I don't know where to start. I've been on this problem for the better part of 3 months.
I am building a series of bed sets for my kids. For the first one, I used water based stain and sprayed some satin saman ( www.saman.ca ) varnish and it went on smooth and even, not perfect but good enough.
For the second kid, the color needed to be more vibrant so I switched to Behlen Solar-Lux for the stain and was recommended EM1000 for sealer and EM9000 for finish, satin again.
Being that I'm not the quickest, there was almost a year between purchasing the product and using it. The stain went on nice albeit being faded without finish. Then the sealer unevened the stain and the varnish cratered on me.... I found a couple of references online stating that EM9000 will actually crater after sitting on shelf for a few months...
I gave up and sanded back to wood, restained with the Solar-Lux and tried to varnish with Saman. This time the color is fantastic. I sprayed 3 coats of gloss varnish and then added a coat of satin. The 3 coats of gloss went on really nice and even. The coat of satin was a disaster. It feels like sand was spread in the finish.
For the last two weeks I've been trying to tweek the way I lay it down and no luck!
I built a spray booth (with a fan and filters), cleaned all of my compressor lines, added a filter right before the gun. I tried to spray with 25psi, 20psi, 15psi, 1.5mm, 1.7mm, 1.9mm, switched gun, hose. I changed for a new can of varnish. Today I even went and bought Varathane Diamond Clear and got a similar result.
Here's the process, I hope someone can help me pin point where I go wrong!
-Sand the birch up to 150
-Spray Solar-Lux
-Let dry for 1hr
-Spray gloss Saman wet coat (pretty much all absorbed instantly)
-Wait 1hr
-Spray gloss Saman wet coat
-Wait 1hr
-Sand with 220 or 320 until flat and even
-Spray air then wipe with dry rag
-Spray gloss Saman wet coat
At this point it looks great and not too rough
Wait an 1hr or overnight
-Sand with 320 until flat and even
-Spray air then wipe with dry rag also tried wet rag
-Spray with Saman or Varathane satin
-Open hells gate and throw the whole thing in the fire
At that point it feels like sand in the finish no matter what I tried.
I also tried on different test pieces and I can reproduce the problem... I can't seem to get it right anymore...
Gloss
gloss.jpg
Satin
satin.jpg
In the pictures you can see the gloss coming out nice. In the satin, you can see the bumps in the light reflection...
Any idea welcome!
Thanks,
Sébastien