Katalox — humidity problem or a problematic piece of wood?

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Bryan Bear
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Location: St. Louis, MO

Katalox — humidity problem or a problematic piece of wood?

Post by Bryan Bear »

I have been finishing up two new guitars, one cherry and one katalox. They have been sitng mostly idol lately. The cherry one has been strung for a while waiting for final setup. The katalox (small parlor) has bee unstrung (French polish was finished and beige glued on). The katalox showed what appeared to be a few small cracks in the back. These were barely perceptible and flooding naphtha did not even show through the other side. I hit them with some CA, scraped and resumed French polish.

The RH in the shop got lower than I thought it was in the time I had not need working in the shop. I don’t think it dropped below 30% so not terribly low. Both guitars were braced and glued to the rim at around 40%. The cherry guitar doesn’t show any real issue other than the top shows the corduroy texture a little bit through the very thin French polish. The katalox did not fare so well.

The sides are fine but I can see the other little cracks now and a huge open crack has formed. The strange thing is this crack extends under where the heel block is glued. The surface is not at all flat in the curly areas of the back, you can see and feel the curly texture (obviously this was flat when I started finishing).

It is really hard to photograph but I can get the open crack to show up in the pic.
58DC656E-4C03-42E2-A05F-04D045FA1CC2.jpeg
The sides, that did not come from the same board seem fine. Is this just a bad piece? Will I always have issues with this back?
PMoMC

Take care of your feet and your feet will take care of you.
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Barry Daniels
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Location: The Woodlands, Texas

Re: Katalox — humidity problem or a problematic piece of wood?

Post by Barry Daniels »

It sounds like a problem piece of wood to me. If you were building it for yourself, you could take a wait and see approach. But I would definitely not recommend putting it on the market with that back.
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Bryan Bear
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Re: Katalox — humidity problem or a problematic piece of wood?

Post by Bryan Bear »

The good news is, I am building it for myself. A while ago I finished a little parlor and liked it so much I wanted one. Around that time, I came across this back that I thought was really pretty (and just large enough to get a small guitar from). I thought it was meant to be. . . I guess the good news is I will be keeping an eye on it.

I've never really had a back do this before. It has gone from nice and level/flat surface to telegraphing everything. It looks like one of those 150 year old BRW guitars that have been around for ever and had lots of cracks repaired over its life. Not the look I was going for at all but not necessarily bad.

Do you recomend I get it as hydrated as I can, then fix the cracks and move on? Should I use CA or HHG? I'm not opposed to going back and doing more FP to build up a thicker finish. I could even build it up quite a bit and sand it a bit more level. Or would I be better off leaving well enough alone?
PMoMC

Take care of your feet and your feet will take care of you.
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Barry Daniels
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Location: The Woodlands, Texas

Re: Katalox — humidity problem or a problematic piece of wood?

Post by Barry Daniels »

Hyrdration is good but don't overdo it. Add a bit of moisture and see if the crack closes up.
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Bryan Bear
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Re: Katalox — humidity problem or a problematic piece of wood?

Post by Bryan Bear »

I’m definitely going to take my time and hydrate it slowly. We are in a real cold snap right now. In a week or two it will be much easier to keep the RH in here up. I used royal lac for the FP, by that time it will be pretty resistant to water so if I decide to use HHG, I won’t have to worry about the finish.

I am working really hard to keep the RH up; I’m at 40% now. I have a damp spine in the soundhole too. It is hard to say, but it may have closed up a little already.
PMoMC

Take care of your feet and your feet will take care of you.
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