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I use EM6000. Not a bad learning curve (just don't over spray it as bluing is an issue). I haven't used EM7000, but have heard that it doesn't allow for repair as easily down the road (doesn't burn in well). I buy my lacquer by the gallon and that will get me 3-4 guitars.... I think. I haven't really kept track of that part all too well.

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ELEVATE || Next Level Lutherie
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I can't offer much advice in the way of comparisons, but I can tell you I finished my first guitar (OM style) with a quart of em6000 and actually had to spray a few more coats than I would have if I had better technique. The new Polywhey finish that's being talked about lately builds a bit faster so I think I used half a quart or so with it. I'm having some trouble with that finish however I think it's me and not the finish. Another one I've been eyeing lately is "Enduro Water Based Lacquer" sold at homestead.

As far as the more popular finishes, I think you have listed the big three that folks seem to use.

There's also KTM-SV, which is a better option than the 9. I had chemical reactions occur where my skin touched it, as did several of my customers. I suppose it's possible that I may have done something wrong in the application process, but I don't really see what. The KTM-SV has been trouble free for me, except for some adhesion issues. Fresh dewaxed shellac from flake seemed to work as a sealer/tie coat. As well, it stays flexible even after drying, which makes me wonder about it's effect on tone. But I wonder the same thing about all finishes....

Dark or light wood?
I'm a big fan of EM6000 generally, although it is acrylic, so I'm less enamored as the wood darkens (...maybe KTM-SV, 'though I haven't tried it.) Actually, my last was mahogany & I french polished it for that reason. 7000 seems too high solids from what I hear.

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Dave
Milton, ON

I've used KTM-9 on about 40 instruments now. I have had the skin reaction with one of my customers but it fixes easily. Actually he has two of my instruments but his skin only caused "warts" on the (mostly) neck. I can paint 3-4 guitars with one quart. The finish will buff out better the longer you wait. I usually wait about a month then it will level sand and buff out in about 4 maybe 5 hours total.
I love it...

Mikey

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The Biggest Little City, Nevada
www.hammondguitars.com
I love building guitars!

I'm pretty happy with Grafted Coatings' KTM-SV now that my adhesion issues have been resolved. I'm also looking forward to hearing more about their new waterbased product (Trial 2009) which is currently being field tested. See here for details: http://www.graftedcoatings.com/t2009.html

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Cheers
Pete

Pete, what ultimately was the resolution, if I could ask??

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Dave
Milton, ON

Filippo,

Here are some comments on EM6000. I’m new to finishing so take this for what it is worth.

Quantity
I used Em6000 on my first spray finish job so I had quite a bit of learning curve going on. I ended up sanding back several times and redoing it. For quantity I went through a little less than ½ gallon. I know that sounds like a lot, but again, learning curve and sand backs. I bought a gallon. By the time you add the shipping in to the quart from Target Coatings, spending the extra and just getting a gallon makes sense. I’m glad I did.

Burn In
Once I figured out how it worked the burn it was nice. There are some witness lines I can see, but that could have been that I was doing something wrong early on. I read that you shouldn’t use mineral spirits on it when wet sanding between coats so I went to Naptha. I should have been wiping down with DNA but I didn’t in the early coats. My guess is that if I had just stuck with DNA I would have been fine. As part of the sand though fiasco (which there were many) I redid my headstock about 5 times. In the end I was brushing it on with a good flat 1” artist brush. This worked great. The key to doing this was to do a long stroke and let it level rather than trying to drop fill and level sand just a spot. I did do some drop fills and those blended in fine with no witness lines. Just make sure you coat it with DNA before you drop fill.

Blueing

In my case it is more of a purple. Let’s just say when I’m dead and gone and this guitar gets donated to the Jedi Order, Mace Windu will love it. In doors it isn’t that bad but outside it has this nice purple glow in the rosewood areas. The top is fine. This could be due to the thicker coats that must be on there based on the amount of finish I went through, but I still see it in the headstock (which I know is thin) and some of the other thinner spots.

Durability
It seems durable. I tend to scratch in the pick guard area and I’m not seeing that now. I finished the neck with it and like the feel. I glued the bridge on with a vacuum clamp and had a couple of spots of “stuff” on the membrane. The bridge went on after the top had cured for about two months but it left dents in the finish where the “stuff” was. I’m not sure if this would have happened with other finishes, but thought I’d mention it. Next time I’ll just be more careful with my technique.

Overall I like the finish. I think it was a good one to learn with. If it weren’t for the blueing (which could be technique) I think I’d stick with it. As it is now, I’m thinking of trying something else on the next one.

EM6000 here..

I've probably sprayed a hundred gallons of nitro over the years. I had to try something else. I tried KTM9 first. I really wanted to like it. The application was always a pain. I was at a workshop with Jay Lichty who suggested the Target product. I'm gonna make this short.. The EM6000 is a much easier product to work with. I'm able to lay it on at the recommended 2-4 mils with no problem at all. It dries really clear and glossy. It costs $45 a gallon instead of $32 a quart. It's recommended that it cure for 2 weeks by most luthier types. There is really good support for the product. There is even a forum that has a luthier section. I've got a half a quart of KTM9 I'll send you if you want to try it..

My 2 cents.. Michael

I really like the KTM-SV product better then the KTM9. I have no experience with other waterbornes.
Drop Laurent Brondel an email...he's using something that he really likes for some of his budget-minded instruments.
If I were going to use a waterborne, I would use the SV. I too would like to hear more about the product currently being tested. The folks at Grafted Coatings seem pretty high on it, but I have some concerns being that it has acrylic in it, which usually tells me it's going to look blue in some applications.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Dave there's a lengthy discussion of KTM-SV with particular reference to adhesion problems here: viewtopic.php?f=10101&t=29797

I managed to find a local source for a two-pack polyurethane barrier coat manufactured by Ilva, and I'm satisfied that the problems I experienced with poor adhesion of KTM-SV to shellac seal coats are now behind me.

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Cheers
Pete

Hi Filippo,

As you have likely read, I am an EM6000 guy. I have used it on quite a few guitars and at this stage find it very predictable, easy to buff, durable, and repairable. A couple of years ago I tried a General Finishes water based poly. It went on easy enough, but it just wouldn't buff out to a high gloss. I was quite disappointed with it. I have not tried any of the grafted coatings finishes. I found the biggest cause of problems with EM6000 is using old finish, and old to me is something that has been around for a half dozen months, either open or unopened. I always order a fresh gallon prior to spraying guitars, just to make sure I have really fresh lacquer. Older stuff can have finish flow and burn in issues.

Ken

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http://www.casperguitar.com

It seems one of the biggest challenges with water base finishes is finding a supplier who won't monkey with the formulations........just when you think you have it figured out, it changes.

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Formerly known as Adaboy.......

Hi Filippo,

For context, I've finished about 10 guitars total, so take my comments as an "advanced beginner".

The first several guitars were finished with KTM9, and I struggled to get the application right. Lots of orange peel, which admittedly could have been my technique. I tried warming, thinning slightly with DA *worked better), but found it a challenge to lay it on with the appropriate thickness and consistency. Final product was pretty good, once leveling and buffing was done.

I moved over to EM6000 when the KTM9 was unavailable due to supply issues. I prefer EM6000. I find it easier to apply, and the finish is comparable, if a little better, after levelling and buffing. No bluing from what I can tell. Finally, one thing I did find with EM6000 is that it didn't like to be thinned with even a little DA. I thin it with just a little warm water.

YMMV.

Good luck.

Pete Brown Said
I managed to find a local source for a two-pack polyurethane barrier coat manufactured by Ilva, and I'm satisfied that the problems I experienced with poor adhesion of KTM-SV to shellac seal coats are now behind me.

Pete, I checked this out on ILVA's site but they had little info. Can you shed some light on it for me?
I assume you use:
TF-25 resin
TV-19 hardener
TZ-35 thinner

Do you apply the TF-25 over epoxy filler? Z-poxy or other?

How do you apply it? Spray, brush, or pad on?

Level sand before spraying KTM-SV?

Thanks for any help!!!

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Joe Beaver
Maker of Sawdust

Joe, I found a similar Ilva product locally, packaged as TF23, although TF25 is what I really wanted after reading Randy Muth's advice. The mix ratio is different, but supposedly it's a comparable material. Stick with the TF25 if you can find it.

I leave a thin layer of epoxy on the back, sides and neck after the final session of pore filling and sanding, so the sealer goes over the epoxy except for the soundboard which is bare wood. Before I apply the sealer, I wipe down the cured epoxy with a 50/50 mix of water and DA in case there's any amine blush present. I spray two coats, two hours apart, although I recall that Randy applies it with a foam brush. If the first of your KTM-SV top coats is applied within a four hour window, there should be no need to sand the sealer (unless you have serious runs I guess). A light scuff with a Scotchbrite pad should remove any dust nibs in preparation for the top-coats.

Here's a link to the product data sheet for Ilva TF25: http://www.whistlingfishsoftware.com.au/Downloads/IlvaTF25.pdf

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Cheers
Pete

Thank you Pete. Sounds like a plan!

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Joe Beaver
Maker of Sawdust

For the record, I've sprayed KTM-SV straight over ZPoxy with no issues. On the top, I sprayed 2 coats of SealKote and sprayed KTM-SV straight over that. I didn't sand the SealKote as I didn't want to chance sanding through. Probably no a big deal on spruce but might be on the edge of the binding, rosette, etc.

The new KTM-10 product (still a trial) seems to be just asa clear as SV but it seems to cur/dry fine on an oily wood (or at least it cured fine on the cocobolo I tested on for whatever that is worth).

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Formerly known as Adaboy.......

Darryl,
That's sounds pretty easy. Did you do that over oily wood? My current builders are walnut, koa and Bolivian rosewood. (not oily to oily) I'm not familiar with sealcoat. Is that the zinnser dewaxed shellac product?

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Joe Beaver
Maker of Sawdust

Yes, the Zinser product. The back and side wood was East Indian Rosewood. Don't sand the last thin coat of zpoxy if you need a good seal.

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Formerly known as Adaboy.......

Thanks Darryl,
I do use epoxy filler. I think I'll try that befor I spend the bucks on the Ilva product. With my luck the KTM10 will come along and be superior and not need the sealer.

Thanks for your help!!!

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Joe Beaver
Maker of Sawdust