FIrst of all, I want to say a special thanks to Frank Ford and Hesh Breakstone for the thoughtful guidance in steering my away from power tools in this project. Its amazing how your plan of action will change drastically once you get sage advice from every experienced luthier you can who has done the task you are about to undertake, and then the next step is to actually get the thing on the bench and sink a chisel into the issue.
Chisel, indeed! I was experimenting with heating up the binding with a hair dryer before trying to chip it off, and found a 4th layer of thin black binding under the dark sunburst back finish.when I tried wedging my chisel behind that i was amazed to see that by carefully wedging a chisel between the black layer and the edge of the back, the glue joint between the binding and the wood in the binding slot on both the back's edge and the top of the rib gave way rather easily....and cleanly! Its coming off by this method of simply wedging it off slowly and carefully on big sections...4-5" at a a time!
I have yet to see any binding slot damage other than some very superficial grain tearout on the edge of the back very occasionally. There will be some tiny chips of finish along the edge of the binding slot which will have to be touched up before the binding can be replaced, but I am told that that is to be expected anyway. I was afraid that any attempt to pre-score the finish might look worse than the chipping I was trying to avoid, so I havent done that yet. Perhaps I will give that a shot.
I am sure that each of these rebinding jobs are different, and I think I got one that had either a poor glue job in the binding slots, or one in which the gassing out of the binding layers weakened the glue joint between the wood in the slot and the plastic binding.
Either way, I feel like I am cheating. It took me less than 30 minutes to clear the binding ( I took the crumbly stuff out first) out of the binding slot on the whole back. I was prepared to go an couple of inches an hour.
Nice to hear that it's going great Joseph and you are very welcome too!
Scoring is just as you said yourself, each job can be different. With some old lacquer or perhaps lacquer that had adhesion issues all along scoring can be worse as you thought it can be. With other examples, not so much and we never know until we attempt to find the least visible, destructive area and give it a shot.
Just wanted to say good going to you.