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 Post subject: Advice on a Martin Neck
PostPosted: Sat Jul 14, 2018 6:56 pm 
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Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
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State: Texas
Country: United States
Focus: Repair
I have a 69 D35 in the shop. Initial cause of concern was that there was a crack in the neck about 1 1/2" from the heel. Owner informed me that the crack had been glued about 4 previous times and had continually come undone.

My course of action was to remove the whole neck, seprate the two pieces, scrape out whatever contamination is present, reglue with hide glue, reinstall the neck, call it done.

The top portion of the neck came out just fine. However the heel portion simply will not budge. I have the stew mac neck removal jig and it it simply not moving with the steam injection method.

Feeling around the heel it looks like some previous home gamer decided to glue the outer edge of the heel the sides of the body. I ran a pallet knife around the edge to sever the hold it had on the neck. I also took a thin feeler gauge to create some clearance between the sides of the neck block and the dovetail. Still not budging.

Plan F at this point is to reglue the neck to the heel portion after removing the crud from previous glue attempts, waxing the exposed portions of the dovetail block so I don't glue it back to the dovetail. then use the extra torque from the neck and try steam again but deeper in the joint.

What I think has happened is that the lower portion of the dovetail was fit WAY too friggin tight with no space for movement as the wood contracted over time. The upper portion was not fit so well so it moved all over the place while the lower part stayed fit. This is just my thought as I could be wrong but there is definitely something amiss with the upper and lower portion of the dovetail.

My question is, has anyone run into a problem like this before, and how did you resolve it?


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PostPosted: Sun Jul 15, 2018 5:18 am 
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Brazilian Rosewood
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Location: Magnolia DE
First name: Brian
Last Name: Howard
City: Magnolia
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Zip/Postal Code: 19962
Country: United States
Focus: Repair
Status: Professional
My approach would likely be to use a drill and waste out the center of the tennon on the broken heel so it can be steamed and worked out. A injection hole in each side right down the joint line for a steam needle will help. you can work the edges of the joint inward and free the piece then just replace the section in the center you wasted out after you glue the heel back on the neck and you're almost home.

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You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/



These users thanked the author B. Howard for the post: DanKirkland (Sun Jul 15, 2018 2:18 pm)
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PostPosted: Sun Jul 15, 2018 2:46 pm 
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Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
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State: Texas
Country: United States
Focus: Repair
B. Howard wrote:
My approach would likely be to use a drill and waste out the center of the tennon on the broken heel so it can be steamed and worked out. A injection hole in each side right down the joint line for a steam needle will help. you can work the edges of the joint inward and free the piece then just replace the section in the center you wasted out after you glue the heel back on the neck and you're almost home.


Thanks for that Brian. Just a follow up thought but in replacing the drilled out portion is it wise to maybe add a few tiny dowels so the replacement mahogany doesn't come unglued when the neck needs resetting again?


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PostPosted: Mon Jul 16, 2018 5:27 am 
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Brazilian Rosewood
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Location: Magnolia DE
First name: Brian
Last Name: Howard
City: Magnolia
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Zip/Postal Code: 19962
Country: United States
Focus: Repair
Status: Professional
i would not add any dowels myself. Don't want the graft to come loose on the next reset? Epoxy that part then.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/



These users thanked the author B. Howard for the post: DanKirkland (Mon Jul 16, 2018 9:20 am)
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