Need help understanding waterbased/waterborne finishes

[Gator95]

Oil-based varnish technology is pretty easy to understand, as is traditional Lacquer. I'm having a MUCH harder time getting my head around many of the waterbased products, and their properties.

The explanation here: http://www.woodzone.com/articles/wood_finishes.htm says that waterbased products are essentially 'latex paint without pigment'. However, this doesn't seem quite right, since reports from people using waterbased poly indicates they are getting a coating that is much harder and more resistant to wear and blocking than a latex paint.

So in particular:

What the heck is a waterbased lacquer? Traditional lacquer is a nitrocellulose dissolved in solvent, which evaporates quickly and deposits coating on surface, and can be redissolved with the solvent. How does this work in a waterbased system??? Product example: http://www.targetcoatings.com/emtech-6000.html

What is the difference between a waterbased acrylic and a waterbased 100% acrylic latex? Is a product like the General Finishes Enduro pigmented waterbased acrylic essentally the same chemically as a latex paint? http://www.generalfinishes.com/indus...industrial.htm

From the same GF link above: What the heck is a pre-catalysed Urethane? What makes it different from a 'regular' waterbased polyurethane like this one: http://www.woodcraft.com/product.asp...0&FamilyID=756

If a waterbased polyurethane dries harder and without blocking/stickyness than a latex paint, why aren't folks dumping pigment to the WB poly to make a colored opaque furnature coating?

Could go on and on... but this is a start at least.

[cabinetman]

This subject is difficult to answer easily without going into the chemistry of each of the products. I touched on some of the highlights in THIS THREAD.

As for Target Coatings calling them "Waterbased Lacquer", checking the MSDS, there may be a small solvent percentage that allows the coating to somewhat dissolve (burn into so to speak), or act on a previously cured coat, which typifies what the properties of acetone based (lacquer thinner) lacquer does. That does not mean it is a waterbased lacquer. For the marketing it seems to appeal to many users with that terminology.

Waterbased polyurethanes can be tinted with compatible tints to create a color coating. As for hardness of the cured finish, the ratios and types of resins and co-polymers dictate its performance. Waterbased polyurethanes can be cross linked with a catalyst that basically alters the chemical properties and can improve its stability.

WB polyurethanes cure more rapidly than latex paint which may be due to the lack of pigments used, making blocking less likely.
.

[drumpriest]

Concerning EM6000, the name is descriptive of the properties of the finish rather than the specific chemistry involved. EM6000 uses an acrylic resin. There are several companies calling their finishes a water based lacquer, but EM6000 is the only one I know of that has burn-in.

Having used this product, it's really nice. It bonds well to different materials, including to nitro lacquer, which is convenient. The burn in eliminates witness lines during polishing. The dry time is about 30 minutes (give or take, based on weather), the cure time is 72 hours. It suffers only from grain raising, which is typical of water based finishes.

It's formulated to act very like nitrocellulose lacquer, but with super low VOCs. It sprays nicely.

[Gator95]

Concerning EM6000, the name is descriptive of the properties of the finish rather than the specific chemistry involved. EM6000 uses an acrylic resin. There are several companies calling their finishes a water based lacquer, but EM6000 is the only one I know of that has burn-in.

Having used this product, it's really nice. It bonds well to different materials, including to nitro lacquer, which is convenient. The burn in eliminates witness lines during polishing. The dry time is about 30 minutes (give or take, based on weather), the cure time is 72 hours. It suffers only from grain raising, which is typical of water based finishes.

It's formulated to act very like nitrocellulose lacquer, but with super low VOCs. It sprays nicely.

Have you used any pigments or colorants in the EM6000? I've got a couple of pieces I'll be doing in the near future where I'll want a very hard, opaque white or black coating. Would like a waterbased product which is spray-friendly, and drys quickly to a sandable or top-coatable finish.

Looking for alternatives to 'traditional' alkyd paints or waterbased paints like the waterbased Impervo from BM.

[pecker]

Have you used any pigments or colorants in the EM6000? I've got a couple of pieces I'll be doing in the near future where I'll want a very hard, opaque white or black coating. Would like a waterbased product which is spray-friendly, and drys quickly to a sandable or top-coatable finish.

Looking for alternatives to 'traditional' alkyd paints or waterbased paints like the waterbased Impervo from BM.

Crystalac comes in white or black, with various sheens.
http://www.mcfeelys.com/color-coats

[drumpriest]

I have not tinted EPL, I typically use an amber shellac then topcoat with the lacquer, but they have a white base for pigmented lacquering.

http://www.targetcoatings.com/shop/p...SE-291-32.html