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Hi all,

I have a 70's Martin in the shop whose top has cracked along both sides of the FB extension which as a result has slid towards the bridge and made the guitar unplayable. I am thinking I will need to remove the UTB and the popsicle brace, repair the cracks, then reglue the braces. Is that the best technique to repair it? What's the best way to go about removing those two braces? If there's a walkthrough posted somewhere it would be much appreciated.

On a related note, was Martin using white glue in the 70s?

Hot pallet knife and a bit of moisture to remove the UTB and popsicle brace. Clamp the guitar body down to the bench and with a quick or f-clamp bring the peghead down (that should rotate the neck block) until the correct geometry is recovered: the rosette lines should align and the neck set should be correct again. Then glue back the UTB and popsicle brace, I would also glue spruce reinforcement between the UTB and soundhole, and on each side on the neck block under the top cracks.

Martin used white and/or yellow glue for pretty much everything except gluing the plates to the rim (HHG).

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

this very repair is covered at FRETS.COM . You most likely have a top that was loosened from a previous neck set .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I have repaired several guitars with this problem and they seemed to have occurred due to overheating in a car. It is not really necessary to remove the UTB and that would be very difficult to do without taking off the back. Clamp the guitar down as Laurant already described and use a little heat in the headblock area if necessary, until everything lines up. Then reglue the UTB. It is often helpful to add a couple of braces on the sides of the headblock up against the top (also described by Laurant). These will back up the cracks and lock everything into place much better than the reglued UTB.

Thanks for the replies. I'm hoping it will hold OK without removing the UTB... it's tucked into the linings on both sides and I'm not sure I could remove it without some collateral damage.

Instead of clamping down the butt and peghead to my bench I'm using a turnbuckle inside the box that pushes against the heel block and the tail block to get the neck angle just right. Same difference I guess, it just feels like a better option for me.

Be sure to place a clamp from the tail block to the base of the head block on the outside of the body to prevent
the tail block from blowing out when you crank the turnbuckle.

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Keith MacKenzie
Location: Florida
"To err is human to really screw up you need tools"

I have used this technique many times with fantastic results. The use of a turnbuckle may work just as good but could limit your clamping ability with the guitar in traction.

http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Structural/Cracks/D45FBTopCrack/d45fbtopcrack.html

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- Louis Freilicher

Oh No! Not another learning experience!

If things have deformed over time, even after rotating the neck block back into position, there can still be a dip above the soundhole. That's a good reason for removing the UTB and replacing it with one that brings the top back up. As Frank shows, at that stage, they come out pretty easily. Getting them back under the lining is a pain but is doable. You can also remove and replace the lining blocks over the brace.

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http://www.chassonguitars.com

Just to follow up: this repair is done, and it came out great. The turnbuckle worked beautifully... I was able to dial in the right neck angle with much greater precision than I could with a clamp at the headstock. The UTB had failed only under the fingerboard between where the top had cracked. I was able to jimmy it open just enough where I had room to slide a piece of sandpaper under it to clear out the old glue, then I worked in some new hide glue and it's good as new. The popsicle brace was a pain to get out with the UTB in place but with patience and heat I prevailed and replaced it with a new one with more gluing surface area. I also added a spruce patch under the rosette and epoxied a couple of small blocks to the top and the heel block for extra insurance.

I think the best thing I got from the repair was a new tool. I took a hunk of steel and drilled it to where I could attach it to a cam clamp with a screw and nut. It easily swivels to be able to fit any angle which certainly comes in handy when you have to work quickly and blindly inside the box. It came in handy to clamp a heating blanket to the underside of the top to preheat things for gluing. I also used it to heat up the popsicle brace to loosen the old glue joint by heating the steel on a hotplate, then attaching to the clamp and positioning it inside the box. Certainly nothing revolutionary, but another helpful tool in the arsenal.





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