Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

[GuitarDoc]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Tape or string should hold it in place as well, don't you think

No.
But you could clamp boards on either side of the neck to keep the fretboard aligned..as long as they don't get in the way of the backing board and clamps used to clamp the fretboard to the neck.

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

I use a boatload of these...
https://cdn.cremonatools.it/media/c...f78eab33525d08d6e5fb8d27136e95/5/0/504913.jpg

But you probably don't have any right now. The problem with boards along the sides is the neck is tapered, and most clamps don't like that. And boards do get in the way most of the time.

Not a bad idea on the pin - it's a common build method. What I've done for decades is use the minimum amount of glue so the part doesn't slide around, and remember there is a certain amount of working time before the glue starts to set. Take your time before you bear down with the clamps (and use cauls to protect the wood). Got any nylon strapping clamps? They can align the board before tightening your clamps down. Or do like the builders do - make a jig. (but it's a lot of work, and you'll only use it once)

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Hmm. I was planning on using a fair amount of glue, then clamping a big flat board over the fretboard to evenly distribute the pressure. I can see how that will make life difficult with aligning the fretboard perfectly. I do have some nylon straps. Maybe they can be used to hold everything in place properly while clamping. This will require some thought on my part.

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

This will require some thought on my part.

A solid plan for life as well as guitar repair.

 

[GuitarDoc]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

The problem with boards along the sides is the neck is tapered, and most clamps don't like that. And boards do get in the way most of the time.

Absolutely correct. That's why I gave that as my last option for handling the issue.

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Regular general purpose Titebond wood glue should be fine for the gluing, right? I've got that and some Gorilla brand wood glue.

As far as holding the board in place . . . I'm thinking secure it with some zip ties, clamp it, then remove the zip ties. Does that sound sensible?

Also, this youtube video (https://www.youtube.com/watch?v=TTUVB_6NK5A) suggests sprinkling a little table salt to prevent the fretboard/neck from sliding away from each other. Makes sense to me. Does that sound safe to everyone?

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Regular general purpose Titebond wood glue should be fine for the gluing, right?

Yes.

Gorilla glue.

DEAR GOD, NO!

I'm thinking secure it with some zip ties, clamp it, then remove the zip ties

Sounds like a plan.

suggests sprinkling a little table salt to prevent the fretboard/neck from sliding away from each other

Actually, just a grain or two will do it. A builder I know uses a half dozen tiny grains of very fine sand, because it's chemically inert, and dents the wood during clamping.

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Another question for the pros - this one about truss rod installation.



I'm installing one of these U-channel/Martin style truss rods:

There's like a metal box with one side missing that covers the rod. The open side of the box goes down into the channel.



Stew-Mac says you should epoxy the truss rod in: https://www.stewmac.com/How-To/Online_Resources/Learn_About_Truss_Rod_Installation_and_Repair/Truss_Rod_Installation.html

My concern is that this will make it really easy to get epoxy at the open end where the truss rod is . . . which would probably cause the truss rod to freeze in place immediately after installation. Is this step really necessary? As far as I can tell, the truss rod that was already in there was not epoxied in. The channel is a pretty tight fit around the metal box on the sides so I'm not sure how much epoxy would actually get in there anyway.

Is there anything I need to do with the truss rod to avoid rattles?

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Yes.



DEAR GOD, NO!



Sounds like a plan.


Actually, just a grain or two will do it. A builder I know uses a half dozen tiny grains of very fine sand, because it's chemically inert, and dents the wood during clamping.

Thanks BTW, I really appreciate the advice.

 

[GuitarDoc]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Yes.



DEAR GOD, NO!



Sounds like a plan.


Actually, just a grain or two will do it. A builder I know uses a half dozen tiny grains of very fine sand, because it's chemically inert, and dents the wood during clamping.

I don't think I would consider the salt, but the sand idea sounds logical.

 

[nexion218]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

DEAR GOD, NO!

Just curious... What makes the apegoo that big of a "NO"?

 

[GuitarDoc]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Is there masking tape on the bottom of the truss rod? Leave that in place, it keeps the epoxy from getting into where the actual rod is. The epoxy keeps the truss rod secure so it won't rattle and so it will function properly. You don't need much epoxy, just enough to hold it. Make sure you don't get any on the adjusting threads.

Sounds like you're on your way. Great learning experience.

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Is there anything I need to do with the truss rod to avoid rattles?

The chances of that happening is very low, but epoxy would reduce the risk. However - any repairman who had to deal with such an installation would be perfectly within his rights to hunt you down and kill you. ALWAYS consider how your build techniques will affect any future repairs. There is a LONG thread on this very subject over on the Official Luthiers Forum.

 

[ehdwuld]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Well this will probably be the last repair before the guitar meets a fence post

Just saying

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Is there masking tape on the bottom of the truss rod? Leave that in place, it keeps the epoxy from getting into where the actual rod is. The epoxy keeps the truss rod secure so it won't rattle and so it will function properly. You don't need much epoxy, just enough to hold it. Make sure you don't get any on the adjusting threads.

Sounds like you're on your way. Great learning experience.

I'm waiting on the truss rod in the mail, should be here Wednesday or Thursday. It sounds like there will be masking tape on the bottom of the truss rod. I pulled out the old U channel/truss rod to look at it last night, and it was tricky to get back in because the sides fit so snugly. I'm worried that if I epoxy the sides of the channel when I push the truss rod in it will push all the epoxy to the bottom and cause problems. (Also kinda worried about damaging the masking tape and wrecking the rod as it gets jammed in there). Should I put the epoxy on the sides of the truss rod to avoid this happening.

Would the epoxy on the U channel make the neck more solid/stable? There must be a reason the Stew Mac instructions say to do it.

Also, does it matter what epoxy I use for this? I think the stuff I've got in our basement is probably bad (about 10 or 15 years old now) so I'll have to get some more. Might as well get the right stuff.

The chances of that happening is very low, but epoxy would reduce the risk. However - any repairman who had to deal with such an installation would be perfectly within his rights to hunt you down and kill you. ALWAYS consider how your build techniques will affect any future repairs. There is a LONG thread on this very subject over on the Official Luthiers Forum.

So, the Stew Mac instructions are not good?

Run a thin line of epoxy down both sides of the bottom of the slot and install the truss rod with the rounded side (with the masking tape) down. The flat surface of the rod should be facing upward, almost flush with the top of the neck.

Do not remove the masking tape that is on the rod. It prevents the glue from getting into the mechanism, which could cause adjustment problems. Clamp the rod into the slot and promptly remove any glue squeeze-out. Leave your clamps in place until the epoxy has properly cured.

Like I said, it's a pretty tight fit in the channel. I think that only a very tiny amount of epoxy would manage to get between the wood and the aluminum U-channel, not sure if this would be a problem for someone (let's be honest here - me) in the future doing a repair.

Well this will probably be the last repair before the guitar meets a fence post

Just saying

Yeah, there's also that.

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

I think StewMac and Dan Erlewine should know better than to use epoxy for this repair. The problem is once the wood has been contaminated by epoxy, it's over. You can't get the crap out of there so that it can be glued in properly. You can soften the epoxy with heat, and remove the truss rod.... But there would be no point.

Just because it's not worth the money to do a proper and complete repair, doesn't mean someone COULD fix it right in the future. Like if you donated the guitar to a program that fixes guitars to be given to underprivileged kids? Get it? We don't know the future of anything.... even a cheap POS guitar. I've saved a lot of stuff that didn't deserve it, either to learn or to give away.

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

I think StewMac and Dan Erlewine should know better than to use epoxy for this repair. The problem is once the wood has been contaminated by epoxy, it's over. You can't get the crap out of there so that it can be glued in properly. You can soften the epoxy with heat, and remove the truss rod.... But there would be no point.

I'm confused. Why couldn't you just run a file (or some sandpaper) over the epoxy in the channel to remove it? (Assuming that you need to pull the new truss rod out again for some reason in the future.) As mentioned, it's a tight fit . . . there would only be a very small amount of epoxy between the U channel and the wood anyway, just enough to fill any small gaps that exist and hold the rod securely in place.

Just because it's not worth the money to do a proper and complete repair, doesn't mean someone COULD fix it right in the future. Like if you donated the guitar to a program that fixes guitars to be given to underprivileged kids? Get it? We don't know the future of anything.... even a cheap POS guitar. I've saved a lot of stuff that didn't deserve it, either to learn or to give away.

I am doing a proper and complete repair. At least to the best of my knowledge and ability. My intent is to fix it right this time, that's why I've been asking questions. I appreciate the input from everyone. I'm just perplexed that the instructions that come with the truss rod that Stew-Mac has been selling for decades would be so wrong as to cause the instrument to be irreparable in the future. Dan Erlewine has been the source of an awful lot of really good guitar related information over the years. I'm kinda hesitant to ignore their advice out of hand.





Speaking of questions, one more for everyone . . . the current truss rod sits about a mm (or maybe half a millimeter) below the top of the channel that is routed in the neck. I don't like any gap being there in the neck. My inclination is to fill it with wood filler before gluing the fretboard down so that there's a completely flat surface to glue to, and no room for the truss rod to slop around before applying force on the neck during adjustment. Is this a good idea? Is wood filler suitable for this, or should something else be used? (If it was deeper I'd cut a strip of wood or something, but think it's too shallow to be able to do that properly.)

My tracking number says that the order is in my mailbox right now, so I'll get to do a test fit tonight. Exciting!

 

[ICTGoober]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Why couldn't you just run a file (or some sandpaper) over the epoxy?

Because the epoxy contaminates the wood. It gets down in the grain, and prevents any future glue from getting a grip.

My comment about the future wasn't directed at you per se. But weren't you told fixing it wasn't worth it? It might be true, but it doesn't make the guitar worthless, that's all I'm saying. It's not trash to be thrown away or burned in a campfire.... I digress, didn't mean to confuse you. I'm glad you are making the effort to restore it to usefulness.

 

[GuitarStv]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Because the epoxy contaminates the wood. It gets down in the grain, and prevents any future glue from getting a grip.

Would using titebond on the sides instead of epoxy be a better idea then? I feel like there must be a reason that the recommendation to glue the rod in is there. Does it better distribute the force of the rod?

 

[GuitarDoc]

Re: Extreme acoustic guitar surgery - watch me destroy a beloved instrument!

Actually, Titebond is not a good idea because it shrinks as it dries/sets. The epoxy is a better idea. Follow Dan's advice...he really DOES know what he's doing. Probably more than anybody on this forum.

The shrinkage of Titebond makes it a great product for gluing the fretboard to the neck...it actually tightens the connection as it sets.

Besides, you're not worried about the epoxy sticking, or any other "glues" of future repair jobs sticking. That is NOT the purpose of the epoxy or whatever you decide to use anyway. The purpose of the epoxy is as a filler...to fill in all the tiny gaps and to hold the rod secure, to keep it from any movement or flex when it is tightened in the future. For your neck and truss rod to function properly, all components of the neck have to be intimate/as one piece. Epoxy keeps the rod secure and free from any motion or rattle. Glue keeps the fretboard secure to the neck.Each material used in guitar making or repair has its unique application/purpose.