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Mario -
That was my thought exactly when I first started experimenting with
Polyurethane glues. Not reversable. That is always what I heard. But, as
usual, I wanted to find out for myself. So, I took two pieces of wood
roughly 2" x 4". One 1/4" thick (fretboard) and the other a piece of 3/4"
plywood. I glued them together with Elmer's ProBond Polyurethane
adhesive. I let it sit 24 hours to insure that it was cured.
I then attempted to disassemble the glue joint in exactly the same way
that I would remove a fretboard, i.e., I heated the wood with a heat
blanket for exactly 5 minutes. I then used a spatula to try to get in the
joint and separate it. AND IT CAME APART CLEANLY. The surfaces of the
two pieces were actually clean, as if they were never glued together. No
splinters, nothing. So, I conclude that polyurethane glues (certainly
Probond) is most certainly reversable with heat just like Titebond 1, etc. I
no longer view the popular opinion that polyurethanes are irreversable as
good information.
If you have experimented with it and come to another conclusion I would
love to know it!

_________________
Sylvan
http://www.wellsguitars.com

Try the same test but on a week-old, or older, joint. The glue itself isn't fully cured in 24hrs, according to the literature I read about ten years ago when this glue began to appear.....

I've tried to de-laminate my braces(spruce/CF with polyurethane glues, often ProBond), and the wood burned, while the glue held. I've completely burned some brace off-cuts, and all the was left was the CF fibers, and some poly glue residue.

I use regular hardware store epoxy for the fretboard to neck joint; introduces zero moiture, and releases very cleanly.

[QUOTE=Serge Poirier] Having no relief at all on a neck, is that a good thing?

I'm asking because i was told by someone there was none on the neck of my no 2 and that i was supposed to have a bit of relief by another person.
Serge[/QUOTE]

Serge, did that neck buzz when you played it? This Olson did not. He played the puddin' out of it too. Backbow is what you absolutely do not want.... for good reason, it's gonna buzz the frets somewhere.

I have use the LMI white for all but my very first guitar and have had great results. Never had a problem.

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Lance@LuthiersForum.com

Bruce, thanks for the reply, no, i didn't have any buzzes anywhere so i guess that having a very straight neck is ok then? Or should i have an up bow?

Could it be that making a laminated neck prevented having any bows on my guitar's neck?

Back bow is like this Serge, _--_

While relief (the word your looking for aka upbow) is like this -__-

Sorry, there are no curves on the key board the right way.

You only want to turn the truss rod to create back bow (but not realy a back bow) when the neck starts to bow upward from the pull of the strings, causing a dip so to say from the nut to about the 12th fret, after the 12th the fretboard and neck become very thick so any "bow" there is because of poor design and not string pull. This generally doesn't happen for quite some time if you've build yourself a nice stiff neck, but if it does, a little turn of the truss rod should get it "flatter". Some players and builders like as little relief as possible (0.000-0.005") with a feeler gauge, while some like more relief. This is all about setting up the guitar the way you like it. I'm sure your good if you have no buzzing when strumming your momma's guitar.

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Thanks much Rod, i guess that the purple heart is doing a great job so far at keeping that neck straight then.

I really appreciate that!

Thanks again!

Just another 2 cents. I had a couple of partially completed classical
guitars hanging in my shop for 5 years (don't ask why). All the top braces
had been glued with lmii white glue. When I finally got back to them I
discovered most of the braces were about to fall off. Since they were nice
and tight when they were originally glued on, I'm assuming they failed
over time because of repeated humidity and temperature cycles, exactly
what they would encounter as completed instruments touring the world
or being played at home by the weekend enthusiast. I stopped using it.

As far as polyurethane glue is concerned, it works beautifully for back
joints on any oily wood because it sticks to just about anything. When I
bought my Unisaw it came with a Beissmeyer fence. I discovered that a
small piece of formica (or some similar laminate) that was supposed to be
glued to the curved cam that locks the fence in place had come unglued. I
"temporarily" glued it back on with polyurethane. That was over 5 years
ago. If you can clean up the foamy squeeze-out, it's great. Also, don't
forget to just slightly dampen the surfaces to be glued -- it loves
moisture to help it cure. It will take moisture from the air, but cure time
will be significantly longer the drier the air is.
Craig S.

[QUOTE=Dickey] I gave a gallon to another OLFer, cause I knew I'd never use two gallons of White Titebond. Since that luthier never brought it up, I can only think, he decided not to use it for guitars. /QUOTE]


Hey Bruce! That was me you gave the glue to remember? (And many thanks again!! )...I thought I emailed you with a "so far, so good" report but maybe not...just for the record I built 3 guitars with it, keeping the big gallon bottle in the house and the small (LMI ) bottle in the shop...just opened the big bottle to replenish the small, always emptying and washing out the small bottle between refills...I've had no joint failures, opening seams, telegraphing thru laquer, creeping or any other nasties (so far)...I do have some hide glue that I would like to use, but I can't seem to get the speed up for gluing on a bridge with it...I'm using the LMI bridge clamp that uses the E holes and wing nuts....and you'd think Memphis summers would be plenty o' ambient heat! By the by, I'm still only halfway thru that gallon!

_________________
http://www.presnallguitars.com

[QUOTE=L. Presnall] By the by, I'm still only halfway thru that gallon! [/QUOTE]

According to the date, it's time for both of us to toss our gallons, May '05.

I just wanted to try white Titebond for myself, to see if I liked it. Congrats... And from what someone said, the white and yellow come from the same vat, with only added coloring to the yellow. Interesting.

I used Titebond Poly to laminate my last neck. Even with all of my clamps and a lot of attention to keeping it aligned, it still crept. Maybe not as much as another type might have, but as it foamed up, it did creep a bit.
-j.

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-jack handy

Even with all of my clamps and a lot of attention to keeping it aligned, it still crept. Maybe not as much as another type might have, but as it foamed up, it did creep a bit.

When "creep" is mentioned, it is in reference to the cured joint, and not the wet one. All uncured glues will slip and slide to some degree while being clamped. But "creep" is what happens when a cured glue joint moves ever so slightly.

   In reference to the above comments concerning Phil Keaggy's Olson with little to no relief in the neck. Jim's machining ability and the fact that he is an expert in the set up of fine guitars play a large part in the fact that his guitars can be setup with virtually no relief in the neck and offer great dynamic range to the player while not buzzing unacceptably.

   Kevin Ryan accomplishes very much the same thing as he sets his necks up with so little relief that it isn't easy to see without actually fretting the strings at both ends of the register and checking for it.

   In a perfect world, no relief would be best since the saddle and nut heights would provide the clearance for strings that could prove sufficient for minimal buzzing with great action, but things move and change considerably with temperature and humidity in most guitars and it is very difficult to achieve and maintain it. This is precisely why the quality, consistency and rigidity of your truss rod assembly and neck component combinations need to offer a balance between that rigidity and their abilty to function as an adjustable system of parts.

   My typical final spec for neck relief is about .010" at the ninth or tenth fret when the strings are depressed at the first and senevteenth frets. Not perfectly flat, but very flat nonetheless. That's pretty flat, but not completely flat by any means.

    I've played many Olsons and they are usually set a bit straighter than my standard relief, but Ive never measured it for a dimensional reading.

   The straighter the better in most cases where the neck is in good shape and is properly made.

Regards,
Kevin Gallagher/Omega GuitarsKevin Gallagher38944.2521875

[QUOTE=Dickey] [QUOTE=L. Presnall] By the by, I'm still only halfway thru that gallon! [/QUOTE]

According to the date, it's time for both of us to toss our gallons, May '05.

I just wanted to try white Titebond for myself, to see if I liked it. Congrats... And from what someone said, the white and yellow come from the same vat, with only added coloring to the yellow. Interesting.[/QUOTE]

Hi Bruce, yes, I'm gonna have to relegate it to the "household crafts" shelf, and then out...that's interesting that they just add color to it...now, I'm nervous about gluing on my OM bridge...I'd like to get hide glue to work for me...I think I read over on Frets that some are even using CA for bridges?!!    Somehow that just seems wrong, and how would you keep the excess from eating up the finish? (Not that I'd try CA, just curious!!). And thanks again for the glue!!

_________________
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Kevin, thanks so much for your input, that means that a very stiff neck made with laminations of dense wood in the center did do a good job for me then, i will try to repeat that success again!

Thanks

Serge