I was spraying unthinned Sherwin-Williams CAB Acrylic last night on a mahogany bed I’m working on. This is my first time using CAB Acrylic. I’ve had good success spraying conversion varnish, deft, shellac, etc. I’m using the infamous HF purple gravity HVLP gun with 1.4 mm nozzle. The ambient conditions were about 80 degrees, low humidity and a slight breeze outside where I was spraying. The test piece came out great so I proceeded to spray my first workpiece. Much to my dismay, I found out what I think is called flashing where the finish dries before it hits the surface. I was able to put down an acceptable wet spray, but the overspray turned to a fine whitish residue almost instantly. I tried increasing the volume flow but that didn’t help.
Any suggestions / experience with flashing or working with CAB Acrylic in particular?
Replies
Combine high ambient air temp (generally anything over 75 degrees) and low humidity with a heat-generating turbine and you get accelerated flash-off. Even on mild days the turbine canbuild up heat over extended use and you will have to adjsut your thinning rate and gun settings. A lot also depends on the quality of turbine you are using: 3 and 4 stage turbines produce less heat than more inexpensive 1 and 2-stage turbines. If adjusting the pressure to reduce the atomization while maintain a material flow doesn't't produce the results you want, add lacquer retarder to slow the flash-off. Retarder is available from any professional paint store or automotive paint supple house.
Doug
I've no specific advice regarding that brand of lacquer as it's one I'm not familiar with, except that you might consider using a little retarder as others have suggested. I'm also not familiar with turbine guns as I use conversion type HVLP guns, but I did notice a muckle great timber weakening thunder shake in your image, flashing-4.jpeg.
You might consider remaking that bed rail, especially if the occupants intend to do some serious horizontal jogging, ha, ha-- ha, ha, ha. Slainte.
RJFurniture
As others said, add some retarder. Lacquer looks like its applied a bit on the heavy side also. Sgians right about that crack...wouldn't last a night in my house! I wish...
"muckle great timber weakening thunder shake"
LOL WHAT!? Get the idea but sounds like jibberish... Should add that to the discussion on shop slang for those of us looking for translation.
AE
LOL,
Ya I noticed that crack too, a climax could end up in an anti-climax.
With nitrocellulose lac I would just thin it out some more and add retarder. I don't know about the CAB stuff, but the S-W people will tell you what to use (for a retarder).
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"I tend to live in the past because most of my life is there."
-- Herb Caen (1916-1997)
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