Waterborne lacquers

How quality measures up against other finishes. December 26, 2002

A number of posts state that waterborne does not equal the finish quality of NC lacquer. However, in going through a 1988 copy of Fine Woodworking Magazine, I noticed that three associate editors of that publication compared Oxford and Enduro to NC lacquer and found no difference. Is it possible that those who found waterbornes inferior were using substandard products?

Forum Responses
From contributor M:
There are differences between the two coatings. Water base coatings have come a long way, but they are still not the same as spraying with NC lacquers. You still have to add a little color to water base coatings to warm them up. In some cases you need a solvent based coating to act as a sealer, so the grains will not raise from the WB coatings.

From contributor A:
Got to disagree with the above.

As far as objective performance characteristics are concerned (hardness, scratch resistance, water and chemical resistance, adhesion, etc), PianoLac and some other waterbornes are far superior to NC lacquer. You don't have to take my word for it. Step boards finished with PianoLac are available for your inspection.

As to appearance, many waterbornes, even some of the new reformulated ones, have a cold, plastic look. PianoLac certainly doesn't, and I'm sure there are other waterbornes that don't impart an artificial appearance. What you do get with PianoLac is 100% DOI (depth of image). If you build up NC to a thickness suitable for a piano finish, it will amber and obscure the grain. Some think this is beautiful, but you should reserve judgment until you see what a truly clear coating looks like. Grain revealing, rather than grain "enhancement" may actually look better.

If you desire the NC look with waterborne coatings, it's easy to do without tinting. My favorite technique is to spray a thin coat of stain over the last coat of sealer, then proceed with the clear topcoat. This can result in a finish that is indistinguishable from NC lacquer.

From contributor M:

You're right that WB coatings have some advantages over the NC lacquers. They also have some disadvantages, two of which I already mentioned. Another is the reparability in future damages, in which NC coatings have the advantage because they are evaporative, and will re-flow. I am not promoting one over the other. They both have strengths and weaknesses.

I just used Fuhr 355 yesterday for the first time. I was very impressed and will be ordering it. It did not raise the grain any more than the NC I used to use. It "wets" the wood, so it casts that warm glow that you would expect with solvent based. This was my first time using my samples and I was pretty skeptical but I am sold. Easy cleanup, etc. One thing, though - you need to prep by sanding up to 220, something I never did before. Looks good so far.

From contributor D:
Here's the real deal, and since I sell neither solvent or waterborne coatings and I have no ax to grind against either, you can take this as an unbiased opinion. Waterborne topcoats can be every bit as good as solvent. The Fuhr 355 is good stuff, as are several others. I personally like the General Finishes Pro Acrylic the best at present, but that could change next week if something new comes out.

The problem with waterborne topcoats in general is the variability in weather and climate. Waterbornes that work well in Mississippi (with average 80% humidity) have problems with 10% humidity out here in the desert. The advantage of solvent coatings is that they have greater tolerance for changes in climate. Also, with the smorgasbord of solvents available to tailor them to local conditions, they are much more flexible in their ability to be adjusted to accommodate local conditions.

If you live where the waterborne coating manufacturer lives, chances are they can deliver to you an outstanding waterborne coating. Id look for a local manufacturer that lives in the same climate as you.

The day they invent a waterborne for sailing yachts is the day I am going to switch over.

From contributor D:
Today's that day. The first market Target Coatings got into was yachts. That's why they called their initial product Oxford Spar Varnish. Straight up, before they got into furniture finish they were into clear wood coatings for yachts.

From contributor J:
Contributor D, I would like to know the settings you use on your Astro 1.7 gravity feed for waterbased topcoats. I've tried your suggested solvent settings. 1 full turn fan, almost full open fluid, 30 lbs pressure. Including 10-15-20-25 lbs. I'm still not getting that glass flow-out. I'm using Oxfords PSL, a waterbase lac with "burn in". I've also used their flow-out additive.

From contributor D:
Are you measuring the air pressure on the gauge of the regulator with the *trigger pulled*? Also, you might want to turn the fan down a bit. Waterbornes never look good off the gun. The reason is surface tension. It's how they look the next morning that matters. Normally solvent coatings look best at birth. Waterborne about 12 hours later.

Contributor D, your comments are very interesting. I do wonder about your statement on waterborne finishes looking best about 12 hours later. It could lead some to believe that working with waterborne products takes a lot of time. I am using waterborne way up here in Minnesota. We can have humidity and temp changes that cover all the ranges you mentioned in your post. Come up here some time when it's been -15 degrees for a week and you'll think the moisture is being sucked right out of your body.

So far I'm just doing doors and millwork, and I'm not a pro. But the finish I'm using doesn't take anything near 12 hours to look very nice. Within 1 hour, the max needed to wait for recoat, with the product I use, it looks just as good as it will the next day. I have seen it take up to 15 minutes to flatten out, but that is a far cry from 12 hours. What it seems to boil down to is that if you don't apply the material, waterborne or solvent, in conditions listed on the label by the manufacturer, you run the risk of not getting the best results possible. All that being said, the advice you gave on seeking a manufacturer that is in a similar climate seems very sound. If I misunderstood your comment on 12 hours please explain further.

From contributor A:
The low humidity, high temperature problem is solved, at least as far a PianoLac is concerned. PianoLac slow is retarded version of regular PianoLac. It flows out with no orange peel, even at 10% humidity, 90 degrees. It can be blended with the regular for intermediate drying rates.

Why not just supply a retarder? Retarders tend to stay in the coating a long time, keeping it soft. PianoLac slow cures just as fast as regular. It will sand to powder 2 hours after application.

From contributor D:
Okay, so make it an hour instead of 12. What I'm trying to say is that off the gun, they look worse than they will at some future time, whatever that might be for the product you are using.

From contributor A:
Can't speak for other waterbornes, but for PianoLac, when it's dry to the touch (7-15 minutes after spraying), that's how it's going to look. When properly sprayed, it flows out with no orange peel. The Rub Effect looks and feels like it's been rubbed to satin luster, and except for the absence of scratch lines, is virtually indistinguishable from a hand-rubbed finish.

From contributor J:

I am measuring the pressure when the trigger is pulled. I have tried various fan as well as fluid settings. I lack the experience of being able to analyze the results and let them direct me to the correct adjustments. I will try your latest advice.

P.S. I am talking about a dried finish appearance.

As a spraying beginner I have been practicing with the inlet pressure measured before pulling the trigger. Is that wrong?

From contributor D:
Yes. It means nothing as it doesn't take into account the pressure drop between the regulator on the compressor and the gun. This can be a huge number. Always measure it with the trigger pulled.

From contributor R:
I would like to find a coating that would preserve the color of freshly moulded eastern red (aromatic) cedar. I have both interior and exterior applications. Any ideas? I have read that water based materials retain the color better for interior applications.

Contributor R, contact Target Coatings for their recommendation. They have some water-base finishes with high UV protection for interior and exterior use.

Contributor R, you also might want to check with Fuhr. Their 355 is great. I make custom made cedar bible boxes with it all the time with great success. I use two coats of Zinnssers seal coat 100% wax free shellac right out of the can. Then use the 355 as the topcoat. I would just make sure that the cedar was all milled about the same time. We like the red look, and it has to be freshly milled for that. If you just want the brownish look, just give it a sanding and let it set for several days before applying anything.