Waterborne Finishes Versus Solventborne Conversion Varnishes

Comparing the characteristics of solventborne and waterborne finishes, with some tips on success with waterbornes. June 30, 2009

I am looking to start using waterborne finishes, clear and pigmented, for kitchen, bath and built ins. I have been using CV from ML Campbell. Who could give honest pros and cons of using the waterborne products? I am under the impression that these products would be healthier to use than solvent based, but what will I be giving up?

Forum Responses
(Finishing Forum)
From contributor B:
I don't have a lot of experience with solvent finishes, but have been using Target Coatings waterbornes for about three years now. From my experience I can say there are a few more steps to waterborne as far as sanding is concerned due to the obvious grain raising. Dry time is slightly longer, usually about 20 minutes between coats in my region. Curing is faster, usually 3-4 days before you could buff or polish.

From contributor C:
I committed to using waterborne (FUHR) when I started my shop about five years ago. It seems to me the single biggest issue would be the adhesion. Since I am very small I can be sure that a part is scuffed well but for a production shop you really need to be certain that your hands understand just how important this is. I was never a finisher so I learned from the ground up so to speak. I did use solvent based before but not every day.

I believed that this would pay off big someday, well still waiting for that day. I did have a job come up, a remodel kitchen about 120 miles away that I would never have picked up had it not been for my use of FUHR product. All is well I dearly love my finish from start to well finish. I know that it is a great finish and would not trade it. Dry time is wonderful the look and feel is great and no fumes to worry about. I wash up with water and use a small amount a thinner to keep the guns cleaned.

From contributor B:
Make sure you find a waterbase finish that is rated to perform like a solvent base conversion varnish (there are not a lot of options out there). There are six main categories that we compare: chemical resistance, boiling water resistance, hardness, abrasion, resistance, lacquer thinner resistance, and acetone resistance. Your supplier should be able to provide you with performance data for the waterbase product recommended. Once you find the right product, here are some typical differences:

Solvent base CV:
Odor: strong!
Health Hazard: High
Clean-up: Lacquer Thinner
Film Build: Excellent
Hardness: Excellent
Abrasion Resistance: Good
Reparability: Poor
Cold Check Resistance: okay to poor
Pot life: Limited ( about 24 hrs (2 component))
Chemical Resistance: Excellent
Water Base Finish (with CV rating)
Odor: Minimal - none
Health Hazard: Low
Clean-Up: Water
Film Build: Very Good - Excellent (overall a little less than CV)
Hardness: Very Good (overall a little less than CV)
Abrasion Resistance: Excellent (overall better than CV)
Reparability: Very Good (a lot better than CV)
Cold Check Resistance: Excellent (a lot better than CV)
Pot Life: Typically unlimited
Chemical Resistance: Very Good to Excellent (can be close to CV, but I still give a slight edge to CV).

Overall, you will find a lot of environmental advantages with water base finishes (flammability, health, odor, disposal, and clean-up). As a general rule of thumb, solvent base should give you the edge on film build and hardness, and a slight edge on chemical resistance. Besides the environmental advantages, waterbase finishes that fall into the CV performance category will give you the edge on abrasion resistance, cold check resistance, and reparability. With the right product selection, most other properties will be a wash: you will be able to obtain the same high level of water resistance, lacquer thinner resistance, and acetone resistance with water base than you can with solvent base (product specific). Just make sure you choose a water base product rated to give you the same performance properties as a CV.

From contributor B:
I am certainly no expert on this but I have acquired three years of "hard knocks experience." The first bit of advice I will offer to anyone considering switching to WB finishes is do away with any sealer other than something that is offered by the same company that makes your finish. There are too many compatibility issues. I use Fuhr products. There are many good WB finishes. On the advice of the tech people at Fuhr I quit using sanding sealer and started using only the Fuhr 380 Waterclear Varnish from start to finish. Many of the wood species donít experience grain raise since the coats are so thin. I do have to apply several coats to the more open grain woods. If you want a polished finish you can buff this product. I allow at least five days before buffing with automotive buffing and finishing compound from 3M.

The second lesson I learned the hard way. Don't sand too much. I typically sand to 180 then put on a couple of thick seal coats. I like to let it set for 48 hours before sanding, not necessary, but it works for my situation. Then sand with 320. 2 more coats in quick succession, about 20 minutes apart. If I am going to polish I usually allow to dry and scuff and apply two more coats. I get a 12" finish doing it this way. Very much like the lacquer of old without the health risks.