Water-Bornes Versus Solvent-Bornes the Big Picture

A philosophical, practical, technical, ethical and political but not personal discussion of today's big split in finish formulations. August 24, 2008

Here are some thoughts I have about waterborne finishes and I was wondering if anyone else has any thoughts about these?

1. Waterbornes perform poorly in important ways.
2. They're more difficult to apply and get a good result.
3. They don't look as good as their solvent borne cousins.
4. If we use them we risk working harder to put out an inferior product.
5. So, we should not use waterbornes because they are less profitable.

Forum Responses
(Finishing Forum)
From the original questioner:
Here are a couple more thoughts:
1/2 waterbornes raises the grain. There are problems especially with oak and primers/topcoats on MDF. This makes staining/sanding of colored coats harder. There are longer dry times plus better surface prep in order to avoid fish eye etc. plus a cleaner system and environment.

Its harder to use oil based stains unless waiting a long time or sealing with de-waxed shellac but then you're waiting or using not just one but two non-water products. Slowing water based stains with propylene glycol helps but its not as easy as wiping oil or glazing with oil.

It still seems to be an open question as to whether waterbornes are generally as "durable" in terms of hardness, resistance to scratching and staining and chemicals and water.

Its hard to find waterborne that is as flat/dull as Krystal Dull which will tolerate even more flattening paste and looks dead flat (though easier to scratch and scratches are really white - but that's a contract release issue).

From contributor C:
If we dont use water-base and they continue to remove voc/haps solvents from the solvent based coating's then where do we go from there?

From the original questioner:
I like the fact that you don't fly off the handle but are thoughtful. I had actually hoped that by posting about waterbornes (negatively) I'd get some more defense of them. I know its sort of playing around although the drawbacks I mentioned are real and plagued us when we did use waterbornes.

I think the solution is to evolve the technology. To do this requires more investment in R and D. This would be driven by demand. Perhaps demand can be driven by discussion.

I used (some) waterbornes successfully: tough, beautiful, a little slower, felt nice to the touch and got around the coloring problems. We won a $60K on site finishing job in Manhattan by using waterbornes and pointing out that our (numerous) competitors would be violating the law, angering the neighbors, and causing a genuine fire hazard.

The problem is the technology is still behind so it is less profitable when you don't factor in the impact on the workers and the environment - and that's just how a lot of shops think because they're trying to stay alive.

I think the fastest way to another generation of waterbornes is market demand. I may be unreasonably optimistic but imagine if a 0.5 billion dollar prize was offered to whoever could develop waterbornes that worked just like the best solvent bornes do. So, the problem is solved (hopefully) and that developer then takes all that money and goes into production and gets 0.1 billion every year thereafter.

That's a simplistic scenario but you can see what I'm driving at. I think the way forward is to stimulate demand. As you mention, if HAPs /VOCs are coming out anyway why should we wait? What are your thoughts?

From contributor F:
You won't get much argument from me. Although water-based finishes have improved dramatically in the last ten years, I'm still not sold. I have a beef with the whole "Green" image of water based finishes too. They are not completely solvent free. Then most people clean up they head straight to the sink, flushing all the chemicals down the drain. At least with solvent base the majority of waste is recycled.

From contributor D:
I agree with much of what's been said. I spray WB almost exclusively, and have for about five years now. For the applications I've used it on some have been very successful, others not so much.

After reading the WB article in Woodshop News recently I was actually dismayed at how negatively they made WB finishes sound. The article, in my opinion, exaggerated every negative of WB finishes, making it seem as if with solvent based there were never any problems or learning curves. It's this kind of negative stigma combined with the lack of real will on the part of the finishing companies that have kept WB from being more successful.

I do believe WB finishes are the way of the future, but like so many things, (lead in paint and gasoline, asbestos for insulation, etc. etc.) solvents will stay prevalent because they are very profitable, until there is a real outcry from the public. Considering most of the public does not interact with finishes, well it's probably going to be awhile.

From contributor P:
You're probably right, but so what? Not sure who you're preaching to here. Most of the finishers probably already know this, and the manufacturers definitely do.

It's not logical to leave the safety factor off your list, because it is a big deal to the people who don't want to work in a cloud of toxic mist, or exhaust it out into the world. I agree with Contributor D about the Woodshop News articles. Flexner comes off as a little close-minded about water-based to me, (but maybe a little less so since his book?), so I'm not sure he was the right guy to write that article. The other guy says "nobody" is investing in R and D for WB finishes. I think the guys at Target, Fuhr, MLC and virtually all of the floor finish companies would disagree.

From contributor K:
I agree WBs are just not ready for "primetime". We tried them for a while but ran into the same problems you mentioned. We were just not happy with the results, at all. Specifically, Target's product just didn't even come close to the look and feel of ILVA's polyester and acrylic urethane that we now use. Solvent based products are just so much easier to use and get excellent results. We happily went back to solvent-based products and have never looked back.

From the original questioner:
I agree with all of the posts. Perhaps the problem has as much to do with political will as anything else.

I also agree that more "hard science" on waterborne testing should be done to at least separate the wheat from the chaff. A possible spin off benefit might be that some shops could start to sell the "green" bit to clients who are becoming increasingly aware of how their lifestyle impacts their health (food additives, out-gassing furniture and building products etc.).

We did have some clients who were willing to pay more and this covered our costs. Perhaps if a shop could go to the one, definitive forum and then get a good sense of what's involved in spraying waterbornes they would be motivated to try it, assess the extra costs and then go to their client base and try to sell it at a premium to cover the costs.

Contributor P - I'm not preaching at all and I disagree that most finishers are aware of all the issues waterbornes involve. I'll wager that most finishers have little experience with waterbornes and certainly haven't taken the time to do their own comprehensive testing.

From contributor I:
While many of the solvent finishes do look better than many WB's, there are also times when the WB's outshine their counterparts. For example, take a maple door and stain it with an oil based stain and watch it get all blotchy. Then take an identical door and spray it with ICA's, CAN and WB stain and notice how uniform the color is and how it makes the whole door look more professional.

Never again will my company use an oil stain on any close grained wood and we are highly unlikely to use it on a porous wood either. As far as the topcoats, we have found that we can add toners, pigments and dyes to the WB topcoats that help us achieve effects that while possible with solvent coatings, give less issues with adhesion and finish failure than the solvents do.

About eight years ago we switched to WB and gave it a shot for about five years and then hit a wall where we ended up going back to solvents but we have since re-trained ourselves on WB's and are back using them as much as ever.

From contributor R:
I use both WB and solvent. I worked in Southern CA when the SCAQMD came into being. I have used WB stains since the 1980's and still use them today. I also use solvent borne coatings and will continue to do so until there is a product that does a better job.

I have tested WB coatings for at least fifteen years and have done a few large architectural jobs using them. The health hazards of WB coatings are the same as solvent borne and those that use hardeners are even more dangerous. That said a good respirator works great for both products.

Most large jobs specify what type of finish is to be used. A professional finisher must be able to apply what is specified. AWI does not rate WB finishes too highly also which is why they are not used on many high-end jobs.

(TR-3/OP-3 Water Reducible Lacquers contain fewer organic chemicals, and are not in general air pollutants. However, the clarity of water-reduced finishes is sometimes less than that of solvent-based finishing systems. This in part is caused by "microfoam" which develops in the water-based finishes.)