Official Luthiers Forum!

I am getting ready to try KTM9 for the first time.
I am also using the system 3 epoxy filler.
When using the system 3 filler on the top do I need to mask the bridge area? I will of course mask it before applying the KTM9 but I don't know if I need to mask it from the filler to be assured of good glue adhesion.
Any help is appreciated...

Thanks...I will mask it.
The holes for the bridge are drilled.

Yeah, get your entire bridge almost completely set up and mask it a couple mm shy of the edge of the bridge. Thats the way I set mine up with Robbie O'Briens help and it worked perfectly.
-j.

_________________
“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

I too, would recommend not using the epoxy on the top. You would be amazed how much epoxy soaks into softwood. I know that from our use of it on wooden kayaks, where soaking into the wood is a GOOD thing. on those, it soaks completely through the face veneer of the marine plywood and stops at the first glue layer. Seems to me a partially epoxy impregnated soundboard is going to lose something.

I use epoxy on the backs, sides, and neck, and shellac on the top.

Grant

Please mask it!! getting epoxie off from the top will become your worst nightmare!

_________________
Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Bill, other than adding color, why would you want to filler on the top?

Ive used Z-poxy on redwood to darken the color, but there really was nothing to "fill" persay.

_________________
Support the OLF! Bookmark our STEWMAC link Today!
Lance@LuthiersForum.com

[QUOTE=LanceK] Bill, other than adding color, why would you want to filler on the top?

Ive used Z-poxy on redwood to darken the color, but there really was nothing to "fill" persay.
[/QUOTE]

I thought the purpose of using epoxy was to put a hard coating under the KTM to add strength/durability? If you don't need it for it's strength why not just use a waterbased filler on the whole guitar.

_________________
CVT Inc.
A tour of our shop (Somewhat outdated)
My Personal eBay profile. BCWoodBug

For me the biggest advantage to the epoxy fillers is that they don't shrink back as bad creating unsightly pits under the finish.

_________________
Support the OLF! Bookmark our STEWMAC link Today!
Lance@LuthiersForum.com

This is my first attempt with KTM9 so I am trying to follow the directions as closely as I can. The directions state that the epoxy can be used to fill the pores of the top wood as well as the back and sides.
I am trying to go lightly and use just enough to fill the pores and achieve a smooth surface.
After this guitar I may well go back to nitro or I may send the guitars out for finish but I wanted to give this a try.

I have stained or washed spruce tops with Zpoxy for color but fill or hardshell coating is a bad idea in my opinion because of the bridge gluing issues and I would think it would dampen the tops responce as well. I mask the bridge area before washing when I do it. I thin the zpoxy with DA 60% zpoxy/40% DA and pad on. I have not done this in a while, but is not needed. I spray all my KTM9 finishes with two very light shellac seal coat and lightly sand with 400P before applying the KTM9.

The Zpoxy on back and sides is for pore filling only. After filling I sand the Zpoxy back just to the wood then wash them with a zpoxy 60/40 cut as mentioned above to even the color, but not to have a hard film under the finish.MichaelP38796.4073263889

[QUOTE=MichaelP]
The Zpoxy on back and sides is for pore filling only. [/QUOTE]

I'm with you Michael, filling is for open grain woods, spruce is not one of those.

_________________
Joe Beaver
Maker of Sawdust

OK, I'm going to go against the crowd on this one.

I use the KTM-9 / System 3 finish combination and I don't think you need to mask off the bridge area. You do need to remove the finish in the area of the bridge before you glue it on. Tim McKnight posted a real nice tutorial on how to do it this way: bridge attachment

As for the issue of epoxy on the soundboard, my experience is that the system-3 doesn't seem to soak into sitka spruce to any great degree. It does hi-lite the grain a bit which I find to be pretty a nice look. I thin the epoxy half-half with denatured alcohol and wipe it on the soundboard. That seems to be enough to give the visual effect while leaving a thin layer.

As with all finishes, test it out on scrap to see if you like it.

_________________
53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

Never use filler on the top, why would you want to? The filler is there to fill pores in the grain (clue is in the name) the spruce or cedar top should have no open pores, therefore no filler. Just fill back & sides if the wood calls for it, and then rub it back so that just the pores contain filler.

Then, French polish and throw away the KTM9. OK finish with KTM9 if you want.

ColinColin S38796.5204976852

_________________
I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Bill, if your following Mike Doolins direction, he states that you can use epoxy on the top but it is only to provide dent protection but it doesen't provide much and I wouldn't recommend it however. I would just use shellac on the top.

_________________
Tickle your guitar daily, and it'll tickle you back.

[QUOTE=WayneC] OK, I'm going to go against the crowd on this one.

I use the KTM-9 / System 3 finish combination and I don't think you need to mask off the bridge area. You do need to remove the finish in the area of the bridge before you glue it on. Tim McKnight posted a real nice tutorial on how to do it this way: bridge attachment

As for the issue of epoxy on the soundboard, my experience is that the system-3 doesn't seem to soak into sitka spruce to any great degree. It does hi-lite the grain a bit which I find to be pretty a nice look. I thin the epoxy half-half with denatured alcohol and wipe it on the soundboard. That seems to be enough to give the visual effect while leaving a thin layer.

As with all finishes, test it out on scrap to see if you like it.[/QUOTE]

Wayne I don't think you are going aginst the crowd here. But the issue was dealing with an epoxy coat on the top. Depending on viscosity of the epoxy the epoxy may seep much deeper into the spruce than the finish will there by making it hard to get a good glue bond even after scraping back the finish.MichaelP38796.4625115741

I haven't had problems yet with the system-3 epoxy. It seems to come up pretty cleanly when scraped with a razor blade. I might be a hesitant to use it on a more porous wood than sitka, but so far that's the only wood I have used for the soundboard.

_________________
53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/