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Although I have never tried and probably never will, my understanding is that spraying oil based varnishes is a nightmare.

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Randy Muth
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I know that Laurent Brondel and Bruce Sexauer spray Behlen's Rockhard, and there are probably others who do as well. I'm not saying that to make argument with Randy's comment - I have not yet done any spray finishing myself, so I'm clueless. I just thought I'd mention what these guys do.

I'm looking forward to taking a close look at your finishes at the Woodstock show, Randy. I'm thinking about getting into doing spray finishes, and you make a great case for KTM-SV, so that may well be what I start out with.

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Todd Rose
Ithaca, NY

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As to the blue tint from the EM6000, it was visible on the EIR guitar I did, but not on the maple guitar. It really does depend on the light in which you look at it though. I found inside no noticeable blue tint what soever, but outside, it lots of sunlight, right away you could see the blue tint. So much so, when I presented the guitar to the owner, the very first thing his Dad said when he saw it was "It has a blue tint to it" That right there made me swear to never use the stuff again on a dark wood. I really like how if feels though and may use it on necks (mind you if the KTM-SV feels as good why bother). So I'm going to give the KTM-SV a try.

I really want to stay away from solvent based finishes so I will spray several coats of shellac (non-toxic solvent based finsih ) as a sealer then try the KTM-SV. We'll see how it goes, sounds promising, thanks Randy.

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Hi Todd,

I forgot they do spray varnish, but I believe it is a short oil varnish, not Rockhard. So it can be done. I would worry about the gun getting fouled between coats, but maybe not a problem. It will be good to see you at Woodstock.

Darryl,

Bruce and Laurent hang out at the 13th Fret, so if you're interested in spraying an oil based varnish, I would check out that forum. I've settled on what I'm using, so personally I have no interest in exploring that option.

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Randy Muth
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Hey Randy does KTM-SV melt into itself like the Emtech 6000?

Nicholas

Rod,

Hey, we tried, right? But there is no point in not admitting the facts as you see them. It has an AMAZING feel on the neck. I love it. And on light wood, no problem. But the dark stuff brings out the blue. I too am heading over to KTM-SV. Why not? Lesson learned. Stay away from acrylic on dark stuff. I am glad that you and I have correlating results so now I can simply move on.

Mike

Randy,
I'm confused as to why you use a sealer after you've pore filled. Does the KTM-SV not adhere to epoxy? Or do you sand back down to wood as part of your process and then seal. I sort of thought you could just scuff epoxy and spray right on top...is this not so?

KTM-SV does melt into itself over the time frame of application. Technically once it has fully cured it will not melt into itself just like other varnishes. However, I have had great success in doing repairs. I sand the area that needs repair with P1000 and then rub it aggressively with a paper towel dampened with lacquer thinner. I then apply the KTM-SV.

Note: Acrylic based waterbornes do not like to be wet sanded, but you can wet sand KTM-SV after a 24 hour cure. It truly is very different than any waterborne you have used. You can buff after 6 days and you will find it harder to sand and buff than EM-60000. This is because it is a harder finish.

When I pore fill with epoxy, I spread the epoxy on very thin. When I level it there may be exposed wood. This is of no concern to me because I then seal it. The sealer eliminates all potential problems for me and I trust it 100%. Also I don't epoxy my tops, so the sealer makes a good tie coat there. I don't think there is any problem with KTM-SV adhering to epoxy, and I would think epoxy is sufficient to seal the wood to prevent problems, but I REALLY like and trust the sealer. It takes me 10 minutes to put on a coat of sealer.

Also I have recently been gluing my bridges directly to the finish using medium viscosity CA glue as Rick Turner does. Rick does this with polyester finishes over the same sealer I use. I tested this with KTM-SV and it works in the same way. The key to doing this with both of these finishes is the adhesion to the wood. Rick showed that this sealer does the job of tying the finish to the wood.

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Randy Muth
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Wow! Gluing to the finish? Do you rough up the area before gluing? And, Have you ever had to remove a bridge that you glued like that?

Mike

I spray Epifanes varnish. They make a spray thinner for it. They also make accelerator and retarders for it. I use 50-50 varnish and thinner (by volume) with 10% (by weight) accelerator for the 1st three coats, and then 70-30 varnish and thinner with no accelerator on the last coat. You can re coat in 24 hours but I wait 36. I buff 48 hours after the last coat but usually wait a week. I lightly wet sand between coats , with mineral sprits and 400 grit.

Randy, I tried several varnishes including EM2000, before picking Epifanes. I like your reviews of the KTM-SV. I'm satisfied with the Epifanes, but may try some KTM-SV for a waterbased option. Don't you use a spraying schedule similar to nitro with it?

Edit: I've read the whole thread now. Epifanes varnish takes a couple hours to be tack free, and dust free, even with the accelerator. You have to wait 24 hours between coats, but it builds quickly, doesn't shrink, at least not that I can tell. I pore fill with CA or West Systems epoxy, depending on the wood, and seal with shellac. I like the "Gloss Clear Varnish", and don't care for the "Woodfinish Gloss"

I hope this answers some questions. As always YMMV

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I didn't mean to say it, but I meant what I said.
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Randy,
Thanks for all the information!

Randy and Woody, thanks for all the info!

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Formerly known as Adaboy.......

Randy,

Could I trouble you for the part number of the sealer that you use for KTM-SV? ILVA makes a lot of products, and I'd like to get the right one.

Thanks,

John

Mike, you have to rout the bridge off. That is the down side, although it is easier than it sounds. I do scuff it up a little, but Rick does not with polyester. CA glue sticks like crazy to this finish so it is probably not necessary. I just do it for insurance. It is important to clean the finish to remove any oils or buffing wax residue. I use CA solvent for that. The finish is very resistant to both CA solvent and acetone.

Woody, the spraying schedule is more like lacquer. I recoat every 1.5 hours.

John, Camger sells it as polyurethane wash coat and it has three components: resin, hardener and thinner.

resin: TF-25
hardener: TV-19
thinner: TZ-35

I buy the thinner by the gallon (lasts forever), the hardener by the quart and the resin by the gallon. I then put the resin in one quart cans with caps for convenience. If you order the thinner and the resin together you will get hit with a large hazmat charge. The last time I ordered I got the resin and the hardener (thinner lasts forever) and I did not get hit with the hazmat charge. The hardener must be considered non-flammable.

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Randy Muth
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I suspect the Ilva sealer(actually the hardner) contains isocyanates. << ( I think I spelled it right) Use breathing protection when messing with it, even when mixing it.

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I didn't mean to say it, but I meant what I said.
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Woody,

Thank you, it does contain isocyanates and I do use a respirator. Actually, I'm an organic chemist so I'm astute to these types of hazards. To tell you the truth, I'm more afraid of dust (wood, shell, carbon fiber, finish, etc.)

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Randy Muth
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I had no doubt you were using the right equipment. I wanted everyone else to be aware. A good friend of mine has parkinsons. He (and others) believe it's related to exposure to paint fumes. I'm "lucky". I've got allergies and pretty much anything bothers me. I've always used breathing protection. I used to not care what I handled but I've got more aware of skin contact with bad stuff in the last couple years.

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I didn't mean to say it, but I meant what I said.
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What exactly do you mean by "rout it off"? Literally shave it down to nothing by running a spiral bit over it at lower and lower settings?

I have been thinking about this gluing the bridge with CA. One of the reasons I like Titebond is because you have plenty of time for clamping, udjusting, etc. In this case, I am worried about clamping time. I use one of those LMI bridge clamps that autolocates the part. But you still have to apply the glue, spread it around, and tighten the clamp screws. So, do you use a long set CA? And what about squeeze out? I am assuming Titebond on this finish is a no go.

Mike

Mike,

You CANNOT use Titebond to glue to any finish. Titebond is a wood glue. Actually I preferred to use hide when I was gluing bridges in the traditional fashion, since there is no creep.

You rout the bridge off by putting two rails on either side of the bridge and running a router over it. You can take most of the meat off right away and then carefully get very close to the top. The very thin veneer of wood left behinid from the bridge can then be saturated with CA solvent and removed. It's actually pretty quick and is easier than ungluing a bridge, but you do have to make a new bridge.

Here is what I do to glue the bridge directly to the finish. First I sand the bottom of the bridge so that it exactly matches the curvature of the top. This is important and I do this by laying sand paper down on the top and carefully sanding the bottom of the bridge in the area where it will be glued on. It must be a perfect match. I then clean the area with CA solvent and put some thin masking tape on the area of the top where the bridge is going. The cheap beige type. I locate my bridge and scribe the masking tape with a brand new Exacto razor. I peel up the masking tape where the bridge goes and leave the rest (I also locate my bridge pin holes and use small locater holes with brads in the saddle slot). After drilling my bridge pin holes in the top I put masking tape inside the guitar on the bridge plate so no glue seeps through and I lightly scuff up the top where the bridge goes. I put a light coat of thin CA on the bottom of the bridge. This wicks in with no build. I let this cure for a few minutes. I then brush (plastic brush hairs, not natural. A natural hair will cause the CA to react and cure right away) medium viscosity CA glue on the bottom of the bridge and quickly place it into position on the top using my locater holes and brads that are already in the bridge. Hope this makes sense. With one hand inside the guitar and one hand on the bridge I apply pressure for a couple of minutes. I pull back the masking tape and clean up what little squeeze out with CA solvent. That's it.

Here's some of the logic behind it. How fast CA glue cures depends on the pH of the substrate it is in contact with. With woods that are alkaline (high pH), the CA glue cures fast and hot. This is how the accelerator works. With woods that are acidic (low PH), it can take quite awhile. This is the reason why I put a seal coat of thin CA on the bottom of the bridge. Ebony in particular is pretty reactive. For example a mixture of ebony dust and CA will smoke. The KTM-SV must be alkaline because it reacts fast with CA. This is why I don't apply the CA to the finish first, but to the bottom of the bridge. This is also the reason, along with the perfect fit, why you can simply firmly press the bridge to the top to get a good bond. By the time you tried to get a clamp on it, it would be too late and you wouldn't have had the pressure needed during the critical cure time. I have tested this and I cannot get the bridge off without ripping the top apart.

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Randy Muth
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Randy, this is FASCINATING stuff and thank you for sharing!

I am really looking forward to trying the KTM-SV. I will be ordering that plus the sealer material that you mentioned.

Now the question: How long before you string up?

Mike

I usually wait a day, but you probably could safely string-up 3 hours after gluing the bridge. This is what Rick does. Unlike wood glue, I believe CA glue is pretty much done doing what it's going to do after it goes through the exothermic cure phase.

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Randy Muth
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Mike,

A couple of more tips.

When you sand the bridge don't hold down on the wings, since they are flexible. What I do is attach a block of wood to the body of the bridge with double stick tape to use as a handle. This will insure that you have the correct curvature on the bottom of the bridge without forcing it.

When I glue the bridge down, I again use the block of wood as a handle, but also put some pressure on the wings with my thumb and ring finger. I find the brads through the saddle slot are much more accurate and faster than trying to use the bridge pin holes to line things up. Same technique that is used for locating the fingerboard.

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Randy Muth
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Has anyone tried Trans Tint dyes added to Em Tech 6000.The honey amber tint may eliminate the blue hue in darker woods.
James

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James W Bolan
Nashville Tennessee

There was a thread here some time back praising EM6000 so I bought 2 gallons. Haven't tried it yet though. Sounds like it might be best to reserve it for light colored guitars.

What was praise worthy was (and is) the ease of application, the ease of buffing, low toxicity, ease of melting layers, and zero volitiles (will not explode). It is indeed great for light colored wood. On other sites, folks swore up and down it was great for darker woods. According to one poster above, he is able to get good dark wood performance by minimizing finish thickness.