Water based Finish

[Phil Goodson]

On rare occasions I see an instrument for sale with the designation "water based finish".
I'm not sure what the implications are.
Why are water based finishes not more common?

[amowry]

I would like waterbased finishes to work well, as they have a number of benefits, including the environmental aspect. I've experimented with many different ones, and while I feel that they have been "pretty good" for a number of years now, I was never able to find one that I was truly pleased with for instruments. Many suffer from some degree of bluish cast, which over a sunburst in sunlight looks bad. Even if they aren't blue (the ones with no acrylic typically aren't blue), the clarity often isn't 100%. This seems to me to result from overspray that isn't redissolved with subsequent coats.

The above issues might not be problematic with natural wood finishes, but with darker dyed wood, that become quite apparent, especially in areas like around neck joints where it's tricky to keep the finish very thin.

Other issues with waterbase can include microbubbles, poor adhesion, bleeding of dye into the finish...

Again, I'd like them to work well, but so far...

[Tavy]

EnduroVar is a water based finish that IMO works very well, it's not a "selling point" though... in fact I don't think anyone has ever asked me what finish I use. There's no blueish cast - in fact a yellow cast similar to shellac. However, there no question that water based finishes don't make the wood "pop" as well as oil based ones, just something weird going on to do with the way they adhere to the wood I guess.

[sunburst]

There was a quote. I can't remember who said it or the exact words, but it was something like: 'the main ingredient in water-born finish is wishful thinking'.

(Actually, water-born is a better term than water-based. There are co-solvents involved, and it gets a little more complicated than I fully comprehend, so I wouldn't try to explain it.)

As for the amber color in some of the finishes, it is sometimes added color to counteract the bluish tint of water-born finishes.
Like many others, I wish the results from water-born finishes were consistently excellent, but so far, it seems that they just aren't.

[Steve Sorensen]

Every water based varnish that I've tried was a Tone-killer.

The difference is a pronounced "mushiness" in response compared to old school oil varnish and shellac.

If you are looking to deaden or flatten the responsiveness of a top or back (as on a hollow-bodied electric) Endurovar type finishes might be a tool to try.

Steve

[Bernie Daniel]

Every water based varnish that I've tried was a Tone-killer.

The difference is a pronounced "mushiness" in response compared to old school oil varnish and shellac.

If you are looking to deaden or flatten the responsiveness of a top or back (as on a hollow-bodied electric) Endurovar type finishes might be a tool to try.

Steve

The tone killer properties and appearance issues are curious. Based on the information I got from a flooring company we worked with some years ago the water-based two part acrylic polyurethane floor finishes are lighter/clearer amd "natural looking" in appearance and provide a more transparent covering than oil based products? And of course it dries much fasted and has less odor than oil-based polyurethane. The downside is this product is close to two times the cost of the oil-based finshes.

So based on this advice we had this product (Bona Traffic water borne 2-part polyurethane) applied to oak flooring in almost the whole first floor of the house (kitchen, dining room, living room, great room, main stairs, and hallways) about 5 years ago. It is working out very well -- it is very clear and very very hard. These would seem to be properties what would be ideal for an instrument finish but from the comments of those here who have tired them it seems not.

Good to know anyway.

[amowry]

I didn't find any adverse affects on sound with waterbase, as long as I kept it thin, typically around 0.003" after buffing.

I would say that urethane-based waterbase is plenty clear if brushed/mopped on or sprayed on a single flat surface, but the problem with instruments is that there are so many opposing surfaces, so when you spray one you always get some overspray on adjacent surfaces. If the overspray isn't redissolved in the next coat, you get increasing opaqueness with each coat. Something like lacquer dissolves the overspray so you end up with a single uniform film that is super clear.

I actually tested a waterbase Bona floor product (Bona Mega) once because a well-known guitar builder uses it and highly recommends it. However, it was one of the worst that I found in terms of overspray being visible as "dust" in the final film. I'm sure it looks great if it's brushed.

If you have bolt-on necks the problem of overspray around the neck area is eliminated. However that's not as common in the mandolin world...

[amowry]

By the way, my shop floor is finished with old KTM-9, which I had leftover from testing (I have a lot of half-used gallons of finishes) and mopped onto the floor when we moved in. It's held up pretty up pretty well for ten years.

[tonydxn]

I've been using water-based acrylic for years and have had no serious problems with it. My workshop is in my house and I'm just not equipped to deal with strong-smelling fumes and inflammable solvents. Tavy is right that water-based finishes don't make the wood 'pop' - but I found a way round that. I buy a spray can of clear lacquer which is sold for spraying over metallic paints on cars and is acrylic based. One coat of that to start with and the wood 'pops' all right. Water-based acrylic goes on top of it with no problems.

[Bob Clark]

Weren't Rolfe and Jenny at Phoenix using a water-borne varnish for their finishes? They look and sound great, and I haven't heard of any finish longevity problems. Too bad they closed shop. They had a long list of innovations.

[sunburst]

Weren't Rolfe and Jenny at Phoenix using a water-borne varnish for their finishes?...

Yes, and they got the some of the best looking results of anyone that I know of.

[peter.coombe]

Yep, they were using Target Coatings EM2000 which is a water born alkyd resin varnish. Alkyd varnishes are usually oil varnishes so it is really an oil varnish emulsion in water. I use it, brush it on, and get excellent results. No blue haze, and I have measured the final thickness at 0.003". Sprayed nitro was 0.007". I think "tone killing" properties are more related to the thickness of the finish rather than the actual product. Excellent results requires practice, and I am still learning. It certainly does not kill the tone.

[amowry]

Yep, I wholeheartedly agree that thickness matters more than the material. EM2000 was one of the best that I tried, to be sure. I believe it’s what Rolfe and Jenny were using the last few years. I can imagine that when brushed on it would be the bees knees

I guess I should have qualified in my initial post that all of my experience with waterbase (except my floor) has been with spraying.

[Marty Jacobson]

Clarity is definitely a challenge with waterbased finishes.
There are waterbased lacquers from Target and General which offer 100% burn-in. I don't think burn-in is the only factor, it's more of a technique shift, and very few have perfected the art of working with waterbased finishes. We have thousands of years of experience working with shellac and lacquer, and dozens working with water based finishes.

[peter.coombe]

Yep, I agree. Techniques with lacquer are very well known, tried and proven, and French polish has been around for centuries. Some of todays water born products are very good if you can get the technique right. That takes time and practice. They are different.

[Phil Goodson]

Are there any long term issues? If you do a water based finish and it looks good, do you expect it to hold up and look good in years and decades??

[peter.coombe]

Are there any long term issues? If you do a water based finish and it looks good, do you expect it to hold up and look good in years and decades??

For me there has been nothing to worry about so far. I have had mandolins in for refrets finished with EM2000 or it's earlier versions up to about 18 years old and they are fine. Alkyd varnishes have been around since the 1920's so the chemistry is very old and I would be surprised if the water born chemical magic they do makes much or any difference. The polymerization process is still the same.

[Marty Jacobson]

Seconded. These are tough finishes. I don't use Enduro-Var anymore, but it was a result of finish development intended for basketball court flooring. I have three kids ages 8-12 who use a maple kitchen table with this varnish on it to do their homework on every day. Some light wear, but no scratches and definitely no telegraphed handwriting like I remember seeing all over my parent's kitchen table when I was a kid.

[Steve Sorensen]

I think Marty's observation about the intended purpose of the finish is important.

And, I think it is no accident that Andrew used his supply of KTM-9 for his shop floor.

Basketball courts, shop floors, and musical instruments have very different structures for very different objectives.

To my ear, the resilient, extra hard, plastic nature of Enduro-Var and EM-2000 were almost immediately apparent in the tap and sanding tone while finishing test tops and instruments. That difference was striking in the finished instruments.

In fact, the result reminded me of a test I did where I soaked curly redwood with thin superglue in an attempt to increase stability.
That didn't work out so well for the tone of the instrument either.

In both cases, my fix was to re-top, strip the back and sides, and then re-finish with TruOil sealer and Shellac French polish.

Again, the difference was striking . . . in that instruments I thought were dead were able to get back in the zone and live again.

For me, these finishes, like wipe on Poly, now are something I would use for entry level and kid-friendly instruments where the combination of quick, easy application, and toughness, are high on the list of desired objectives.

Steve

[peter.coombe]

To my ear, the resilient, extra hard, plastic nature of Enduro-Var and EM-2000 were almost immediately apparent in the tap and sanding tone while finishing test tops and instruments. That difference was striking in the finished instruments.

Firstly EM2000 is not a hard tough finish. It is relatively soft in comparison to lacquer KTM-9, and Enduro-var, so I don't know where you got that idea from. It tends to dent (a bit too easily) rather than scratch and is very flexible. I have peeled it off masking tape and you can fold it in half and it won't crack. I have done measurements of mandolin and guitar modes of vibration and find that before and after the EM2000 finish there is no difference in the frequencies, so the finish is not affecting the way the top vibrates. I strongly disagree with what you just said. It might apply to Enduro-var, or KTM-9, but not to EM2000. EM2000 has an entirely different chemistry, it is not a polyurethane. I have tried Enduro-var, but never used it on an instrument.

[Bernie Daniel]

....We have thousands of years of experience working with shellac and lacquer, and dozens working with water based finishes.

True for shellac but probably not lacquer?

[Steve Sorensen]

Peter,

I realized this morning, the two I tested were Enduro-Var and KTM-9, not EM2000. Came back to make that edit, but too late.

I have not tried EM2000.

Sorry for the mix-up.

Steve

[Marty Jacobson]

I think Marty's observation about the intended purpose of the finish is important.

And, I think it is no accident that Andrew used his supply of KTM-9 for his shop floor.

Basketball courts, shop floors, and musical instruments have very different structures for very different objectives.

To my ear, the resilient, extra hard, plastic nature of Enduro-Var and EM-2000 were almost immediately apparent in the tap and sanding tone while finishing test tops and instruments. That difference was striking in the finished instruments.

In fact, the result reminded me of a test I did where I soaked curly redwood with thin superglue in an attempt to increase stability.
That didn't work out so well for the tone of the instrument either.

In both cases, my fix was to re-top, strip the back and sides, and then re-finish with TruOil sealer and Shellac French polish.

Again, the difference was striking . . . in that instruments I thought were dead were able to get back in the zone and live again.

For me, these finishes, like wipe on Poly, now are something I would use for entry level and kid-friendly instruments where the combination of quick, easy application, and toughness, are high on the list of desired objectives.

Steve

I had a French polished mandolin, sent it to the customer, and then some finish issues occurred (imprinting) due to shipping the instrument too soon.
I got the instrument back, re-finished with a gym floor finish, and sent it back to the customer. Neither of us could hear a difference in the tone.
Not disagreeing with you Steve, just adding another data point to this mess we call Life. :-)

[bpatrick]

I have had good success in the past with KTM-9, General Finishes Waterbased Top Coat, and Target EM6000. Of these 3, I might lean more towards the General Finishes. In all cases, I have not noticed a disturbance in the acoustic force. I strive for thin as possible finishes. I love a varnish/shellac finish but that's just not going to work for many players. KTM-9 (no longer available) possibly had more bluish tint. A mandolin and 2 guitars spray finished with KTM-9 are still looking good after 13 years. The GF and EM6000 are fairly new builds so time will tell. There's is definitely a learning curve to using water based. But there's also a steep learning curve to French polishing with shellac.

Recent EM6000 finish:

[Tavy]

I had a French polished mandolin, sent it to the customer, and then some finish issues occurred (imprinting) due to shipping the instrument too soon.
I got the instrument back, re-finished with a gym floor finish, and sent it back to the customer. Neither of us could hear a difference in the tone.
Not disagreeing with you Steve, just adding another data point to this mess we call Life. :-)

+1, I would tend towards:

* TruOil, thin satin coat: sounds much the same as in the white.
* Pure shellac, rubbed coating: also much the same as in the white.
* Hard shellac with sandarac, rubbed and buffed: slight noticeable increase in highs, without loss of bass.
* EnduroVar, brushed, rubbed and buffed: much the same as in the white, can be a very slight increase in highs if taken to a very high gloss.

I don't spray, and all my finishes are thin enough that burn-through while buffing out is a constant hazard, so I can't comment on what sprayed finishes are like.

One quick thought experiment: I do notice that older instruments that are covered in "muck" can have a fair bit of sound sucked out of them. I had one through last week that had a thick fuzzy carpet of "muck" on it's top and was greatly improved in tone with a good clean. It was literally like having a piece of carpet for a top! That's an extreme case, but satin rubbed-finishes are not dissimilar to my ears, likewise instrument in the white, while hard glossy finishes are at the other end of the spectrum and tend to push out more highs and perhaps have a little more clarity assuming the finish is thin enough not to effect the vibration of the top. As ever, just my 2c...