HVLP: What Tips to Use for Shellac? Karl, Leon?

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Very true. Temperature, humidity, and thickness of application may have as much to do with your finish as anything, but fine tuning your tip for actual use is just as important. You can spray with the wrong tip (say the 2mm for lacquer) and get away with it. Likewise, you can shoot a low color saturated latex with a 1.2 tip and get away with it if you thin enough.

If it were me, and sometimes it is, I would hit that 2# shellac one more time and cut it about 20 - 25% depending on the weather. The hotter, the less I would thin. I prefer a smaller tip and use a 1.2 mm on my gun, but doubtful you would find any difference. I like to shoot it thin, just thick enough to hang onto a vertical surface. The finer tip will put out a finer finish.
As for BIN, I shoot that unthinned out of my gun with a 1.5 tip, and have shot it with my 1.2 tip as well. A call to Zinsser revealed that they put in some kind of agents that make it more viscous in the application than homemade shellac, and they told me that it was formulated with the knowledge and intent that it would be gun applied. It is one of the few materials I just pour in the gun and shoot.

It's easy. The preferred application thickness for almost all top coat clear (including shellac) materials sprayed is 3 mil. Odd, but it holds true for just about anything I have ever seen. You can apply more if you want, but 3 mil is the standard. So what does 3 mil look like? Pull out a dollar bill and check out its thickness.... right at three mil.
So spray some finish on a test board, take a razor blade and cleanly scrape away a side so you can see a profile and compare it to your dollar. Personally, I have never even used a gauge.
You can shoot most latex finishes thicker, and certainly 5 mil is within that range. For that, I use my 2 mil tip, and during our hot summers I shoot that unthinned. For more moderate weather, say the 70s, I thin latex about 20%, then shoot it with my 1.8 mil tip. Even though you don't have to thin latex with a 4 stage turbine or a CAS gun, it works better for getting a finer finish.
Robert
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On 12/24/12 12:10 PM, snipped-for-privacy@aol.com wrote:

Tanks a rot.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
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