MIMF

Hi folks,

I'm back with an old es300 Gibson that's have a bumped side on the lower bout close to the tail bloc. Not difficult to fix on a flat-top but on this old archtop with almost no entrance excepted F-holes and/or pickup. I've tried with a wood large wood shim in shape to push the side with a stick trough the F hole without success and another one with a smaller wood shim in shape strapped with nylon wire drawn from the outside.

before removing the back, have you any other ideas?

thanks in advance,

C.

Fortunately the guitar is a sunburst finish. It is difficult to see from your photos what I need to see. Better camera angles and better lighting might help.

Certainly access to make repairs is greatly improved if the back is removed. The main danger for removing the back is releasing the neck and tail blocks. I usually consider the kerfed lining as expendable and replace it with new lining material. For an older instrument like this I swab the new lining material with coffee or strong tea to make it look aged. Try it on scrap to see what works before applying it to the guitar.

The second main danger for removing the back (or top) is getting everything aligned properly when gluing the back (or top) in place after the repair has been done.

Maybe a better idea will come to you.

Setting aside my fears of looking foolish:

I picture a fixture that has padded posts, one about in line with the controls, the other near the tail block. Remove the pick-up, etc. and insert a shaped stick through the pick up hole. This will need something to push against in the upper (bass) bout area. I don't know if you can get the stick to angle down enough to push the offending area.

Or make 2 shaped cauls that will fit on the end of 2 threaded rods, that you (the emphasis on YOU) have inserted in the guitar. Attached the two rods with a turnbuckle and apply pressure to the desired area. The cauls bear on the depressed area and the upper bass bout.

It all makes sense sitting in front of my computer.

Nice guitar!

Thanks guys,

Joshua, don't you think it could be a good idea to make exteranl cauls pressed with a big cam not to deform the upper bout side?

Cedric, Let me preface this by saying I have not done this but I am willing to brain storm. Both you and Michael Lewis are far more experienced than I am.
But...
I think it is too extreme to remove the back, with all the attendant hazards Michael described, to glue up a few inches of loose seam. I have continued to think about this and while the internal fixture might work, getting everything built and set up might take close to forever.
How about this: a platform with the two padded rods or blocks on either side of the work area. Opposite the work area build a Teeter type crack puller. This is a tuning machine set at right angles to the work area (page 20 of the first Teeter book). Let me know if you can't find a diagram and I'll email something directly to you.
Make a fitted caul for the inside of the guitar. Feed an unwound guitar string through a hole over the open seam to the pick up cavity. Feed the string through the caul and affix it with a gizmo like this. Pull the bout into position, glue and clamp.

The gizmo is a piece of internally thread brass tubing with set screws on both sides. It is a bit of nostalgia from Rotosound super wound bass strings.

I was thinking the Teeter clamp also.

Interesting! I am not sure it could fit 'cause the crack is about 3"1/2 long. I am planing, if it works to use this technic adapted to archtop:
http://hamlettinstruments.com/repair-se ... ide-repair

But I keep the teeter technic close to me in case off.......

Much thanks guys and I'll let you know once done (in january, it's hollyday now...)

Josh, I get your email, thanks alot.

Cedric, now you have plenty of ideas to sift through, and you have the guitar in front of you to study for the best result. You are also aware of some dangers and hazards to temper your judgement.

One other possibility can be powerful rare earth magnets, but that would take some pondering and practice if you haven't used them previously.

Cedric, I can't offer anything but my sincere best wishes for a successful outcome. I think it's a cool guitar (even though some don't like that angled pickup on the 300). I love archtops in general and I love old Gibsons in particular. I hope you will document your repair and post it here so we can all learn from your experience. There are few things in guitar repair as satisfying to me as someone making a good save on an instrument like that 300.

Hi fellows,

I am fixing this guitar this week and coming week. I'll detail my way to do it in few days.

I am back !

first during my inspection of this big baby, I was stunned to see how those guys in gibson build this ES300. it seems to be a Super 400 to which it is cut a pickup hole. they had cut thru the bracing !!!


back to the repair:

First thanks to this pickup hole

I decided to use this inner system pushing rod




with exterior shims (with cork protection) on each side to prevent deformations of the sides





Unfortunatly, the pickup hole was not big enought to put enought tension on the inner rod with my fingers.
I deceided to use standard nut and washer like this:





and it was much better.

after that I used wood cams to glue in place the side with Hot Hide glue.

The result is perfect

I had to replace a piece of kerfing that I shaped and tinted with some tea (earl gray ) and I put it in place with a violin tool and hot hide glue. I maintained presure with my hand on the tool.







even if it seems clearer, the kerfing has the same color (thanks to the lightning)




working inside this guitar was not easy but much thanks to this pickup hole as small as it is.

This guitar sound prety nice in acoustic even with those cut braces! the pickup position gives it lots of trebles and attack but thanks to the tone pot that smouth all this agressivity.

Nice experience.

Good work!

Yes, good job!

Cedric, can you show the outside of the repair now? And especially after it is cleaned up and all finish work is complete.

I am surprised you could get your spreading fixture inside the guitar. I think you are careful, tenacious, and resourceful, good qualities to have for this profession.

Unfortunatly, the customer picked up his baby just after the repair was done...
I had to scape a bit of the binding (say 0,05") to make it flush. I used stewmac color tone and some nitrocellulose varnish to match the yellowish color of the binding.

Fixture could not be bigger in any way, it was roughly made with the band saw to fit the guitar