Martin non-adjustable truss rod

Old duck

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This may not be the best place to post this, but I don't want to join a Martin/acoustic forum for one question. Hopefully someone here has an answer. I'm pretty much a solid body electric guy, but I recently acquired a 1978 Martin D-35 as part of a trade. The poor thing looked like it was played in a bar every night since new and occasionally used in a fight, as a club. Anyway, after cleaning all the cigarette smoke and sweat and spilled beer off of it, it looked good enough that I decided to get it playing. There are about a half dozen side body cracks and pick guard splits and places that need repair and it needs a refret and a fingerboard plane, but the real issue is the neck. The fretboard extension and the rest of the neck were in two different planes. It appears someone did a neck reset and didn't shim the neck high enough, so the fingerboard has to slope up to the body level. The neck itself has about 3/8" relief with the strings tensioned and .050 relief with no strings. After looking at it for a couple days I decided to pull the fingerboard and put in an adjustable truss rod. and then see if it needs another neck reset. (I know, Martin purists will scream) The fingerboard came off as expected and I found the 3/8 square steel tube fixed truss trod as expected. I tried heating the tube to remove it and can't get it to budge. Part of the problem is that it is 14" long and it is hard to get the whole thing hot at once, without over heating the neck. Does anyone know of a trick to get this sucker out?
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dan1952

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Those nonadjustable truss rods work very well, but the problem is your neck set. The adjustable truss rod doesn't have any effect on that. Leave the truss rod alone and find a pro to undo the bad reset and do the job right. Please don't keep performing amateur repairs on a great old guitar.
 

stormin1155

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I'm with Dan... to get that rod out could require force and/or heat that could do some serious damage. I've worked on lots of pre '85 martins with those rods, and they do a good job keeping the neck straight. If the overall neck angle is good, it's pretty easy to put a shim under the extension. If not, now is a good time to do the reset.
 

Old duck

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Those nonadjustable truss rods work very well, but the problem is your neck set. The adjustable truss rod doesn't have any effect on that. Leave the truss rod alone and find a pro to undo the bad reset and do the job right. Please don't keep performing amateur repairs on a great old guitar.
Thanks, but this guitar is far from a "great old guitar." It is unfortunately, a POS. Though I generally don't work much on acoustics, I'm not an amateur. If you could see the neck, you would see that a neck reset won't solve the problem. It has an 'S' bend in it that a reset can't possibly fix. Anyway, I only have a couple hundred dollars in it, so I don't have much to lose.
 

dan1952

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Thanks, but this guitar is far from a "great old guitar." It is unfortunately, a POS. Though I generally don't work much on acoustics, I'm not an amateur. If you could see the neck, you would see that a neck reset won't solve the problem. It has an 'S' bend in it that a reset can't possibly fix. Anyway, I only have a couple hundred dollars in it, so I don't have much to lose.
Okay, then! I take back the "great old guitar" and "amateur " remarks. Sounds like your diagnosis or terminal POStivity is correct, sir, and I concur that the surgery should continue as scheduled. You may fire when ready, Gridley!
 

Old duck

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Okay, then! I take back the "great old guitar" and "amateur " remarks. Sounds like your diagnosis or terminal POStivity is correct, sir, and I concur that the surgery should continue as scheduled. You may fire when ready, Gridley!
Update, I heated the tube with a pencil torch and pulled it out and it worked ok. By the time I put in an adjustable rod and sand the gouges out of the fretboard and refret it, I'll have about $450 in it so I can sell it for $500 and make tens of dollars of profit!!! :)
 

Freeman Keller

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Lets see, the Martin tube truss rod is 3/8 by 3/8, a single acting rod is typically 0.470 by 0.400, a SM hot rod is 7/32 by 7/16 deep, LMII's rods are 1/4 by 3/8. You'll need to drill a hole thru the neck block and the UTB (or out the head) for access. I don't know of any adjustable truss rod that will remove 3/8 inch of relief. Plane the neck flat and reinstall the f/b eliminating any humps at the body joint and maintaining the correct geometry since you don't seem interested in resetting it. Refret it, replace the pick guard (fix the p/g crack if it has one), fix anything else that doesn't show in the pictured.

Its too bad because Martins with the tube truss rods tend to have pretty stable necks - both my 60 year old guitars have about 10 thou relief, have been reset and refretted and are worth a bunch of money...
 

Old duck

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Lets see, the Martin tube truss rod is 3/8 by 3/8, a single acting rod is typically 0.470 by 0.400, a SM hot rod is 7/32 by 7/16 deep, LMII's rods are 1/4 by 3/8. You'll need to drill a hole thru the neck block and the UTB (or out the head) for access. I don't know of any adjustable truss rod that will remove 3/8 inch of relief. Plane the neck flat and reinstall the f/b eliminating any humps at the body joint and maintaining the correct geometry since you don't seem interested in resetting it. Refret it, replace the pick guard (fix the p/g crack if it has one), fix anything else that doesn't show in the pictured.

Its too bad because Martins with the tube truss rods tend to have pretty stable necks - both my 60 year old guitars have about 10 thou relief, have been reset and refretted and are worth a bunch of money...
I think this guy sat in a shed for a few years with high heat in the summer and cold/damp in the winter. It has been very mistreated. I've repaired a bunch of side body cracks and filled/repaired the p/g crack. I done about 50 guitars in the past two years and many, many over the past 60 years and I've never seen a neck like this. I don't even understand how it could happen since the square tube truss rod was very securely glued in the neck. Anyway, I'll get it done in a week or so. I've had 4 or 5 70s Martins that didn't have any problems.
 

dan1952

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Update, I heated the tube with a pencil torch and pulled it out and it worked ok. By the time I put in an adjustable rod and sand the gouges out of the fretboard and refret it, I'll have about $450 in it so I can sell it for $500 and make tens of dollars of profit!!! :)
Beautiful, baby!
 

TwangerWannabe

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Neck relief and the angle of the neck set are two different things. As others have mentioned, adding an adjustable truss rod isn't going to fix an incorrect neck angle, it will most likely just create more problems for a guitar that already seems to have too many issues to begin with, so no need to go and crate more unnecessarily.

If that thing was mine I'd pack it up and ship it to Bryan Kimsey and get his assessment of the guitar and if it would be worth it or not to restore and possibly hot rod into something better than what it was when it was new, since the 70's Martins were notorious for being overbuilt and a bit stiff and stifled sounding. Depending on how much you have into the guitar already it may be worth it to get the neck angle corrected and set properly, address the frets (regret if necessary), have a new pickguard made, check that this one doesn't have the ever-so-common intonation issue (but that's easily fixed by Bryan since he has most likely done that fix with scooting the bridge more times than you can imagine) and then replace the giant rosewood bridsgeplate with a smaller one and scallop the braces to really bring that guitar to life. Cleating cracks and glueing loose braces is pretty easy and a common repair.

I'd say if you're going to put in the effort to get this thing back to playable condition, you should have a real pro evaluate it and see if it's worth it and have it done right. Not knocking your ability, just seems like an old Martin at least deserves it.
 

Freeman Keller

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Bryan has worked on both of my Martins and I just talked a friend into sending his D35 down there. Basically I had all the things Twanger describes done to my 74 D-18, it is a far better guitar as a result.

I will add that both of my guitars, a 74 D18 and an 80 D12-28 have non adjustable truss rods - the 6 string has 10 thou of relief and the 12 string has a bit more but still tolerable. I'd like a hair less but when you stop and think that 40 year old guitars are that neck stable you wonder what is wrong with the new ones. Both guitars have had resets, the action is sweet and low and I've been offered a pretty nice price for the six string but I'm not interested in selling it.
 

TwangerWannabe

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Bryan has worked on both of my Martins and I just talked a friend into sending his D35 down there. Basically I had all the things Twanger describes done to my 74 D-18, it is a far better guitar as a result.

I will add that both of my guitars, a 74 D18 and an 80 D12-28 have non adjustable truss rods - the 6 string has 10 thou of relief and the 12 string has a bit more but still tolerable. I'd like a hair less but when you stop and think that 40 year old guitars are that neck stable you wonder what is wrong with the new ones. Both guitars have had resets, the action is sweet and low and I've been offered a pretty nice price for the six string but I'm not interested in selling it.

Despite a non-adjustable truss rod, your older guitars also most likely have a beefier, thicker/more substantial neck, compared to the MLO profile necks (or thinner) many of the newer Martins have. Some even argue that those older guitars used old-growth wood and the wood was also possibly seasoned longer/left to dry out longer than what is used currently, and all those factors possibly result in a much more stable piece of wood.

My '75 D-28 that also had a non-adjustable truss rod and had a bit of relief in it but the shopped a compression refret and it had just a hair of relief and played like a dream. The shop said over time it would get a tiny bit more relief and the neck settles with the new frets, but should not change much at all.

Look at an new Martin Authentic model. These don't use adjustable truss rods either, but the one thing those models have are pretty darn chunky necks. Even though the 70's models necks aren't as chunky/substantial as the Authentic models, they're noticeably chunkier than current Martin necks.
 

Old duck

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Update: This kind of turned out to be the project from hell. The body took way more hours than I thought it would due to six body side cracks (one was 5" long) and five dents in the top (one was 10" long) that looked like someone had pressed a low E string into the wood. I used CA on the cracks and lacquer to fill the top dents. Came out ok, but probably took about 6 or 7 hours and way too much sandpaper. Anyway, the truss rod went in okay and I drilled the neck block. Whether it will hold the neck sufficiently against string tension remains to be seen. I sanded the fingerboard from the 20" radius to a 16" radius to get rid of the fingernail gouges between the D-G-B-E strings and got it glued back on. The neck is now perfectly straight with the body. Just need to get new frets on it and I can get it out of my shop.
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Old duck

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Any pictures of the top and rest of the guitar? Good luck with the neck. Seems like an awful lot of work.
Well, sort of. It's hard to get cracks and repairs to show up, but I took these.
This shows some of the the "dents" in the
top after repair. There are three there, two dark ones and one light colored. They have been filled with lacquer and sanded/polished. Hopefully they look kind of like natural grain variation. There are more on the other side of the body.
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Across the light they look like original finish.
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This is one of the areas where the side was pushed in between the two obvious repaired places. I pushed the sunk in place out from the inside and used CA to repair the cracks. The finish on the side is very thin and I ended up having to sand through a larger area to level the pieces. I airbrushed new lacquer of this area and am letting it cure for a while before I rub it out.
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