Hello everyone. I'm new here. I recently got my hands on a beautiful Gibson A2 mandolin. I went on vacation (the mandolin was left in the case at home while I was gone) for a few weeks, got home and saw that the binding was coming off a bit. I'd like to repair it- I figure it's a quick easy fix. I'd just like a bit of knowledge on how to do so correctly. Any suggestions and advice would be greatly appreciated. Thank you!
I asked a luthier friend what he uses to do this type of repair as I was facing the same issue. I had tried various glues in the past that worked well for applying new binding but found I needed something different for repairs. In my case, the binding needed heated gently before I applied pressure while gluing. Loctite Super Glue Professional is the glue that my friend uses and I found it to be very effective. Great care should be taken to mask the finish areas (a low tack masking tape), I used an A shaped plywood cutout to surround the instrument with just enough room to use several small wooden wedges to press the binding against the channel. Great care needs to be taken if you're using a hair dryer to warm up the binding (if it has shrunk and pulled away).
Thank you for the reply. The plywood cutout with wedges is a great idea! Any way to apply heat besides a hair dryer? I'm assuming the binding has shrunk. I also asked my luthier friend what to do and he basically said the same thing as you- just with less details. Said the trick was applying heat without damaging the finish... is that what the masking tape is for? Anything else I could use in addition to masking tape?
I don't think you need much heat, it's best to not use much due to the nature of the celluloid binding (flammable/combustible). I'd be nervous touching the binding with anything that would be too warm/hot. Most hair dryers don't approach the heat temp that hot air guns do, thus a bit safer. The tape is mostly to protect the finish from glue. Again, low tack is important as I've had blue masking tape pull off the finish on old finishes. Perhaps tape some strips of cardboard over the taped area to lessen the heat from affecting the instrument's finish.
If the binding doesn't press into place snugly, even if you've heated it, glue will not hold reliably, or you might break the binding.
--also--
Sometimes when the binding pulls away in that area on an old A model, the side is also pulling away from the neck block.
If you can insert a pin into the gap that's deeper than the binding, the instrument will have to be repaired by someone with experience with the job.
I urge caution. Loose binding always looks like a simple fix, but it often isn't. I would entrust it to someone with experience doing this repair.
If the binding hasn't shrunk and presses easily back into the channel, the issue of glue marring your finish is real. An errant drop of superglue is all it takes. It takes practice to get the taping right. Depending on the condition of your mandolin, you may or may not want to practice on it. I generally use Duco Cement for this repair. Same potential finish issues. I have used Titebond with success. It generally doesn't affect the finish, but if the binding is shrunk a little it may not hold.
The photo looks to me like the binding has shrunk. Heat has the possibility of loosening more glue and binding, as well as causing it to break easier. Like most repairs, where someone attempted to glue the binding without success, the problem can just get much bigger. IMO, experience is the key to this repair.
Old celluloid binding generally doesn't stretch very well once it has shrunk. Most of the glues that will hold celluloid to wood really well are invasive to finishes.
If the binding has shrunk very much, it is sometimes necessary to cut it in a strategic place, glue it, and fill the gap caused by the cut with a piece of new celluloid. The process is fairly easy if you know a few tricks. The problem is getting a good finish match on the filler piece.
Yes, best left to a pro who is experienced with the job.
In order for a re-glue to reliably hold, the binding must be over-stretched for gluing. Simply heating and stretching back into place is not usually enough and the binding will once again pull away from the wood.
There are 2 remedies:
1. release the binding to each side of the loose section and place shaped shims under the binding to each side so that it can be heated and over-stretched, then re-glue.
2. cut the binding and piece in a matching piece.
Neither of those is a repair recommended to an inexperienced person, so taking it to a competent repair person is the best path.
I know this is a redundant post, but this is a good place for redundancy.
It takes a lot of heat to stretch most plastic binding materials-- 150 to 200+ degrees.
Enough to cook glue and finishes.
These days I usually prefer to insert a filler piece.
See Frank Ford's techniques at www.frets.com.
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