Sunken tops on flattops

[Jim Garber]

I have a Vega cylinder back that has a sunken top. Aside form the aesthetics, I was wondering if I can determine how stable that top it.

In addition, is there some solution to fixing or propping up the top so it doesn't get worse? or, even better, is there some solution to fixing it altogether besides making a whole new top. I don't think I would be up to doing that whole surgical procedure myself -- my experience is somewhat limited. On the oither hand I don't think I want to spend serious luthier dollars having someone truly competent do it.

Jim

[Eugene]

I think I would at least try a phone call to our chum Mr. Crandall. #I believe he has dealt with this. #If not, I know Ben Wilcox (http://www.brw-instruments.com/) did on a severe case on a friend's Wurlitzer that was almost certainly made by L&H. #Again, this case was severe, and Ben returned a worthless piece to some playability, but it couldn't be made perfect. Ben might entertain an e-mail on this...if he can take a moment off from building for his zealous fans. #Is there a brace loose, Jim, or are the braces distorted as well?

[Jim Garber]

I have to check on the interior of this mandolin. Evidentally, this is fairly common esp to these cylinder backs. I have heard fo a few that were retopped by the Rigel folks that are pretty awesome player's instruments.

It looks on mine, that most of the sinkage has occurred tailpiece-side of the cant which means beyond the cross brace.

Jim

[Dolamon]

A cheap maybe fix ... I've done this on four or five fairly early mandolins (not a cylinder back however) it does take time but that's really all it costs.

Many of these old instruments have been neglected sometimes for decades and - they dry out. If the sinking isn't too the point of fracturing wood, try humidifying it for several months. In a relatively humid basement, I've unstrung the instrument, even removed the tailpiece and the tuners and let it sit in an open case in about 50% relative humidity for a month or so. With an old Rosewood Cittern, it smelled like a wet, leaf fire for about six weeks then the scent went away and the top was glueable (it had one small crack which was now almost closed).

On one old 1919 Gibson, I had to put humidifiers inside the body for almost six months and - the top very gradually rose back up to being able to use the original bridge and no shims (I went to Black Diamond strings just to be safe). Every instrument is a bit different and even if the instrument has been fairly well cared for in the recent past - there maybe a decade or two when it was neglected.

As a final shot before replacing the tuners and tailpiece, I'll wash the body with a soft cloth dampened with some deionized water ... all the sludge is gone - and the minimal water is just replenishing the body - once more.

This process won't hurt the instrument - and may help and save you some money, but it does take time.

[MANDOLINMYSTER]

Heres a thought..Remove strings, and hardware,humidify the instrument for 4 weeks in an hermedicly sealed chamber, plug up the sound hole and slowy pump air into the body....ok, ok, hey it might work http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Luthier Vandross]

Generally, as already said, maybe, but clamps slowly tightened, using cauls, and shims.

How bad is the bubble? Can take 24 hours, or 24 weeks.


M