I need to switch from solvent based spraying which I’ve done for years but the fumes and handling of solvents is just not a good idea anymore. I have resisted switching for as long as I can but it’s time. So I would appreciate your help with this. I use a Fuji 4 stage non bleeder in a dedicated spray booth with an explosion proof fan.
1) What brand of finish works best for you in achieving a flat finish/matte finish?
2) Do you thin before spraying?
3) Do you add any tint to knock down the plastic look(I’ve applied wb poly by hand over walnut and did not like the look)
4) What size needle do you use I have a 1.5 and 1.7?
5) Do you find that temperature is a factor, in winter I can get the shop between 60 and 65 degrees with heaters going.
6) Is spray pattern the same i.e. north to south with 50% overlap?
7) I have good spray technique, but is there anything particularly different in how to put down a wb finish.
I know I’ve asked a lot here so I greatly appreciate your time. I am going to take the time to get a handle with this. Thanks again!
Replies
I am not an expert nor am I highly experienced. I started spraying WB poly and shellac last summer with very little spraying experience. So, I cannot directly address your specific question. However, because (IMHO) I was pretty successful, the answers to your questions must not be very critical. I have used an inexpensive LVLP (not HVLP) spray gun with a fairly low cfm (about 7cfm) compressor. My adjustments were done by trial and error and I was able to spray Varathane WB product straight from the can. IIRC, the gun has a 1.5mm tip and I used about 25-30 psi. I got even coverage with no runs or drips. You seem to have far more experience than I do. So, I would say that you have no worries. Do a few spray panels to get the feel of it and go.
Because of the lack of color in WB poly, I make sure I have the color on the wood through stain, dye, or color shellac before applying the poly. I have not yet tried adding dye to the poly, but that is certainly doable. If you do not want the wood stained or dyed, that is probably the best way to get the oil poly look.
Other than the low odor, no fumes, and water solvent, the thing I like the best is that the WB poly dries fast enough that I can get 3 coats on easily in a day.
Water based poly on anything looks pretty bad by itself. I've only done it on floors. I always put a couple of coats of Zinsser Sealcoat on before the poly. It looks far, far better, and keeps the grain from raising.
I use a Fuji 5 sprayer and I have fallen in love with a water based product by Target Coatings. Its called Emtech 6000 (EM6000). They make a couple other water based clear coats, but this is all I've used, other than their line of paint (EM6500). I spray it with a 1.0mm tip, it doesn't need thinning, dries super fast, looks fantastic. The paint I spray with a 1.3mm tip, also with no thinning required. Clean up is quick and easy. I read a lot about their offerings online, and read lots of reviews before trying anything. Glad I did.
Target Coatings has some great finishes. They also have a water based shellac, (or did have, I don't see it on their web site.)
Be aware water based coatings don't play well with any contamination like silicone oil. This would apply more so in re-finishing, if Pledge was used prior to stripping the old finish.
If you used any silicone oil additives while spraying solvent based finishes prior, you will have contamination issues. It is very difficult to completely clean equipment of silicone oil.
My experiences with Target Coatings are very similar to those express by 'msdr'. I will definitely continue using their products.
I prepare/mix shellac using flakes and denatured alcohol and use this as a sealer without issues.
I use a Titan 95 HVLP turbine with a Fuji t95g spray gun and a 1.3 tip. No thinning and quick drying in a shop maintaining 50 to 55 F.