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I shot my first couple coats of KTM-9 today, I've run into a couple of issues here and there...

The three guitars I'm shooting all where epoxied and sanded smooth, I hit them all with a final of 320 a couple of weeks ago, wiped them all down started working on them today..

1. The first thing I noticed was that on the first coat I got a pretty uneven application, after letting that set for a while I sanded it flat and shot again and it looks much better on the second coat. The Koa has taken the best coats and I'll apply a third tonight and see what happens.

2. It doesn't seem to burn in like McFaddens does, I can see fine sanding scratches from coat to coat. so should I be shooting with DA between coats if I sand?? that seems like alot of extra work to me, even with a span of say 4 hours it still doesn't seem to burn as nice as a standard lacquer.

3. With the epoxy all my rosettes where flat, but after the first couple of coats you can now see various rings in the rosettes as ridges when you look in a raked light. I'm going to let it cure out for about 6 hours and see if I can level those areas with some 400..

4. I can now see the center seam in the raked light, it's a little disconcerting because this simply doesn't happen with McFaddens. It's not a bump but more of a little idented line, my thinking is because it's water based it swelled the wood a little and I'll try leveling with with some 400 before moving on.

This is like starting all over in finishing, I got so conditioned to McFaddens and it's properties. KTM runs easier and it's a bit tricky to get a good gloss coat without them, after tweaking my HVLP I got a proper fan that seems to work well with the finish. But I'm concerned that it's going to be a ton of work to get a good solid finish on my instruments, I may go back to McFaddens for the next one to compare after I figure this out.

It seemed to do fine on the necks, I was pretty happy with the way it applied there, lots more coats to go but even these initial coats look pretty good.

I do like the water cleanup and I don't see ANY clouding so far or blue tint, in fact on the Koa the wood just jumps. Any advice would be greatly appreciated, I'm in new territory here...

Thanks

-Paul-Sprockett38374.8436111111

_________________
-Paul-

Patriot Guitars

Paul, just a couple of things that come to mind. For some crazy
reason, KTM-9 doesn't like tightbond. It will sink in on top of it
and you'll have a hard time getting it level (that might be your
center seam issue). Also, how much of the epoxy are you
sanding off. I've read,and practice too, that you never go down
to bare wood. That will prevent all sorts of problems, one being
that the waterborn won't swell the wood as you speak of
because it never hits the wood.
Not sure about your scratches. I always hit mine with a coat of
DA real quick and have 100% burn in when I do that. I've read
that it's necessary to get burn in but I haven't tried it without DA
so I'm not sure. It's really not too big of a deal. You really don't
even have to let it dry, just a light mist coat and by the time you
have the gun loaded with KTM it's ready for it.
Hope that helps a bit. Paul

Thanks for the feedback Paul..

I use Hide Glue on all my seams, I sanded down to a thin coat of epoxy and on the final actually applied it with a rag to get a super thin coat on. It's very strange how it reacts on that seam, however I *think* it's because my coats are too thick and it's creating a fish-eye over that seam. I'm going to try drying them out a bit and see how that works, I'll try some DA for tomorrows run and see how it works, I have a little trim gun that I can use for that.

Switching to 400 seemed to help a bit with the sanding marks (it's the way I did McFaddens), I'm wondering if you can mix a little DA right into the KTM, I'll drop them a note and see what they say about that.

I really like that this stuff is non-toxic and if the Koa is any indicator this stuff should be wonderful when I get my steps corrected.

Thanks

-Paul-

_________________
-Paul-

Patriot Guitars

I was just digging and on the LMI site Grevan suggests using a little DA in the mix to help distribution (it's gotta help with burn in too) so I'm going to try his steps tomorrow, it's pretty close to how I did McFaddens (in case you can't tell I still consider it the gold standard )

If Grevan and Doolin can make it work then I'm just being a goof and not doing it right

-Paul-

_________________
-Paul-

Patriot Guitars

Well it's been a long weekend, I've learned alot about spraying KTM-9... At one point I was considering going back to McFaddens but I persevered and think I have this figured out.

There are a couple of tricks that I learned, Doolin and Grevan both suggest using DA in the process, I tried Mikes way and Johns way and what I found was that if you up your ratio of DA INTO the cup and spray on a gloss coat it will burn in correctly, the trick was about a 4:1 ratio for the DA (4 parts KTM and 1 part DA) sounds like a lot but Doolin sprays the guitar directly with DA between steps so I don't see a big difference, plus it flowed better and I was able to get a thinner gloss coat this way.

The downside is you have to be very careful of runs, I have all three in the closet drying now and ordered another quart of KTM so I could finish the necks (I been tinkering mostly with the bodys).

I'll post some pics once I get these leveled and polished a couple of weeks.

Cheers

-Paul-

_________________
-Paul-

Patriot Guitars

Paul,
here is a trick for the center seam, the whole guitar actually. Pad or spray on a 2lb cut of shellac as a seal coat. I like to pad then stiff with a little DA. This puts a very adhesive layer between the titebond and the KTM-9. In fact I would recommend this as a seal coat on any coating system

Thanks for the info. guys. I have tried Target USL, and it did not work out well for me. But I don't want to give up yet, and some of your tips and ideas could be the answer.

Jeff