I'm trying to change my solvent based finishing ways, and I've recently tested several waterborne products. Iím trying the materials that my most knowledgeable friends have recommended as being the best waterborne products available. Here are my preliminary findings.
The problems I've found with most waterborne grain fillers are twofold. First, they dry way too fast. I live in Arizona, and most of these dry on one end of the board before I get to the other end. Problem two is that they shrink. This is particularly fun when you're buffing out a prize piece and the pores start showing up as your power buffer is bringing things up to a nice gloss.
But at least there is an exception to this generally pathetic performance--Famowood Trowel Grade Grain Filler. This is mostly wood flour, which I suppose is mixed with an acrylic binder. It is actually better than the solvent borne Famowood. It's applied to bare wood like joint compound is applied to drywall and then sanded off. The Famowood takes stain great and doesn't shrink. You can tint it with HULS 896's (the best way) or UTC's. Oil-based grain fillers are one of the messiest products around. The Famowood waterborne takes most of the pain out of filling grain.
Waterborne wiping stains are the weakest link. They simply don't have the punch you get from a good solvent borne wiping stain. They seem to stay right on the surface of the wood and not actually get into it. That stated, there have been improvements:
a) The best of the lot, which I found to be Dayco's new Alkyd Waterborne Stain and General Finishes' EF Wood Stains, don't raise the grain as badly as they used to. They raise the grain very little, if at all.
b) The best stay wet long enough so that you can actually wipe them. Some waterborne stains that I tried dried so quickly in my desert climate that after I sprayed them on my test panels, they set immediately. I could gain some open time by adding propylene glycol, but not much. These fast dry spray stains can be used with good effect as toners, where you simply spray the color on like thin paint. My recommendation is to stay with solvent borne wiping stains. My favorites are Mohawk's and General Finishes' Prelude. I usually use an alcohol dye stain first and then come back with a wiping stain for grain development and overall evening out. Gilsonite is a great thing and the key to many a good wiping stain. There appears to be nothing in waterborne that can remotely achieve the look of a good Gilsonite based solvent borne stain.
Waterbased topcoats are getting pretty good. A couple of the waterborne topcoats I've tried looked every bit as good as Duravar or pre-cat lacquer. And some just looked terrible. They all look terrible when you first shoot them on. The ugly milky color is bad enough, but the usual rippled surface is worse. As they dry, though, things get much better.
Two things to worry about with waterborne topcoats are film hardness and color. With one product, it took two weeks for my test panels to get to an acceptable level of hardness. I don't mean adhesion--the adhesion to the substrate was good. I mean the film itself was easily scratched by a fingernail days after initial application. Oddly, this was for a product marketed as a floor finish. The best product I tried was as hard as solvent borne conversion varnish 12 hours after application, so there are good waterborne topcoats out there.
I think the Plexiglas clarity of acrylic finishes is a downer. I like the slight amber of a conversion varnish or water white lacquer, and most of the waterbornes dry glass clear. This can be fixed with an overprint dye additive to add some color to the paint and this I highly recommend.
The waterborne is far superior to solvent based topcoats when spraying drawers. I've always used lacquer to finish my drawers and even months later, if the drawer has not been routinely opened, I can smell the telltale lacquer smell when I open the drawers. With waterborne there is no odor and that's a big plus.
Grain fillers: Famowood Trowel Grade Grain Filler rocks.
Akzo Nobel told me that one of their customers in Arizona is using waterborne products. We have the same air pollution laws as Southern California, which to my knowledge are the toughest in the nation. This shows that waterborne acceptance has been less than overwhelming, even where you'd expect it to be the strongest due to air pollution laws. At least this seems to be the case for Akzo's customers. It also seems to be true for Valspar/Lilly, since the last time I was down at my local Valspar/Lilly distributor's warehouse, there was no evidence of waterborne products being there at all.
From contributor R:
You need to try the ICA waterborne stain mix system.
A few months ago, I began spraying shellac to my utter delight. Easiest product I've ever sprayed, and always looked great from any angle. I dreaded having to shoot a WB finish over it just to get durability. Then, I purchased my first gal of NC lacquer from SW, thinned it, shot it through my shellac gun on a few test panels (walnut, cherry and maple), and decided that I would only use WB again to use up my inventory. For shear beauty of finish and ease of application, I don't think NC can be beat. I'm anxious to try the more durable products like Duravar and others. I'm not a big fan of water based products.
This increase is based on two areas. First, to enhance the dry film properties of WB urethanes, most floor finish manufacturers now recommend a two-component system over a single component sealer. This separate catalyst is added in right before application, just like a conversion varnish, and has a 24-hour pot-life. It's tough to beat a finish when you can create some type of reactivity within the film.
The second increase is with educating the end-users on how to work and apply these products. Most WB finishes have a solid content between 30 - 35%. Take that 0.3 figure and multiply by the recommended wet film thickness of 2 mls, and you can see that not much of a wear layer is left. Combine that fact with floor contractors who aggressively screen their coats with 135 pound buffers to know down the grain raise. What they don't realize is that the buffer is taking off what they just put down. These contractors were used to high solids in oil polys, which leave a much higher film build and will wear longer. Because floors are finished onsite, other considerations need to be factored into the equation. A few concerns are: homeowners want their house back, odor, multiple coats in one day, and easy clean-up.
In conclusion, every end-user should discuss with the manufacturer how to use a product for the first time. First impressions are lasting and tough to change, especially when they're bad.
The WB stains I have used I didn't like. I haven't used ICA yet, but I do want to give their polyester a try and when I do, I'll give their WB product a try. The effect I'm trying to achieve and location (exposed to water or not) determines whether I use WB products (some of which can be coated with a non-acid catalyzed solvent) or solvent products. When I'm sticking with a complete solvent system, I really like the Sherwin Williams White Water Conversion Varnish as a topcoat. But, it depends what I'm doing--the overall effect could require a different system (say a CAB-Acrylic system).
Many new types of ovens are now out for waterbornes, such as rooms with ultra dry air movement and the Prime Heat Oven. We have done tests with ICA waters. Six mill was sprayed with no flash and it was placed under the prime heat short wave halogen lamps for just under two minutes, with a two-minute cool down. Then it is ready for the next coat or the shipping box. Not bad for a waterborne with a solvent content less than seven percent.
I think waters are still getting better, and the stains are getting to the awesome point with several companies.
Bob Niemeyer, forum technical advisor
The evolution of WB's has been painfully slow, due to the prehistoric legislation that dominates our Clean Air Act. European WB technologies and daily use have driven the development of WB's here in the USA only to the extent of which state-of-the-art manufacturers are willing to: A) seek out on there own through trial and error. B) Learn how to formulate into a functioning system worthy of release to a marketplace that is reluctant to change due to the major suppliers not willing to go the extra mile to develop cutting edge WB technologies of their own. Therefore, the development of WB's is left up to vanguard companies such as Target, Lenmar, Fuhr, Basic, etc, to develop coatings that can walk all over solvent-based systems but lack the horsepower to override the companies that "Paint the World".
Essentially, what is taking place in the WB marketplace right now is the positioning of the next group of majors within the coatings industry. Akzo, SW and Chemcraft combined do not have the product background or formulating expertise of WB's compared to the above mentioned manufacturers. I state this not only for my company, but for my worthy competitors who have worked as hard as I have in the development of functional, superior water-based systems.
ICA and Akzo are advanced European firms with as much history in WB technology as Target or the rest of the above mentioned. I ask the readers of this forum to strike out on their own to discover and learn to work with the systems that are now available through United States based manufacturers. Our products are sound, functional and as user-friendly, if not more, then our EU-based competitors.
Target will be releasing a new line of stains based on hybridized linseed oil which will have a color structure based on micronized pigments, transparent oxides and a.i. dye structures.