Thermally Modified Dread

[whitespruce]

Thanks Bob, for the kind words AND the questions.

I think, somewhere, there is an explanation of my bracing pattern. I will try to find it and post a link, and add what is missing. In the meantime, I will start with the easiest part of your question....the lightly build UTB.

Actually, the way I construct the neck joint, I could probably dispense with the UTB. First of all, there is no contact of the fingerboard extension with the guitar body...It is totally supported by an extension of the neck, and I actually remove the portion of the top beneath it.





The "A" braces on either side of the soundhole are inset into the neck block so the whole upper end of the guitar is a more or less ridged structure. So there is absolutely no stress on that part of the top that an UTB would need to support. I do use the light UTB just to give a bit of stability to that part of the top, mainly to support the narrow top section between the soundhole and the cut-out, but that is all it does. I have been doing this since 2002 and it has worked fine.

Answers to the rest of your question will follow.

G

[RusRob]

Thanks for that explanation Grant. That is a very interesting solution to the problem of the torque placed on the top by the fretboard extension. I am guessing it also eliminates the issue of the 14th fret hump (assuming you don't glue the FB extension anywhere).

I have seen in some of your other build threads where you had that cutout section of the top but didn't really want to sound stupid by asking about it but it is a pretty creative way of doing it.

It also appears from your mock up that you inset the heel right up to the heel block so the heel does not even sit on the sides. That seems to be another interesting idea that eliminates the need to floss the neck and makes a nice clean tight looking joint.

Nice... Very Nice.

Cheers,
Bob

[whitespruce]

Bob, here is a more complete explanation of my neck joint

http://luthiercom.org/phpBB3/viewtopic. ... 160#p52160

G

[whitespruce]

Well, this has been sitting for while, so time to update.

I had earlier tried to bend thermally modified sides and they all broke. Well after looking at other folk's bending woes and doing some thinking (mostly getting over my stubbornness), I decided to do some experimenting. I had a set of thermally modified Beng sides so...

When my Son was visiting last week, I sent him to town to pick up some Downy fabric softener. I thicknessed and cut to profile the TM sides. Then I painted them with the Downy, thinned with a small amount of water, wrapped in plastic wrap and set aside. With all of the commotion around here, they sat for 3 or 4 days. So today, I got them out along with my bending stuff. They felt kinda waxy, so I scrapped off the excess fabric softener and sprayed them well with water. Then wrapped in my usual paper and foil and proceeded to bend. Since they were already thermally treated, I cranked up the temp to 350. I had thinned them to about .070". I did the bending slowly and heard no cracks. Let them cool and gave them another 10 minutes of heat. Came out perfect!! So did the other side.



Now, mind you, this is not a cutaway or other sharp bend, just a dread, but it seemed to bend very easily. Now, I need to do some more experimenting, now that I have overcome my fear.

As you can see in the above photo, I have the laminated linings made. I also have the neck mostly ready and the end blocks made



So now, I can get on with finishing this build.

If I can get reliable results with the fabric softener. I will send some other side billets to John and we can get on with building more thermally modified guitars...

G

[Pat Foster]

Grant,

That's coming along great! I still marvel at your bracing pattern. I'd love to do some Chladni voodoo on one of your tops, just out of curiosity, see what kind of "fingerprint" they have.

Pat

[whitespruce]

Grant,

That's coming along great! I still marvel at your bracing pattern. I'd love to do some Chladni voodoo on one of your tops, just out of curiosity, see what kind of "fingerprint" they have.

Pat

Pat, Dave Livermore tried that at Stringfest a couple of years ago. Did not form any pattern...just seemed to keep moving everywhere. There seemed to be a hint of concentric "rings" of jumping glitter, but nothing stopped moving anywhere. He finally just gave up. Wish I had taken photos.

G

[Pat Foster]

Interesting. I've never seen that. 'Course I've never seen a bracing pattern like yours either, and that's a good thing.

I wonder if he was feeding too much power. Dunno.

Pat

[whitespruce]

Pat, I have nothing to suggest. As you know, I don't even try to fathom the left-brain stuff, though I respect those who do. Guess I see the different approaches as simply different roads that eventually get us all into town...some just read a different map

All I know is that everybody who plays one of my guitars seems to love the sound, and that is good enough for me

But all the talk of "resonate frequencies", "main air", the graphs and charts, etc., etc. might as well be in Swahili or something so far as my brain is concerned I look on what I do as art, not science, and go by what my hands feel and my ears hear. Yes, and some things I don't even measure (except fret spacing) or at least only to the point that it gets "close enough". I don't even worry about things like neck angles (though I see some folks going anal about it). The way I build, it just "happens" and it always seems to work. If somebody were to ask me about, I would honestly have to admit that I do not know.

Guess you need to come to Stringfest.

G