Lacquer Question

[dabeeler]

I am going to be spraying some Sherwin-Williams simi-gloss (they call it "medium rubbed") lacquer with a HVLP sprayer. The directions on the can do not require thinning for spray application and state to wait at least 1 hour between coats. I was reading Russ' Corner about using lacquer and Russ recommends thinning the lacquer to not more than 30% and to spray 3 coats 3 minutes apart, wait two hours and repeat. I would prefer to use Russ' suggestions if it would not cause problems. It would give 6 coats in 4 hours instead of 6 hours. Russ is also setting his sprayer to 30 psi which is higher than my HVLP which maintains pressure between 8 and 10 psi while spraying.

Is there an advantage to thinning as Russ suggested? Are runs and sags more of a problem when spraying 3 coats so quick? Does the lower pressure thru an HVLP have any bearing on thinning?

Thanks,
David

 

[RussFairfield]

An HVLP gun moves the lacquer with more air at a lower pressure and behaves different from a pressure gun. Follow the manufacturers directions and see what happens. It the sprayer won't move the finish, you can always add thinner; but try not to use any more than 30% thinner.

Each coat of the 3 and the time between each will depend on long it takes for each coat to start forming a film; and that will depend on the thickness of each coat, and the evaporation rate of the thinner. And, atmospheric temperature and humidity will determine the evaporation rate.

 

[dabeeler]

Thanks for the clarification. Would thinning speed up the evaporation rate vs. the product straight from the can? My gun moves the product out of the can with no problem so that is not an issue.

 

[alxe24]

Originally posted by dabeeler
<br />Thanks for the clarification. Would thinning speed up the evaporation rate vs. the product straight from the can? My gun moves the product out of the can with no problem so that is not an issue.

The ansewr is yes since there are less solids and more thinner so it will eveporate faster than straight from the can.