damaged dovetail

Even if it ain't broke you can still fix it.
lonecedar959
Posts: 50
Joined: Tue May 09, 2017 5:34 am

damaged dovetail

Post by lonecedar959 »

Hi

This is the neck from an Airline 7032 (Harmony Sovereign clone). The dovetail tenon is slightly damaged on the very front.

Does it matter? Can I go forward with the neck reset without having to repair it or should I glue a piece in there and shape it?

No - I dont have the missing piece.

Thanks

-Pat
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MaineGeezer
Posts: 1359
Joined: Wed Aug 13, 2014 12:14 pm

Re: damaged dovetail

Post by MaineGeezer »

I don't have enough experience to know, but in my ignorance I might do something like this. Uniformly shave some amount off the beat-up dovetail surface and glue on another face piece, making it thick enough to either cut away the bad areas entirely, or at least thick enough so it is sufficiently strong to bridge over the bad spots. I've drawn it going the full length, although I suppose it doesm't have to. It might be easier to cut it that way though.

Before doing this, I think I would wait for a second opinion. You may not need to do anything. I can't offer a solid opinion about that just from the pictures. but you most definitely do not need perfect mating surfaces.
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lonecedar959
Posts: 50
Joined: Tue May 09, 2017 5:34 am

Re: damaged dovetail

Post by lonecedar959 »

Thanks Mainegeezer - I should have clarified that picture a little. Its the top of the tenon that I am concerned about (circled in Red). The chunk half way down (circled in blue) I have that piece and will be gluiing it back on. The rest of the tenon is the way it was when it came out of the mortise.
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MaineGeezer
Posts: 1359
Joined: Wed Aug 13, 2014 12:14 pm

Re: damaged dovetail

Post by MaineGeezer »

If it's the way it appears to be, I don't think you need to worry about it. Put it together annd call it a day.

Perhaps, however, one one of the more experienced members will explain how they would do the repair, if one did want to repair it.
Y
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Location: Hegins, Pa
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Re: damaged dovetail

Post by tippie53 »

I run into this pretty often and what I do is clean up the tenon and glue on an over sized shim , it should be fine I keep the angle of the original tenon.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
ruby@magpage.com
Posts: 1542
Joined: Thu May 24, 2012 8:03 am
Location: Chestertown Maryland

Re: damaged dovetail

Post by ruby@magpage.com »

Remember that the bottom of the dovetail is the area that does the work. The force of the strings is trying to pull the bottom away from the body. The top area is being pushed in towards the body, so that area only needs to stabilize the joint.

Ed
Ed M
lonecedar959
Posts: 50
Joined: Tue May 09, 2017 5:34 am

Re: damaged dovetail

Post by lonecedar959 »

Thanks everyone -

I didn't think it was too serious.

John I believe I will do what you suggest.

Thanks

-Pat
tippie53
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Re: damaged dovetail

Post by tippie53 »

actually the bottom of the dovetail doesn't or should not be in contact with the block. The dovetail is an interference fit joint. Martin only uses the sides of the dove tail. The joint needs to have clean contact on the sides. I only did a few thousand of these joints . I used to think early you want the dovetail to be perfect all around but that was proven wrong early.
I show this in this video
https://www.youtube.com/watch?v=FNcbA1P95KE&t=30s
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
tippie53
Posts: 6444
Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: damaged dovetail

Post by tippie53 »

Ed
did you mean the deeper part of the tenon ? Not the point of the vee.
in that point you would be 100% correct
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
ruby@magpage.com
Posts: 1542
Joined: Thu May 24, 2012 8:03 am
Location: Chestertown Maryland

Re: damaged dovetail

Post by ruby@magpage.com »

John

The point of the V, the bottom half of the joint, is the one with the strain pulling on the dovetail. On the upper half, the cheeks of the neck, on the outside of the body just below the fretboard, the joint is pushed together.

That's why my single bolt down low in a bolted M+T neck works. I posed this idea in another forum and got a whole bunch of luthiers saying they do a singe bolt also.

Ed
Ed M
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