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 Post subject: beginner repair question
PostPosted: Sun Feb 20, 2022 8:05 pm 
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Walnut
Walnut

Joined: Sun Feb 20, 2022 4:00 pm
Posts: 1
First name: David
Last Name: Union
City: Shrewsbury
Zip/Postal Code: 01545
Country: United States
Focus: Repair
Status: Amateur
my project of fixing my old guitar (old harmony) got stalled nearly complete. It needed a neck reset and some hardware, it was really never straight from the factory and got worse over the years. It was used when I got it around '72 or so and not worth paying the luthier to fix it.

So I got the neck off with some help, got the neck straight and carefully made some room as per some reading on this to adjust the fit back. Now I need to figure exactly what angle to put it on while the strings are off so when the strings are on it is correct. If I take a straight edge over the frets and run it to the bridge, do I line the bottom of that stick (which is along the top of the fret bars) with the top of the bridge or the bottom of the bridge or somewhere else?

Once I know that I can put in the wood shims, sand down and re-glue...

Thanks.
Trial and Error beginner :)


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PostPosted: Mon Feb 21, 2022 5:56 am 
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Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
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Joined: Fri Nov 02, 2007 9:49 am
Posts: 13387
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Hi David and welcome to the OLF..

Here's some tips from me and good on ya for resetting a proper dovetail. Old Harmony guitars are what people should be learning neck resets on because the dovetail is very much as Martin and others who may need resets too and are economically worth doing.

I like to line the straight edge up with the top edge of the bridge plus the fret height that the straight edge sits on. This is a very slightly amount overset and I do this intentionally since things will settle in and someone may use 13's on it too. So if your frets are .040" high the straight edge comes in perhaps .030" - .040" above the bridge top.

So be sure the neck is as straight as possible before using the straight edge and you said, thanks too, that you already did and do this.

I'll add make sure the neck is correct left to right too. I do that by making a mark on top of the bridge between the D and G and that's the bridge center. Then I use masking tape in four equal distant locations on the fret board, four is better than three and mark in the tape in the exact center of the fret board. Then my straight edge is registered on all four neck marks and the bridge center mark. Now your neck is perfectly straight left to right.

Last tip is we like to fit the dovetail as it's intended to do all the work mechanically and not have any dependency on glue for strength. The glue is there only to keep the dove tail in place and make you and I pull out our hair come next reset time :)

The lowest part of the dovetail is the business end the keeps the neck in place and not folding into the guitar under string tension. So very important to get a good, tight fit with the dovetail alone with no glue. We like it when a bit of a tonk is required with a fretting hammer to finally seat the neck in the dovetail. We do use glue but only to hold the dovetail fully seated. Avoid excess glue, always.

If the neck can be manipulated away from the guitar side cheeks manually especially at the lowest part of the dovetail snugger and better fit and shimming is required before final set. Fitting is an art of sneaking up on the perfect fit over time and with material removal from the shims.

And one more tip since I can't quit :). Mohogany shim strips we CA to the dovetail and then carve them back as we fit with CHALK :) not caulk, sheesh what. geezer I am....

Good luck and again welcome and let me know if I can help you, I'm happy too.

PS: My first ever neck reset was a Harmony Sovereign and it all went great and the guitar was a nice player when done. Fond memories.


Last edited by Hesh on Mon Feb 21, 2022 2:46 pm, edited 1 time in total.

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PostPosted: Mon Feb 21, 2022 12:38 pm 
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Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Hesh wrote:
And one more tip since I can't quit :). Mohogany shim strips we CA to the dovetail and then carve them back as we fit with caulk.


Hesh you mean chalk, and not caulk right? My wife hates it when I'm technical, but in this case I figured this might be an important distinction. ;)



These users thanked the author Conor_Searl for the post: Hesh (Mon Feb 21, 2022 2:43 pm)
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PostPosted: Mon Feb 21, 2022 2:44 pm 
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Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
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Joined: Fri Nov 02, 2007 9:49 am
Posts: 13387
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Conor_Searl wrote:
Hesh wrote:
And one more tip since I can't quit :). Mohogany shim strips we CA to the dovetail and then carve them back as we fit with caulk.


Hesh you mean chalk, and not caulk right? My wife hates it when I'm technical, but in this case I figured this might be an important distinction. ;)


Yeah Connor my friend thanks for reminding me I need new glasses :). Going to edit it now but thanks for pointing it out.


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