
(12-03-2018, 07:28 PM)Stwood_ Wrote: Sounds like moisture under the first coat.
Agree with moisture. In addition to temperature watch the dew point also. When spraying the air temp from the air expanding and the evaporation of the solvents can lower the temp of the new finish below the dew point.
Give the finish time and or spray a coat of just thinner on it. Roly
RE: Lacquer problem / White film on finish? - jteneyck - 12-03-2018
I've had the same thing happen with black walnut, and I was just as surprised because I know the wood was dry. I think it happened on the 2nd or 3rd coat. Anyway, it has never gone away. I've heard people say if you spray it with straight lacquer thinner you can get the moisture to come to the surface and evaporate, but that's likely not much of an option if you don't have a spray outfit. But I sort of remember that Behlens or Mohawk makes a rattle can blush remover for just this problem. Maybe that will work. If not, your only option is likely to chemically strip it and start over. If you do, make sure the wood is truly dry and at 70F or so before spraying it again.
John
RE: Lacquer problem / White film on finish? - fall - 12-03-2018
(12-03-2018, 08:05 PM)jteneyck Wrote: But I sort of remember that Behlens or Mohawk makes a rattle can blush remover for just this problem. Maybe that will work. If not, your only option is likely to chemically strip it and start over. If you do, make sure the wood is truly dry and at 70F or so before spraying it again.
John
John, I did try some Mohawk supper blush and then it turned even whiter?
RE: Lacquer problem / White film on finish? - Stwood_ - 12-03-2018
I tried that stuff once. Just once........
Reducing thinner will work, but needs to be done on the first coat.
RE: Lacquer problem / White film on finish? - jteneyck - 12-04-2018
(12-03-2018, 09:18 PM)fall Wrote: John, I did try some Mohawk supper blush and then it turned even whiter?
Hmm, no clue. Guess it's time to strip it and start over.
John
RE: Lacquer problem / White film on finish? - Cooler - 12-04-2018
I painted my old Corvair in the late 1960s with lacquer. It was a humid day and the finish ended up cloudy. I went back to the body supply shop and they told me I needed to add a "retarder" to allow the lacquer to dry slowly enough that the moisture would evaporate too.
I'm no expert, (but the Corvair buffed up like a million dollars); I'd say "retarder".
This article explains it: https://www.woodfinishsupply.com/RetarderIBIB.html
RE: Lacquer problem / White film on finish? - Stwood_ - 12-04-2018
Yes, that's an old fix that does work. I haven't bought retarder in years (Conditioned spray room).
Problem is, the OP cannot add that to his rattle can. He hasn't said whether he has a spray rig.
RE: Lacquer problem / White film on finish? - fall - 12-04-2018
(12-04-2018, 04:25 PM)Stwood_ Wrote: Yes, that's an old fix that does work. I haven't bought retarder in years (Conditioned spray room).
Problem is, the OP cannot add that to his rattle can. He hasn't said whether he has a spray rig.
Sorry no spray rig. I did take some lacquer thinner to it and it did clean up the white I am going to let it set to make sure nothing comes back and then top coat it with either more lacquer or maybe even some shellac or urethane? Not sure what would be the best top coat at this time.