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Sunken top on a late romantic guitar http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=26407	Page 1 of 1

Author:	spiderjames [ Mon Mar 08, 2010 8:28 am ]
Post subject:	Sunken top on a late romantic guitar
Hello everyone. I have been lurking here for some tome and have found some great help for my guitar repairs and setups. Thanks. Lately I decided to pull out a 1850ish guitar that I have had in my closet for a couple of years and want to get it playable. I was told it was probably of Bavarian origin, a common "house guitar" built by a luthier or cabinet maker for a local working class citizen. It has Bar frets, a small body, and a figure eight headstock with peg tuners. Not a valuable guitar but I would like to get it playable and enjoy it. Somewhere along the way the bridge was changed and it was strung with steel strings Who knows how long it sat in less than ideal humidity. It suffers from a few maladies #1) Top is sunken in a from the sound hole forward and just forward of the bridge. About 3 mm at the deepest near the sound n hole and a mm or so near the bridge. the guitar shows some signs of dryness and although there are no cracks in the top the brace are protruding slightly from the sides forcing the back loose at one spot. #2) the neck is twisted slightly colckwise as you look from the headstock i have been humidifying if for too weeks with little positive results. The top is still sunken and distorted. I am guessing that since there are no cracks in the top that most of the damage was from the steel strings. Any way to correct this without opening the guitar? If I could bring the top up at least some I could shim the fretboard and plane out the twist and it would be playable again. Any help greatly appreciated. James

Author:	spiderjames [ Tue Mar 09, 2010 9:08 pm ]
Post subject:	Re: Sunken top on a late romantic guitar
OK. Here's what I am trying and it looks like it just may work. I put spool clamps around the edge of the guitar to keep the guitar from coming apart. Then I slightly dampened the top where it was sunken in and using wood blocks and wedges as a jack I applied gently pressure between the top and bottom braces. Then I applied heat to the top until the area was thuroughly heated. I repeated the process this morning and this evening leaving the jack in place. The top appears to be responding I will repeat every morning and evening slowly edging the top up over the nect several weeks until there is a slight crown ( assuming it will try to drop a bit later). I will then shim the fretboard, plane out the warp and refret. I think it will work if I take my time. here's what it look like so far:

Author:	Blain [ Tue Mar 09, 2010 10:53 pm ]
Post subject:	Re: Sunken top on a late romantic guitar
Hey James, Welcome to the OLF. I don't really have advice for you so much as I just wanted to share what I saw at Guitar Center once on a Guitar (forget the maker) that was cut in half to show the inside. The guitar had a Rod of some sort coming from the Tail block (inside the guitar) straight towards the bridge area. Then it 90 degreed to the underside of the bridge (or to the bridgeplate rather). If my memory serves me correctly it was almost like tinker toys. One rod/dowel type object straight into the heel block, then a block that basically acted as a 90 degree elbow which had the other rod going up to the bridge. This basically was intended to support the top to keep it from sinking (my guess). Anyway, not sure that's really what you're looking for since it doesn't look like you're planning on tearing this one apart, but they've used heat and force to persuade necks so I don't see why that shouldn't work for a top as well. Good luck and keep us posted on your progress.

Author:	StevenWheeler [ Tue Mar 09, 2010 11:54 pm ]
Post subject:	Re: Sunken top on a late romantic guitar
James, Welcome to the party! Blain is thinking of the Bridge Doctor as used on Breedlove Guitars. It can be found at Stewart-MacDonald. I think you've got a good start there. Slow and steady will win this race. I was thinking along the same lines for a cheap (real cheap) made in Mexico for the local tourist trade guitar I have that has suffered the same fate. Make sure the the back is well supported so you don't flex it while trying to move the top. Keep the temperature and moisture in check, you don't want the glue to let loose. Hey Guys! How much heat will hide glue withstand? Steve

Author:	spiderjames [ Thu Mar 11, 2010 12:30 pm ]
Post subject:	Re: Sunken top on a late romantic guitar
Thanks for the responses. I am tring to move as slow as possible. not letting my impatience get the better of me. I will continue to post as the progress continues to its final outcome, good or bad. I saw the bridge doctor and I will be improvising a similar device to dri to drive up the top under the leading edge of the bridge. I also thought about the idea of putting a soundpost like a violin under the bridge to lift the top. I have often wondered why guitar do not have them.

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