Acme Bowlback repair

Ladies and Gentlemen,
First off I hope everyone has a happy and safe Thanksgiving.
I picked this one up at an estate sale on Saturday. It needs some work and hopefully can be turned back into a player again. I posted it in the looking for information section as I didn't know what it was and NickR pointed me to an older thread where Jim Garber had an almost identical model with a label attached. So, here we go. Going over it carefully at home I was surprised to see glue along the edges of almost all the MOP and Abalone inlays. It almost looked like someone had re-glued them in and not done a cleanup. Under the tailpiece the wood was crushed and looked like it had been slathered with glue to hold it together. Amber colored glue which cleaned off nicely from the inlays with white vinegar. The vinegar also really cleaned up the inlays and brought them back to life.Looking closely at the tailpiece area it looks like the inlays are stuffed in there, albeit at an angle and glue covered. Upon reflection I believe no one had attempted any repair but the instrument had sat strung up for possibly decades in an unconditioned attic in the south, probably here in Alabama, and the damage is entirely self inflicted. It got hot enough to cause what looked like glue squeeze out. For those never having spent a summer here the last place you wish to go is the attic on a 95-100 degree day. Brutal is not sufficient.

Here are the problems I'm facing in what I think the most important order:

1. The neck is not bowed as much as I would call a curved kink. Fret board is flat from 1-10 and 17-11 both sloping to the neck joint. At 10 and 11 distance from straight edge to frets is .024"/.60mm. Neck to body joint looks and feels solid. I saw a video on you tube where a guy straightened a neck using a U type band clamp, a square piece of steel tubing and a bag full of uncooked rice heated in the microwave. I'm wondering if this could be done here without a neck or fingerboard removal because I don't think the fret board will survive( I haven't put any oil on the fret board yet but is obviously in desperate need) being liberated from its' present position. Was planning on doing this ever so slowly over the course of at least several days gradually adding tension. Thoughts on this or am I in way over my head?

2. Tailpiece area repair. Since the glue cleans up so well with vinegar I was thinking of trying laying a very damp cloth on the area and using a rheostat controlled pencil type soldering iron set to 200-250 to heat it up to loosen the glue and retrieve the inlay pieces and clean out and straighten the inlay channel. Also will need to clean out under the top and re-glue.

3. Same as above with the inlay at the sound hole but just gently pressing them back in place.

Here are some photos Showing the glue at the inlay on the head stock, the tail piece area and sound hole inlays.

Thanks for any help and suggestions you can give me.

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Hi David,

A very interesting piece! I've been playing with bowl backs a bit recently and can offer a few thoughts... Use abuse or ignore as you see fit.

First of all, what you have is an instrument with an "ebonized" fingerboard. This is a chemical process used to treat cheap wood such as maple or pearwood and make it appear black like ebony. It was commonly used on inexpensive and student grade instruments and I believe it involved an acid which, over time, deteriorates the wood. I would stabilize the board as best I can, with superglue (20 or 30 thickness) to re-glue the board together and fill any gaps. This may take some time and multiple applications; I expect there are some Youtube videos out there on the subject. This is very important if you want to save the board. Things will get quite complicated if you need to remove the board later so if at all possible, be careful to avoid getting glue under the fingerboard as you do this. If it's loose from the top, slip a piece of wax paper between the fingerboard and the guitar top to keep those parts separated. Without this superglue treatment, the fingerboard will simply disintegrate if you try to remove it or take out any frets. Don't underestimate how fragile this is!

Next, regarding the collapsed area by the tailpiece, as you suggested, it looks like the inlay pearl has simply twisted vertically and is still there. I'd use moisture in the form of a wet paper towel on the area overnight, then heating slowly with a hair dryer until you loosen the glue and can retrieve the pearl pieces. Add water as needed. Wood has a memory and it may begin to return to it's original shape. Rebuild any damaged support wood and be sure to check and make sure the end block is still securely glued in place (I expect it's come loose at the top).

Looks like a lot of the inlay was loose and was glued in place just to hold it together. Not a big deal. Remove the old glue (heat, moisture, vinegar, etc), re-seat then old inlay and re-glue. Thin superglue is great if the old glue isn't an issue. It will take some time but should work fine.

While it's a fancy instrument, the ebonized wood and the mediocre quality of the inlay engraving, and the silver wire stems rather than pearl in of the "vine of life" suggests a high end, budget instrument. If you can stabilize the fretboard, you just may be able to bring it back to life.

Good luck!