problems spraying Kem Aqua lacquer

[l-lopez]

I am using Kem Aqua for the second time. The first time did not produce results comparable to my experience with Sherwin Williams Nitro lacquer - so I guess I need help.

I am using a Sharp Cobalt HVLP conversion gun. The results look a bit rough - sometimes it even looks like a dry application.

Today I did a couple of new samples:

I sanded the piece to 220, raised the grain and let it dry, and then sanded lightly again.

The test piece and the Kem Aqua sealer were stored in my shop at about 65-70 degrees.

I have the gun and compressor set as per Sherwin Williams instructions. air at 45 psi fluid tip pressure measured between 5 and 10 psi fluid flow control wide open fan set about 12 inches high gun about 8 inches abouve the work piece (piece is lying flat and the gun is pointed down)

I put two coats of sealer down about 30 minutes apart.

I tried varying the tip pressure and the fluid flow rate on each of two samples (4 tests)

test 1: cut fluid flow in half and tip pressure at 5 psi test 2: cut fluid flow in half and tip pressure at 10 psi test 3: fluid flow open full and tip pressure at 5 psi test 4: fluid flow open full and tip pressure at 10 psi

All results seem a bit rough. I left them to dry overnight and will sand to 400 followed by 3 coats of kem aqua lacquer tommorow.

Can anybody tell me why the results are not smooth and what I should change to get better results. ( I need to get this cabinet done this week - before the guys come to put the granite down on it.)

When I get to the real cabinet I intend to use an oil based glaze to color it. I think the spray schedule should be:

seal with shellac put on glaze seal with shellac one coat of Kem Aqua sealer (needed?) three coats of Kem Aqua lacquer

Does anybody have any experience with mixing Kem Aqua and shellac (Zinzer )

Len

[B A R R Y]

Are you laying down a full, wet coat?

When I switched from NC to water-base lacquer, it took a bit for me to get used to how much more of a coat the water based product needed. The first time I got it right, I thought I ruined the piece. Luckily, I let it dry, and it looked fantastic.

[Eric Yancey]

I agree with Barry, it needs to go down pretty wet. Also, be careful of going back over a partially dry coat. The stuff dries fairly quickly so the edges need to stay wet as you're spraying. I've had issues where I was doing a set of doors and after I finished, I noticed the first door had an edge that was a little light. So I tried to touch it up and the first coat had already dried to the point where the two would not blend (for lack of better term).

Also, you mentioned shellac based Zinzer. I used that stuff almost exclusively for my white finishes. Here is a typical schedule:

Sand to 320 Zinzer shellac-based primer (white) Sand with 320 Zinzer shellac-based primer (white) Sand with 320 One coat of kem aqua tinted Dry for 2-4 hours at least

2nd coat of kem aqua tinted

I'm using a Fuji 3 stage HVLP so I can't necessarily advise on your sprayer setup.

Good luck!

Eric