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PostPosted: Fri Sep 24, 2021 5:07 am 
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Walnut
Walnut

Joined: Thu Sep 23, 2021 5:25 am
Posts: 5
First name: John
Last Name: Preston
City: APO
State: AP
Zip/Postal Code: 96260-5748
Country: Korea
Focus: Repair
Status: Amateur
Mid 1960s Harmony Archtop, the top and side is separated in two places. In this case it isn't a simple matter of gluing them back together. The side has shrunk away from alignment with the top. I'm guessing the only way to fix it is to take the back off and brace the side back in place.

I'm looking for recommendations on how to remove the back.


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PostPosted: Fri Sep 24, 2021 7:41 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: 12971
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Harmony guitars were built with HHG and as such the same techniques for working with softening HHG apply. Heat, steam, water, heated pallet knives, time, patience and frustration.

As for if you are correct if this, removing he back is the only way to fix it I need pictures to comment on that.

Welcome to the forum too.

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Ann Arbor Guitars


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PostPosted: Fri Sep 24, 2021 8:09 am 
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Cocobolo
Cocobolo

Joined: Thu Nov 27, 2014 10:35 am
Posts: 356
Location: Hopkinton, MA
First name: Robert
Last Name: Ionta
City: Hopkinton
State: Massachusetts
Zip/Postal Code: 01748
Country: USA
Focus: Build
Status: Amateur
I removed the back from a 1955 Kaye archtop by just peeling the binding off (small knife and my fingers) and slipping a palette knife between back and lining. I was prepared to use heat and moisture but after about 5 minutes of wiggling the dry knife around, the back was off. It took a little extra persuasion around the tail block and left a tiny wedge of the block on the top, but no other splintering or cracks. The plywood back is fairly tough. The glue joint was not.


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PostPosted: Fri Sep 24, 2021 7:37 pm 
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Walnut
Walnut

Joined: Thu Sep 23, 2021 5:25 am
Posts: 5
First name: John
Last Name: Preston
City: APO
State: AP
Zip/Postal Code: 96260-5748
Country: Korea
Focus: Repair
Status: Amateur
Hesh wrote:
Harmony guitars were built with HHG and as such the same techniques for working with softening HHG apply. Heat, steam, water, heated pallet knives, time, patience and frustration.

As for if you are correct if this, removing he back is the only way to fix it I need pictures to comment on that.

Welcome to the forum too.

Thanks, I am definitely not a luthier, just an old guy who likes to try to fix stuff. :-) Here are some photos. Let me know if you need to different angle. There is no binding on this guitar, just painted edges.


You do not have the required permissions to view the files attached to this post.


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PostPosted: Fri Sep 24, 2021 7:40 pm 
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Walnut
Walnut

Joined: Thu Sep 23, 2021 5:25 am
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First name: John
Last Name: Preston
City: APO
State: AP
Zip/Postal Code: 96260-5748
Country: Korea
Focus: Repair
Status: Amateur
bionta wrote:
I removed the back from a 1955 Kaye archtop by just peeling the binding off (small knife and my fingers) and slipping a palette knife between back and lining. I was prepared to use heat and moisture but after about 5 minutes of wiggling the dry knife around, the back was off. It took a little extra persuasion around the tail block and left a tiny wedge of the block on the top, but no other splintering or cracks. The plywood back is fairly tough. The glue joint was not.


Thanks, I'm thinking that is the way to do this one. I want to be prepared to use heat and moisture but I don't know how much heat and or moisture or how to apply.

This guitar doesn't have a binding per se, it is just painted on the edges.


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PostPosted: Sat Sep 25, 2021 3:49 pm 
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Cocobolo
Cocobolo

Joined: Thu Nov 27, 2014 10:35 am
Posts: 356
Location: Hopkinton, MA
First name: Robert
Last Name: Ionta
City: Hopkinton
State: Massachusetts
Zip/Postal Code: 01748
Country: USA
Focus: Build
Status: Amateur
waegwan wrote:
bionta wrote:
I removed the back from a 1955 Kaye archtop by just peeling the binding off (small knife and my fingers) and slipping a palette knife between back and lining. I was prepared to use heat and moisture but after about 5 minutes of wiggling the dry knife around, the back was off. It took a little extra persuasion around the tail block and left a tiny wedge of the block on the top, but no other splintering or cracks. The plywood back is fairly tough. The glue joint was not.


Thanks, I'm thinking that is the way to do this one. I want to be prepared to use heat and moisture but I don't know how much heat and or moisture or how to apply.

This guitar doesn't have a binding per se, it is just painted on the edges.


I’m also an amateur so take my story with a hefty grain of salt! I should have started off with that caveat. I’ve done exactly 1 back removal. It was easy but maybe yours won’t be.

My way of applying heat was going to be by heating my palette knife in hot water (about 150-160 deg. F). I figured on using a pipette to dribble tiny amounts of water along the joint. I also had a variable temp heat gun standing by in case that didn’t work but I was nervous about damaging the finish with that so I’m glad I didn’t have to use it.

BTW when I re-attached the back I had the problem of the sides having gone wonky and not matching the outline. I dealt with that by tracing the back onto a piece of plywood and cutting a form to go around the body to force it back into shape. In a couple of places I screwed small blocks to the plywood to exert a little more pressure. It was sort of like squeezing the balloon over here to make it bulge out over there until it matched the back. It was a hassle but it worked out with a lot of fussing around.


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PostPosted: Sat Sep 25, 2021 5:03 pm 
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Contributing Member
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Joined: Fri Jan 11, 2013 2:26 pm
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First name: Carl
Last Name: Dickinson
City: Forest Ranch
State: California
Zip/Postal Code: 95942
Country: USA
Focus: Build
Status: Amateur
Make the mold before you take the back off. Notch it to fit around the neck heel. Have it on while you do the top/side repair so the sides don't get out of shape while the back is off.



These users thanked the author CarlD for the post: bionta (Sat Sep 25, 2021 5:57 pm)
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PostPosted: Sat Sep 25, 2021 7:30 pm 
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Walnut
Walnut

Joined: Thu Sep 23, 2021 5:25 am
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First name: John
Last Name: Preston
City: APO
State: AP
Zip/Postal Code: 96260-5748
Country: Korea
Focus: Repair
Status: Amateur
bionta wrote:
waegwan wrote:
bionta wrote:
I removed the back from a 1955 Kaye archtop by just peeling the binding off (small knife and my fingers) and slipping a palette knife between back and lining. I was prepared to use heat and moisture but after about 5 minutes of wiggling the dry knife around, the back was off. It took a little extra persuasion around the tail block and left a tiny wedge of the block on the top, but no other splintering or cracks. The plywood back is fairly tough. The glue joint was not.


Thanks, I'm thinking that is the way to do this one. I want to be prepared to use heat and moisture but I don't know how much heat and or moisture or how to apply.

This guitar doesn't have a binding per se, it is just painted on the edges.


I’m also an amateur so take my story with a hefty grain of salt! I should have started off with that caveat. I’ve done exactly 1 back removal. It was easy but maybe yours won’t be.

My way of applying heat was going to be by heating my palette knife in hot water (about 150-160 deg. F). I figured on using a pipette to dribble tiny amounts of water along the joint. I also had a variable temp heat gun standing by in case that didn’t work but I was nervous about damaging the finish with that so I’m glad I didn’t have to use it.

BTW when I re-attached the back I had the problem of the sides having gone wonky and not matching the outline. I dealt with that by tracing the back onto a piece of plywood and cutting a form to go around the body to force it back into shape. In a couple of places I screwed small blocks to the plywood to exert a little more pressure. It was sort of like squeezing the balloon over here to make it bulge out over there until it matched the back. It was a hassle but it worked out with a lot of fussing around.


Thanks, this is exactly the kind of help I was looking for. I had not considered making a mold with plywood but that sounds like the perfect thing to do. I have plywood and a good jig-saw. This will be an interesting project this winter. :-)


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PostPosted: Sat Sep 25, 2021 7:32 pm 
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Walnut
Walnut

Joined: Thu Sep 23, 2021 5:25 am
Posts: 5
First name: John
Last Name: Preston
City: APO
State: AP
Zip/Postal Code: 96260-5748
Country: Korea
Focus: Repair
Status: Amateur
CarlD wrote:
Make the mold before you take the back off. Notch it to fit around the neck heel. Have it on while you do the top/side repair so the sides don't get out of shape while the back is off.


Excellent advice, Thanks :-)


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