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Hi All
8 months ago Charles Fox told me he was generally satisfied with USL.  Most of my stuff goes to Addam but I used USL on several and they looked great at the time.  I just checked back with him recently and for what it's worth, here's an update. 
Terry

Hi Terry,

Glad to hear that your work is going well.  I've abandoned waterborne finishes and returned to good old, tried and true, nitro.  Although I could do a beautiful job with USL, it didn't stay beautiful long-term.  Shrinkage continued and after a year or so the pores returned and the originally mirror-smooth surface became coarsely textured.  Nitro isn't as rock-hard tough as polyester or polyurethane but it's easily the most forgiving and visually satisfying finish for guitars.

Happy holidays!

Regards,

Charles          ;           ;   

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Ahh, yes. Another one bites the dust... Let's see...Doolin, now Fox...both highly experienced guitar makers with a lot of finished guitars under their belts.

And you can have the best of both worlds if you like...polyester under coats and nitro top coats...and if you epoxy seal, you'll never get the sinking into the grain problem that you get with all nitro or water borne build and buff.

Ok, so I just bought a quart of KTM-9 and will be spraying when the weather warms. If you pore fill with epoxy, isn't that supposed to help prevent these problems? Mike Doolin mentions on the LMI site that there is very low shrinkage, so I'm curious what the finish looks like after one year. I'm sure the pros don't like any, but for a guy like me who gives away every guitar he builds, the trade-off between a little shrinkage and the safety of spraying water based finish is an easy decision. Does anybody have any pics of what the finish looks like after a year?

     

Charles was talking about Target USL. I've got several epoxy filled KTM9
guitars that are several years old and are still smooth. The oldest USL one I
have is about 1 year. Not much shrinkage that I could see but both dulled
out some compared to how they looked when first buffed out. I'd say you'll
be fine with KTM9 for the body but you might want to look at something
else for the neck. I had a couple of necks get gummy with KTM9.
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

It has been a while since I used USL.(2004 was the last I believe) I use KTM9 for probably have my instruments and have had no shrinkage issue and have several that are 3 years old now.

When you read a review or comment on waterborne, it has been my experience that the defect mentioned are all most always in comparison to nitrocellulose lacquer. For good reason I guess as nitro has been the standard for generations and then some. But you have to keep in mind that they are not like finishes. Just as Shellac has different attributes than a spirit varnish, waterborne acrylic lacquer has different attributes than
nitrocellulose lacquer. A long time finisher will tend to be much more critical of waterborne. Due in no small manner to the fact that nitro's attributes are well proven.

I can in no way discounts those opinions of builder that state that nitro out performs waterborne finish in hardness and long term durability, because they are right. However the newer generations of waterborne acrylic finishes have come a long way and do make a fine guitar finish.

Can they compete with the solvent based finishes an the solvent based best attributes. No. However they whole point in a waterborne is to provide a finish that is environmentally friendly and non toxic that will provide a suitable instrument finish.

So it boils down to why you are thinking about using a waterborne. Or any finish for that mater

[QUOTE=Terence Kennedy] ....... Shrinkage continued and after a year or so the pores returned and the originally mirror-smooth surface became coarsely textured......[/QUOTE]

This sounds more like a pore filling problem than a water based finish problem.

Am I missing something?

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

I think that there is not enough development going in to watebased finish for guitar use. Most waterbased finish are fine enough for furnuture and wood projects. I use them for such with little problems. But when it comes to guitars there becomes problems because of expansion and contraction thats not always a big problem with lets say a table top. Also i don't believe the developer of such products really had palns for use on such exotic woods like rosewoods and others that are curently used in guitar building.

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Guitars, guitars and more guitars.

The real problem is not expansion and contraction...furniture does that too...but most furniture just sits there and the owners don't freak at slight imperfections.   Rather what we are up against is the incredibly high standards set by the guitar manufacturers like Martin, Collings, Taylor, etc. There is no other industry that holds finishers to such nearly impossible ideals of perfect mirror surface, toughness, and thinness.   

SO TRUE

And no other product or use has the owner holding onto the item, tightly, with often sweaty hands, in every imaginable condition from very cold, to very hot, and from very humid to very dry. And we hold onto the item(especially the neck) for 5 or more minutes at a time before a short break, and then repeat, for hours on end. Then add to the equation that there is an endless variation in humans' body chemistry. What holds up fine to you and me may completely go bad under the next fella's hands. Let me rephrase that from experience with every imaginable waterborne; the next guy WILL melt it...

Absolutely no other item gets used this way.

There is a ton of development going on in waterbornes, as there is a huge demand for it. And yes, oily exotic woods are part of that. But there's no denying that they just can't get it -there- yet.

Some looked great, and some combinations were outright beautiful(Target's 9000 series over their Hybrid varnish was da bomb to my eye)and the pore shrinkage could be managed by use a filler that didn't shrink, but we're not talking shrinking back into the pores, but the surface itself shrinking; I had sample sprayed on glass that would lose a good bit of their gloss within a year. Looked at closely under magnification, the surface would be quite rough. Buff it out, and within days, we could see it returning back to its rough(er) state. It simply isn't 100% stable.

Is it really the manuafacturers or the demands of the people buying them. I myself prefer a satin finish on acoustics but I gotta have a mirror glossy finish on my flametop les paul and Quilted carvin guitars. Just wouldn't look good in my opinion and probably many others...Mike

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Guitars, guitars and more guitars.

We're between the proverbial rock and a hard place.   The customers could give a lesser you-know-what what we use as long as we deliver the results, and the results can be delivered via nitro (as long as you don't look long term) or the various poly finishes, and all of that requires using a real spray booth.   

The demand for high quality waterborne finishes that would be up to the quality and feature set found with a good nitro or poly job is a request from small shop luthiers who may make up .002% of the finish market. The big demand for waterbornes is from commercial kitchen cabinet, pre-finished flooring, and your garden variety Ethan Allen level furniture makers with a smattering from the hardwood floor finishers who sand and finish floors in situ.   Waterbornes are good enough...kind of...for the real market where VOC issues are a big deal.

So where's the money?   Not on waterbornes.   Not when you've got UV cure polyurethanes and polyesters that satisfy VOC regulations and can be done in mere days. Any improvements in waterbornes will not be driven by the guitar industry; they will be side scatter from the demands from other industries.   The major guitar manufacturers who drive the cutting edge of the clear finish industry leaders like McFadden are quite satisfied with what they have, and yes, it could even be better. But the improvements now are in delivery of the UV cured products via robotic or electrostatic spraying as both Martin and Taylor are doing.   

Y'all might want to seriously consider doing modified French polish over carefully applied and sanded epoxy filler or use varnish that way if you want a relatively safe home applied finish. From what I've seen, FP is likely to be as durable as any waterborne I've experienced; varnish is even more so; and both are more beautiful.

When the yacht industry starts to use waterborne varnishes, that's when to give the whole thing a serious look again...

Since I do this more in the hobby stage and i can't spray in my home shop and because i have no room at all for a proper spray booth setup my plans are probably to learn the french polish method. When i have tried to spray no matter how hard i tried to ventilate, the odor overwelmed the house and even the neighbors complained. And when it comes to waterbourne finishes they are no safer on the lungs then other types of finishes. I have seen people spray this stuff without resporators like it was safe to breath. this stuff is still loaded with chemicals.

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Guitars, guitars and more guitars.

Mike, you just hit a very important point...waterbornes are not safe to spray in a jury-rigged environment. The aerosols are bad for you whether it's water or lacquer solvent that's bringing them into your lungs.

Why not simply farm out the work to a specialist?   Many of the top-dollar luthiers do, and the cost is just built into the final price of the guitars. The work is also warranted.

I'm amazed by what hobby and amateur luthiers see as valid jobs to farm out (neck making, for instance) while wanting to do the hardest, most environmentally and health sensitive, and most finicky of all jobs at home...finish work. There's a strange disconnect from reality here at the OLF.   I don't get it.

Well if you read my previous post in the cnc post I. I was the one who made the big stink about using cnc necks in the first place. I want to learn how to make all the wooden parts including necks and I would also like to be able to apply a decent acceptable finish on my own. And in my situation it seems that a french polish would be the most safe and best for what i want to do. If in the future there was demand for my product I would have no problem farming out finishes if i was on a time constrant. Mike

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Guitars, guitars and more guitars.

Rick Turner said...

The real problem is not expansion and contraction...furniture does that too...but most furniture just sits there and the owners don't freak at slight imperfections.   Rather what we are up against is the incredibly high standards set by the guitar manufacturers like Martin, Collings, Taylor, etc. There is no other industry that holds finishers to such nearly impossible ideals of perfect mirror surface, toughness, and thinness.   

I would say that is not entirely true.  If you have ever finished or refinished a period piece, applying a french polish on a tea table or queen anne lowboy for example, you will definitely run into some of the same challenges.  For what its worth, I will always seal the piece with shellac first, then build up with a urethane based filler, like the EM8800 filler from target, and make sure I have a dead flat surface that won't shrink before applying the USL.  I have furniture finishes that have endured well from USL.  Time will tell on my guitar...

 

Heres a couple of pics that illustrate the problem I see with Colortone. IN the first photo, it appears that shrinkage on the spruce top has created small ridge lines.  This instrument was finished some two months ago.  The second photo is walnut on an instrument finished 6 months ago.  It looks like the pores opened - like they had never been filled.  Neither of these instruments exhibited these problems just after they were finished, but appeared about a month after.  I don't have facilities for spraying nitro, so only other alternative is french polish.

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A higher purpose for wood.
Rich Smith
Issaquah, WA

[QUOTE=mgcain]

Rick Turner said...

The real problem is not expansion and contraction...furniture does that too...but most furniture just sits there and the owners don't freak at slight imperfections.   Rather what we are up against is the incredibly high standards set by the guitar manufacturers like Martin, Collings, Taylor, etc. There is no other industry that holds finishers to such nearly impossible ideals of perfect mirror surface, toughness, and thinness.   <!-- Signature -->

I would say that is not entirely true.  If you have ever finished or refinished a period piece, applying a french polish on a tea table or queen anne lowboy for example, you will definitely run into some of the same challenges.  For what its worth, I will always seal the piece with shellac first, then build up with a urethane based filler, like the EM8800 filler from target, and make sure I have a dead flat surface that won't shrink before applying the USL.  I have furniture finishes that have endured well from USL.  Time will tell on my guitar...

 

[/QUOTE]
You also need to consider that the guitar body is made of thin stock thats only finished on one side making it more susceptible to effects of humidity then let say a kitchen table top. And the woods on a guitar body are under tension and movement at all times. So the finish needs to be somewhat flexable. A table is not. I finish the top's and underside of furnuture projects to help repel the problems of humidity. You cant do that to a acoustic guitar.

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Guitars, guitars and more guitars.

Waterborne acrylic lacquers have "NO" volatile oder. The only smell is the solids them self and maybe a retarder. That is so little I can't see how some one 15' away would even know your spraying

On the lung safety issue Waterbornes are nontoxic. It may be possible for solids to build up in your lung but they are not know to cause silicosus and are not carcinogens. Plus you would have to be not wearing a simple respirator to have this problem and that just is not smart anyway. At least the ones we use So I would have to say that Waterborne finishes are far safer to the lungs than any solvent based finish. I can prove this via the MSDS. This statement is very reminiscent of the statement that CA was nasty toxic. Just not true.

Taking Rick's advice to heart, is there anyone doing custom finishing on the East Coast? (I am in northern Virginia). It may well be that as long as I am packing and shipping, sending it to California may not be much more involved than sending to an adjacent state.
Thanks in advance, Jon

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In Markham,Virginia

Hoo boy...

On the safety issue..

It's not that they are nasty, chemically. The problem is if we were to inhale even a bit of fine airborne mist, it can an will polymerize in our lungs, and do so in a manner that our lungs can't readily rid themselves of. Scar tissue can build around this, and then....

In off gassing, they are much safer, but wet and airborne, they may even be worse than nitro and the others.

The very fact that so many think of it as non-toxic, and thus use it in very wrong environments with minimal to no protection, makes them MORE dangerous. At least with Polys and nitros, you can smell the danger...

Grumpy has it right on the safety issue - it doesn't stink, but that doesn't mean you spray without an exhaust fan and respirator.  You wouldn't drink this stuff, so don't breathe it either. 

when you talk about a spray environment for water based, you still need to exhaust the overspray, you still need to let it offgas, and you still need proper protection for your lungs.  What water based WON'T do is create a fire hazard, so you can usually do all of the above with less expensive, albeit NOT LESS EFFECTIVE, equipment, and you can sometimes get a break on your insurance. 

I spray both, depending on the job, and there are properties of both water based and solvent based that I like.  I think that given the way some states, like California, regulate the coatings, that water based products will continue to get better and better. 

Rich,

What was your finishing schedule like on the guitars you showed in the pics?  how was the wood prepped? what product was used? how many coats? what type of sealer, if any?

 

I pretty much followed the schedule published on stewmac's site.  I used Colortone grain filler (which is not very effective), Colortone sealer (at least 12 coats) followed up with Colortone top coat lacquer (12 coats).  I waited a week before polishing.  

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A higher purpose for wood.
Rich Smith
Issaquah, WA

Colortone recommends 12 coats of sealer Wow!!your finish must be near 10 mils thick