Mike Murray
02-21-2007, 9:32 AM
OK, I need some advice. I've had my HVLP gun for several months now. It's been a learning experience (to say the least). But with a lots of patience and experimentation, and lots of reading here and elsewhere, I've learned a ton and I've had generally good results spraying shellac, lacquer, and dye stains on several projects. I'm now spraying some WB poly (Varathane floor finish) on some stair treads and I'm having mixed results.
If I use a light, airy spray, with good atomization, it doesn't seem to go on "wet" enough and I get orange peel. I assume this is from drying too fast so the finish doesn't have time to level itself. I can make the "dimples" smaller (almost imperceptible to the eye) by adjusting the air down and/or the fluid up, but I cannot make it go away completely and get a smooth-as-glass finish like I was getting with shellac and lacquer. I've experimented with 10-30% thinning, and the results are basically the same, maybe a bit worse the more I thin.
I've also tried a heavier, wet spray with lots of air and fluid, and good atomization. Obviously, this builds a thick film quickly which takes longer to dry. But I have to put it on really thick to get a smooth, even finish that levels itself. It avoids orange peel, but it's a VERY thick film, which worries me and doesn't look very good. I was wanting to build up several thin coats.
With shellac and lacquer, I've always been able to find an air/fluid/viscosity combination that produces good results in a very short period of time. I've gone through nearly a quart of this stuff already and can't get acceptable results. Is this a typical problem with WB poly? Is there something else I'm overlooking? Should I be happy with the thick film approach? Any and all suggestions are welcome. Thanks.
Mike
If I use a light, airy spray, with good atomization, it doesn't seem to go on "wet" enough and I get orange peel. I assume this is from drying too fast so the finish doesn't have time to level itself. I can make the "dimples" smaller (almost imperceptible to the eye) by adjusting the air down and/or the fluid up, but I cannot make it go away completely and get a smooth-as-glass finish like I was getting with shellac and lacquer. I've experimented with 10-30% thinning, and the results are basically the same, maybe a bit worse the more I thin.
I've also tried a heavier, wet spray with lots of air and fluid, and good atomization. Obviously, this builds a thick film quickly which takes longer to dry. But I have to put it on really thick to get a smooth, even finish that levels itself. It avoids orange peel, but it's a VERY thick film, which worries me and doesn't look very good. I was wanting to build up several thin coats.
With shellac and lacquer, I've always been able to find an air/fluid/viscosity combination that produces good results in a very short period of time. I've gone through nearly a quart of this stuff already and can't get acceptable results. Is this a typical problem with WB poly? Is there something else I'm overlooking? Should I be happy with the thick film approach? Any and all suggestions are welcome. Thanks.
Mike