I live in cold Indiana and need to apply finish to a TV stand. I typically prefer lacquer but given the outdoor temps, I am unable to properly vent for lacquer. Any advice for spray finishing a water-based poly?
You will need some warmer temps for waterborne finishes, above 60º in many cases. The fumes aren't explosive, but they can still be bad for your health so wear a good quality organic vapor 1/2 mask. Waterborne finishes can't be thinned excessively, so check the label carefully and don't exceed what the manufacturer suggests.
I've not used a wipe on waterborne, so can't offer an opinion, I do think it would eliminate the aerosol problem so you wouldn't need a the mask. But the thinning part can be tricky. A lot of them are sold as either specifically a spray formula, or specifically a brush formula. I recently used one of the GF finishes (HP) and it suggested it be thinned no more than 10% which is the range I've seen on a couple of them. I've also used Target Coatings products, but they spray right out of the can. If the manufacturer of whatever you have has a web site, you might check there…or just try it out without thinning, and then thin a little at a time. Once you get it to spray as you want, then watch and see if the finish sets up properly.
Forgot to mention: don't forget the grain raising issue with waterborne finishes. After the first coat the wood will "whisker" and feel very rough. Not to worry, juts let the first coat set up (apply a second if you want), and then smooth it with a light sanding. At that point the wood is sealed, and subsequent coats should go on without the grain being raised.
Target coatings has outstanding waterborne finishes. I stopped using pre-cat lacquer due to concerns with blowing myself and house away, and started using waterbornes, and found Target to be the best.
Have you stained or dyed the wood? Solvent stain? Waterbornes don't like solvent stain a lot. Either give several days for complete cure, or give it a coat of dewaxed shellac. No grain raise concerns after solvent stain, since they have a binder that seals the wood. If finishing bare wood, pre wet for grain raise. Wet it down well and let sit for several minutes. Wipe the water off the surface, let dry, sand with 320 or so. No further grain raise.
I've sprayed minwax polycrylic full strength with great results. It dries fast. I've also used target coatings tinted lacquer and it dried even faster. I would still vent while separating to get some of the overspray out and wear the respirator as previously suggested.
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