Cello neck Repair
This is a severe neck crack on a student Cello. No one seems to know how it happened so I will chalk it up as one of those "it happened by itself" stories I hear so often.
I will go through the basic process of repairing it. There are different ways of approaching it, and I'm sure every repairman will have their own twist on this, but I will go over a way that will get the job done properly.
No two necks will ever crack the same way, so you have to assess every break differently to determine the method of repair.
Rub Glue into Crack
There were multiple cracks in this neck. I pulled apart the neck slightly to work in some glue. The fingerboard was removed before I worked in the glue. In this situation I will use Titebond III to re-glue the neck I need to have this joint as strong and permanent as possible so I have chosen not to use Hide Glue. It is still a water soluble glue so if the break should open in the future you can remove the glue residue with water.
After examining the situation I decided to remove the fingerboard from the neck. You can use different types of spatulas to remove the fingerboard. If necessary you can start to work some water in the joint were the spatula enters to help soften the glue. Hopefully the board was glued with the proper glue in the first place. If not it can take some slow steady work to remove the board.
Gluing A Splinter
There was a small chip I had to glue separately. In this case it was a matter of a little glue and a rubber band to hold it in place.
Glue And Clamp Crack
I have glued the crack with different types of clamps and clamping blocks. This set up worked good for this particular crack, however with another cracked neck the scenario might be different. You need to adapt as you go. Take notice of the lower picture, I had to use that specific clamping block to get the crack to close up properly.
Sometimes the fingerboard doesn't come off cleanly and small pieces of the neck are still stuck to the board. You must carefully remove them and re-glue them to the neck.
Gluing The Neck
I want to temporally attach the fingerboard to the upper half of the cracked neck. The first thing I do is to cover the fingerboard with cellophane tape. I don't want the finger board glued to the neck itself at this point.
I taped the fingerboard to the upper half of the cracked neck to keep it aligned properly. Before I go any further, I need to stress how important it is to practice the next several procedures, before applying any glue. It might look easier than it is but when the glue is applied, the pieces will start to slide around making the situation more difficult.
At this point I applied glue to the crack and positioned the neck in place cleaning up any squeezed out glue as I proceeded. Next I temporarily taped the lower part of the neck and fingerboard together to start the basic alignment.
What I used next in this situation was to take a cut out strip of rubber from a bicycle tube. I tightly wrapped the neck with it watching the alignment as I proceeded. I left this overnight to dry. The next day I removed the banding and tape then proceeded to clean up any left over glue and tape residue. Sometimes when a neck is cracked straight across, I would then install a reinforcement between the two halves. In this situation the crack was long with plenty of gluing surface so I didn't deem it necessary.
Gluing On The Fingerboard
After preparing the neck and fingerboard I re-glued it with Hyde Glue. The missing chips on the back of the neck will also need to be dealt with, however that and other details will be covered in one of my upcoming books on violin repairing.