What are you finishing ?. So called poly-acrylic is acrylic base with a small amount of urethane resin added. None of the water borne finishes have the same characteristics as the oil based.That doesn't mean they are not good finishes just not as labeled. Whenever spraying several thin coats are preferable to a few that are heavy.

Regards
Jerry

 

Jerry,

I'll be spraying MinWax Polyacrylic on some pine doors. On other projects, I've used a brush with poly acrylic and I know that I need 3 coats with intermediate sanding to get a smooth finish.

It's a first for me with HVLP which, I hope, will allow me to skip the sanding and spped the process. Accordingly, I'm asking lots of simple questions.

TTG

 

Hi TTG

You will still need to knock the fuzz down from the spray to get that nice finish..

I use a pad that looks like washing pad it's not sand paper or steel wool but it works very well to remove the over spray fuzz and the dust from the air blowing it and around the job.
The pad is about 8" x 8" .
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Thrifty, Though I'm not an expert on finishing, I Would think you would still need to apply 3 coats with sanding between to get a smooth finish. Spraying would be faster to apply than brushing. Have you tried a sanding sealer first then staining, if staining, then apply the poly? I've used the Min-wax spray on poly that they have in spray cans and still needed 3 coats min. Just my thoughts. I am interested in what others have to say about this also. I have been wondering about spraying with HVLP to finish my candy dispensers. The spray cans are costing me a fortune. The only benefit of using them is it dries very fast and I can put three coats on in about an hour or so. Brush on would take 3 to 4 hours a coat.

 

Hello,

After applying a natural/clear stain, I applied a layer of water based sanding sealer using my smallest nozzle and a very small needle valve opening. The sanding sealer was an Olympic product (PPG industries) that was discontinued by Lowes. Although a low viscosity product, it did seem to "gum-up" the nozzle and air jet ports on the HF HVLP gun. But, the applied finish was pretty even. The final coats (2) are with Minwax Polycrylic, which seems to work really well in this HVLP system (using smallest nozzle and small needle valve opening). Using a larger nozzle with a water based polyurethane (Olympic product) resulted in an "orange peel" finish and long drying times.

Hopefully, that might be of help.

TTG

 

Bob,

You mean those soft Scotch-brite pads?

TTG

 

HI TTG

you got it

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Thanks Thrifty. I'll keep this in mind, now I need to get a HVLP gun.

 

I thought sanding sealer went on before the stain?

 

I'm not an expert, but I do the following process, if using a stain and clear coat;

1) Sanding
2) Pre-stain conditioner (for softwoods and maple)
3) Stain
4) Sanding sealer
4.a) Light sanding
5) Clear coat (2x)
5.a) light sanding between coats

Good luck

TTG

 

Ah.. ok thanks Thrifty. Maybe it was the pre stain conditioner I was thinking of. Obviously I haven't done much finishing work.