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KTM-9 on Cocobolo - Finished Build
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10123&t=40397		 Page 1 of 1
Author:  Chameleon [ Fri May 17, 2013 10:18 pm ]
Post subject:  KTM-9 on Cocobolo - Finished Build
I wanted to report on the use of KTM-9 on oily hardwoods. I put it on this cocobolo top without any surface preparation (other than sanding) and so far it seems to work great. I know a lot of people have trouble with oily woods and so far this is by far the easiest way I've found. This isn't a high quality finish job right here but it demonstrates that the stuff sticks.

And here's my newest guitar:

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DSC_0027 by markpotato, on Flickr

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DSC_0030 by markpotato, on Flickr

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DSC_0034 by markpotato, on Flickr

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DSC_0035 by markpotato, on Flickr
Author:  Chameleon [ Fri May 17, 2013 10:20 pm ]
Post subject:  Re: KTM-9 on Cocobolo - Finished Build
This is what the extra switch does:

Switch down:

(5-way):
1. Bridge series
2. Bridge series and middle
3. Middle
4. Middle and neck series
5. Neck series

Switch up:

(5-way):
1. Bridge south coil
2. Bridge south coil with middle and neck south coil
3. Middle and neck south coil
4. Middle and neck in parallel
5. Neck north coil.

No tone pot. the extra sounds make up for it by far.
Author:  Stuart Gort [ Sat May 18, 2013 9:52 am ]
Post subject:  Re: KTM-9 on Cocobolo - Finished Build
Chameleon wrote:
This isn't a high quality finish job right here but it demonstrates that the stuff sticks.


I'm afraid it doesn't...not really. It looks fine but the test that actually proves adhesion is an impact test. Since you aren't going to whack that guitar on purpose you might not ever know how well that finish adheres. Could be it adheres very well. Could be it doesn't.

I have a friend, Lou Fezio...who is the head of the R&D dept. at K2 skis. Lou showed me all their apparatus for testing impacts and helped me quite a bit to develop a process for testing impacts on my composite propellers. I take much of that knowledge into my guitar building. Today, in fact, I'm doing some impact tests on panels that were prepared using a catalyzed polyester system. It may seem like a lot of work...and it certainly is...but it answers questions.

Prior to using any new finishing system on a guitar I test on panels for a myriad of issues...ease of spraying, sanding, polishing, cure times, discoloration...and adhesion. I've sanded far too many whole guitars back down to raw wood to ever want to do it again. :)
Author:  Chameleon [ Sat May 18, 2013 9:42 pm ]
Post subject:  Re: KTM-9 on Cocobolo - Finished Build
If somebody drops it and the entire finish comes off the top, I'll take it back and sand it smooth like I usually do with cocobolo. I'm just not interested enough in mastering all the details of finishing to want to go through all that labor. My wife hates guitars that have a mirror finish because she says it looks fake, like it's made of plastic or something. I see where she's coming from and as a result I don't spend a lot of time on finishes. I think they come out fine the way I do it. I haven't done any impact testing on that cocobolo but it doesn't look like it's going anywhere.
Author:  B. Howard [ Sun May 19, 2013 5:08 pm ]
Post subject:  Re: KTM-9 on Cocobolo - Finished Build
Often times film failures do not develope for quite a period of time. The fact that it has held up through spraying and buffing doesn't really prove much. As the wood moves from changing seasons it will impose stress on the finish and its bond to the wood. Only after several of these cycles will you known if the coating will hold up .
Author:  Mike_P [ Mon May 20, 2013 6:15 pm ]
Post subject:  Re: KTM-9 on Cocobolo - Finished Build
Zlurgh wrote:
Chameleon wrote:
This isn't a high quality finish job right here but it demonstrates that the stuff sticks.


I'm afraid it doesn't...not really. It looks fine but the test that actually proves adhesion is an impact test. Since you aren't going to whack that guitar on purpose you might not ever know how well that finish adheres. Could be it adheres very well. Could be it doesn't.

I have a friend, Lou Fezio...who is the head of the R&D dept. at K2 skis. Lou showed me all their apparatus for testing impacts and helped me quite a bit to develop a process for testing impacts on my composite propellers. I take much of that knowledge into my guitar building. Today, in fact, I'm doing some impact tests on panels that were prepared using a catalyzed polyester system. It may seem like a lot of work...and it certainly is...but it answers questions.

Prior to using any new finishing system on a guitar I test on panels for a myriad of issues...ease of spraying, sanding, polishing, cure times, discoloration...and adhesion. I've sanded far too many whole guitars back down to raw wood to ever want to do it again. :)


words of wisdom that should be followed...I regularly spray a scrap of wood during any finishing process and at the end do an impact test with my hammer (yeah, I know, at the end it is arguably too late but at least you are aware of what's going on)
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