Lacquer problem / White film on finish?

[richard poitras]

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

[Jim Becker]

May have been a moisture issue...but I'm not an experienced solvent-based lacquer person. (Please be careful with that wood-burner in your shop and solvent based lacquer. The fumes are explosive)

[richard poitras]

Jim I don’t think it is moisture? as like I stated it was 78 inside the shop and 35 outside and the shops wood burner was on for two days. It seemed to start to bleeding white the more I put on?

Note:
As far as the fumes being explosive you are right but the project is only 4’’ by 7’’ a set of 3-D book ends and when I spray in the 1100 sq ft shop I turn on the overhead vent system and crack a window so there’s not that much as far as fumes with something this small in a shop this large anything larger I wouldn’t even think about it. Let alone all the over spray.

[Wayne Lomman]

It is moisture entrapment. Absolute temperature is no guarantee. You need to monitor dew point and make sure your substrate temperature is at least 3C above the dew point. You are also pushing it putting on so many coats on the trot. You really need to wash it off and start again. Limit yourself to 2 or 3 coats in a day, leave it overnight and final coat the next day. You will save lacquer and get a better job. Cheers

[Jim Becker]

My thoughts were very much along the same lies as Wayne...and I know he has a lot of experience with lacquer.

[Lee Schierer]

I had the white blush problem on a couple of small areas on a project. I heated them up with a hair dryer and the blush vanished and did not come back.

[richard poitras]

Thanks guys, I did not know that putting on to many coats to fast could cause moisture to get tramped in the mix. I figured with the higher temp that it would dry faster and being it’s a wood burner it is a very dry heat. Not thinking of the flash over and entrapping moisture. That’s what I get for pushing it and thinking I am smarter than the rules of application. I guess you are never too old to learn, but that’s why I ask the forum you guys are the best.
I did wash it with lacquer thinner and let it dry and and it seemed to clear it up as I don’t see any white.
What are your thoughts to finish it off now as it has high and lows of lacquer and I need to equal it out? Try more lacquer or maybe spray some shellac on it or a urethane?

[Lee Schierer]

Since each new coat of lacquer softens and bonds to the previous cat(s) I would level out the existing coats with 220 or finer sand paper and apply one or two more even coats.

[Wayne Lomman]

Lee has the right advice. Don't mix your coatings randomly. The lacquer is fine. Cheers