PU glue

[Michael Thames]

oh yeah and if you haven't tried it yet... plain jane white vinegar does a great job cleaning up polyurethane squeeze out and works swell on epoxy too.

I didn't know that..... thanks for the tip.

[Marcus Dominelli]

BTW, for the life of me, I don't get the logic of the fingerboard being a removable component of the guitar, in my limited career of guitar making I have never once removed a fingerboard and used it again to glue back on. The amount of heat causing warping, and general discombobulation, make the old fingerboard useless, IMHO. I just make a new fingerboard, why would anyone want to use the old warped fingerboard again?

I'm reasonably sure when someone replaced a Torres fingerboard, back in the day, they tossed out the old one and made a new one.

Granted, you've made a lot of guitars, and this is clearly your area of expertise. I started my lutherie career doing repairs and restorative work, so my perspective on glues, finishes, and other aspects of guitar making is probably different from yours.

For example, Removing fingerboards is a pretty common job in a repair shop. Ideally, a good repairman will try to keep as much of the instrument original whenever possible. If the fingerboard is removed properly, it will be in-tact, unwarped, and reusable.

Anyone who has done much repair work will know why epoxy, PU, UF 109, etc, are best to be avoided in guitar construction. Obviously if you're making double tops you have to use a non- water base glue, and there's little choice.
There are places for epoxy, like when laminating sides for example, which I think is just fine, but I would never use it on something that might need to be taken apart for repairs.
Hide glue works great for putting on fingerboards, and for virtually every aspect of the guitar, save for some minor other things. 500 year old hide glue will come apart when needed, and will perfectly bond to fresh, new hide glue.
Tests have shown that Gelatin, and high gram strength hide glue are almost as strong as the best epoxies, and they have proven longevity, something most modern adhesives do not.

When applied to musical instruments, most modern adhesives have a short list of advantages, and a long list of disadvantages, many of which we are not even aware of yet. C.A. glue for example, starts to turn green and break down after 15 or 20 years.
Epoxy shrinks under lacquer, and is degraded rapidy by U.V. light. Who knows what will happen to all those double tops in 20 years? I don't.

As for Torres, I totally disagree with you. He would have saved every scrap of ebony he had in the shop. Ebony was a rare, exotic material that was hard to obtain. One could easily save a lot of money on the purchase of a guitar if a local wood were substituted for the ebony.
Nowadays ebony is absurdly inexpensive, and it makes sense in our wasteful world to just chuck things out and replace them. We live in an age of cheap energy and resources, which won't last forever.

Dominelli Guitars

[Michael Thames]

As for Torres, I totally disagree with you. He would have saved every scrap of ebony he had in the shop. Ebony was a rare, exotic material that was hard to obtain. One could easily save a lot of money on the purchase of a guitar if a local wood were substituted for the ebony.
Nowadays ebony is absurdly inexpensive, and it makes sense in our wasteful world to just chuck things out and replace them. We live in an age of cheap energy and resources, which won't last forever.

Dominelli Guitars

Then why does Romanillios cite Torres guitars that have had the fingerboards repalced?

[Marcus Dominelli]

Then why does Romanillios cite Torres guitars that have had the fingerboards repalced?

Did you read my whole quote? I think you'll find the answer in there. I did'nt say that "fingerboards should never get replaced."

1) Sometimes a replacement cannot be avoided, if for example the board is badly cracked, warped, or worn out.
2) Sometimes the neck on the guitar will pull up from string tension after many years. Rather than shave the bridge saddle down to nothing to make the guitar more playable, a luthier might decide to remove the fingerboard and put on a thicker one, thus improving the neck angle and playability of the guitar.
3) Maybe one of Torres' guitars ended up in the hands of an inexperienced luthier who tried to remove it with heat, burnt it or warped it, and realized that replacing it was now the only option left.

After reading this thread, I think that # 3 is the most likely, but you can choose your favorite story.

[Manuel Liria]

Something I have noticed using HHG is that if you work fast enough to take advantage of the "self clamping properties" of HHG, wood deforms less or nothing. Here is when less clamps can be a good thing in my opinion.


I agree that Titebond creeps. I have a guitar that after a long car trip during summer in Spain increased the relief in more than one millimeter.

(translated from Spanish)

[Michael Thames]

For example, Removing fingerboards is a pretty common job in a repair shop. Ideally, a good repairman will try to keep as much of the instrument original whenever possible. If the fingerboard is removed properly, it will be in-tact, unwarped, and reusable.

I'm curious as to how you remove a fingerboard glued on with Titebond without applying excessive heat? I'd really like to know. I've removed lute bellies HHG by soaking the edge with wet paper towels over night and applying a little heat and they come right off, no problem, but Titebond is a crapy mess. I've never removed a fingerboard with Titebond and wanted to keep it. I know repair shops, do it the quick affordable way, and find re-using the old board to be economically sound, but, as a maker of my own guitars I choose to put on a new board and not risk complications of dicking around with a funky board.

I'm the first to admit I'm not a good repairman by any standard, and I always turn down repair work unless it's my own guitar, and refer people to actual repair people, who admittedly are much better than I am in quick, and affordable repairs.

That said, I certainly can remove a fingerboard and have done it a number of times, I don't think it's rocket science. Since I work only on my guitars, when I remove a fingerboard, the board looks funky to me... can it be re-used, sure but.... at that point I would ask myself, given a choice, would I clean it up and re-use it, or would I just yank a new board off the shelf and use it. I worry about any minuet warping, and shrinking caused by the heat, and I want the repair to be virtually undetectable, that is another reason I plane the existing board down to almost the neck itself and glue on a new one on top....... that way you don't mess up the soft cedro, and have to do any refinishing other than just along the ebony.

If you use any heat you will cause the board to warp, that's a fact of nature, it's unavoidable. I'm how is it Romanillios or anyone can see if a board has been replaced? Yes because it never looks original and is always a bit funky! So I like to avoid that.

To each their own Marcus. That's just how I do it and why I use the glue I use. Everyones standards are different.

When applied to musical instruments, most modern adhesives have a short list of advantages, and a long list of disadvantages, many of which we are not even aware of yet. C.A. glue for example, starts to turn green and break down after 15 or 20 years.
Epoxy shrinks under lacquer, and is degraded rapidy by U.V. light. Who knows what will happen to all those double tops in 20 years? I don't.

Hey, yer preaching to the choir about HHG, totally agree. The only place I use CF is to glue on the heel cap. Concerning epoxy, the only place where UV will affect itf is it you use it as a grain filler otherwise the UV thing is a non issue, light doesn't penetrate through a double top enough to matter.

I used to be rather superstitious about the life of epoxy like you. However, it happens that one of my best friends is a physicist at Sandia National Labs, and he just completed his first guitar in my shop a couple of months ago, he also happens to patent epoxy formulas the lab invents, and is quite knowledgable about epoxy.

So being some what curious I asked him about the life expectancy of epoxy......... he said, think of it in geological terms.

Did you know they inclose nuclear bomb triggers in epoxy? A trigger is a hiroshima bomb. So I'm not too concerned with the life expectancy of epoxy.

[Michael Thames]

Then why does Romanillios cite Torres guitars that have had the fingerboards repalced?

Did you read my whole quote? I think you'll find the answer in there. I did'nt say that "fingerboards should never get replaced."

1) Sometimes a replacement cannot be avoided, if for example the board is badly cracked, warped, or worn out.
2) Sometimes the neck on the guitar will pull up from string tension after many years. Rather than shave the bridge saddle down to nothing to make the guitar more playable, a luthier might decide to remove the fingerboard and put on a thicker one, thus improving the neck angle and playability of the guitar.
3) Maybe one of Torres' guitars ended up in the hands of an inexperienced luthier who tried to remove it with heat, burnt it or warped it, and realized that replacing it was now the only option left.

After reading this thread, I think that # 3 is the most likely, but you can choose your favorite story.

Marcus with all due respect you can theorize about what Torres did, and would have done, all you like, but it's just speculation. I cite examples of early guitars that have non original fingerboards. I've only heard of one case of a bad repair job to a Torres.

[Slavko Fric]

well after all your answer I will not use it..... thanks
that's mean to continue to use epoxy...

hi,
will you glue fingerboard with this?

fric

The question is why do you want to use it for the fingerboard? There's nothing wrong with using Titebond original or hide glue, and either is more pleasant to work with than PU (or epoxy for that matter).

James

just imagine - apply thin layer of glue let say with credit card, spray it light (still have a lot of time for FB alignment and clamping), join and clamp, and after 3-4 hour work with it...
could you do that with any other glue?
while I use Titebond, just to be sure that no wrapping will happened I leave neck clamped 2 day's , to spead process up I switch to epoxy and leave clamped 24h,
and I'm curious what is your clamping time with HHG ,FG and TB.?

Michael how many FB you have to remove ? let me try to gees, from yore 800 you have to replace maybe up to ten.

fric

[Alexandru Marian]

For what my 15 guitars experience is worth, all FBs have been glued with fish glue and I never had any water problems. There is a very minimal backbow only under the first fret or so, which I don't mind as I always leave the wood about 0.5mm thicker than what it needs to be. After I leave it for several days to dry up I plane it to establish the final geometry. A couple light plane passes make it flat.
I clamp it for as long as I have patience, 12h minimum, although it probably gets 100% hard much sooner.

[James Lister]

Fric - I'm not really worried about how long I need the fingerboard to be clamped, I just time my work so that it gets clamped up at the end of the day - and it's ready to work on the next morning. Generally I'd advise against using methods for the sole purpose of saving time. If you have other reasons as well, that's fine.

James

[Slavko Fric]

wrong context of my words , sorry.
main thing is : when I glue with epoxy I don't think about neck anymore, stay flat and stable..
well other will say my neck with TB or HHG stay same but I have had problems and solve it with using epoxy.

I have nothing against you who use TB or others good luck with that .

fric

[James Lister]

wrong context of my words , sorry.
main thing is : when I glue with epoxy I don't think about neck anymore, stay flat and stable..
well other will say my neck with TB or HHG stay same but I have had problems and solve it with using epoxy.
fric

I don't like epoxy because it's unpleasant to work with, harder to clean up than water based glues, and generally not so good for repair work. I don't have any experience with PU glue, but from what others have said, clean up is more of an issue with epoxy, so if that works well for you, perhaps you should stick with it (pun intended).

James

[Michael Thames]

Something I have noticed using HHG is that if you work fast enough to take advantage of the "self clamping properties" of HHG, wood deforms less or nothing. Here is when less clamps can be a good thing in my opinion.


I agree that Titebond creeps. I have a guitar that after a long car trip during summer in Spain increased the relief in more than one millimeter.

(translated from Spanish)

Interesting! A friend here in Santa Fe has an amazing collection of guitars, one is a Rodriguiz that Angel Romero played for years. He has had it here in Santa Fe with no problem for years. Then like you , he made a car trip back to California with the guitar in his car. When he got there he opened the case and found the center top glue joint had separated. He called me later and asked me if I could fix it, I no, and suggested he send it to his good friend Yuris.

I suspect, the joint separated because a glue like Titebond was used. I've seen Titebond kinda swell and the joint get thicker from heat exposure. Titebond gets soft with heat, therefore, for me I don't use it in applications that involve stress.

PU does not separate from heat, HHG, does not separate from heat, and nor does epoxy, the only glue I've seen separate from fairly low level heat is Titebond.

[Michael Thames]

Michael how many FB you have to remove ? let me try to gees, from yore 800 you have to replace maybe up to ten.

Slavko, I've had my fair share of problems with necks over the past 40 years or so. I'm not God, and I didn't invent wood, and humidity fluctuations. However, despite some guys who belittle 800 guitars worth of experience, I feel like this has enabled me to study and see what works and what doesn't..... I learn something new everyday, and sometimes mindless repetition has it's downside.

I've never once replaced a fingerboard on one of my guitars, that I can remember, and believe me I can't remember everything I've done over 40 years. I've had to re plane boards, refret, and in probably 3 or four cases plane down a board and glue a new one on top. In a few cases, during the building process I've screwed up the neck angle and had to remove a board, and simply make a new one and glue it back on.

But I'm not in the habit on removing fingerboards and glueing them back on.

[Marcus Dominelli]

I'm curious as to how you remove a fingerboard glued on with Titebond without applying excessive heat? I'd really like to know. I've removed lute bellies HHG by soaking the edge with wet paper towels over night and applying a little heat and they come right off, no problem, but Titebond is a crapy mess. I've never removed a fingerboard with Titebond and wanted to keep it. I know repair shops, do it the quick affordable way, and find re-using the old board to be economically sound, but, as a maker of my own guitars I choose to put on a new board and not risk complications of dicking around with a funky board.

I'm the first to admit I'm not a good repairman by any standard, and I always turn down repair work unless it's my own guitar, and refer people to actual repair people, who admittedly are much better than I am in quick, and affordable repairs.

You're right about the heat part to remove a fingerboard that's been glued on with titebond, but it should'nt be excessive, meaning too hot, or perhaps too fast. The best way is to use one of those big long heating elements the length of the guitar neck. Leave the frets in, clamp it to the board and plug it in. You want to spend about 45 minutes to an hour heating it up. You'll know it's hot enough by the smell in the room. Titebond gets soft and gummy under heat, so you figure out which way the runout on the neck goes (if there is any) and work a thin palette knife along under the board. If done properly the neck blank will not be warped.

Removing a fingerboard glued on with hide glue is different. Heat alone will not work, since hide glue is, contrary to popular believe, highly heat resistent. It's only when the heat is coupled with moisture that makes hide glue want to fail. So the fingerboard should be wetted such that the board soaks up quite a bit of water. Then the same procedure as I described with the titebond should work.

If you remove any fingerboard too quickly it will probably warp. If you don't even want to use the fingerboard again then by all means take out an old clothing iron, heat up the board, and you can have it off within 10 minutes, but it will probably be cupped and warped.

If it was glued on with epoxy or c.a. glue, it'll need to be planed off or totally scorched.

So being some what curious I asked him about the life expectancy of epoxy......... he said, think of it in geological terms.

I'm not concerned about the life expectancy of epoxy, atleast not for guitar construction, and I'm certainly not superstitious about it. I have two types of epoxy in my shop, West system G-flex, and 5-minute epoxy, which I use it for certain procedures (mentioned in my first post). The longevity of epoxy is a good thing.

My concern is with luthiers who use epoxy for general guitar making - for fingerboards, braces, bridges, general assembly, etc. Guitars made this way are practically unrepairable because the glue is non reversible. That's the concern.