3/4 Cello Broken Neck Repair Part 3

Gluing the Parts


This is the epoxy resin used for the repair.

West System is a two-part epoxy resin that cures at room temperature as a high-strength plastic solid. The resin is mixed with pre-calibrated pumps that administer specific proportions of liquid epoxy resin and hardener. One squeeze of each pump, resin 105 and hardener 205, make 8 ounces of mix material. This resin is highly resistant to moisture, it adheres to a wide range of materials, making it ideal for projects requiring chemical resistance and impermeability. The strong physical properties of this epoxy resin makes it ideal for coating and structural bonding. Its low viscosity and penetration properties make it ideal for use in wood, fiberglass and metals. Since it doesn't shrink it is used to fill cracks. It is sandable and compatible with all types of paint or varnish.



The cello waiting for its fix.

I covered the entire edge of the area to be glued to prevent damage to the varnish by the epoxy resin. After the resin is mixed, it is applied uniformly with the fan brush. Both sides to be glued most have resin and should be left with it for at least a minute to be sure that the wood absorbs some of it. More resin should be applied before joining the two pieces if necessary.


The two sides are joined with two clamps until the resin cures and hardens. The resin cures and hardens in about 10-12 hours. All resin squeezing out of the joint drips on the tape not on the varnish, making the subsequent finishing work easier.



After about an hour I to turn the cello upside down so the resin can move to the large empty space filling the crack. With a brush I applied a bit more resin to fully seal the crack.


Here you can see the good coupling of the parts

I removed the tape at the 6th hour of curing, when the epoxy is in a rubbery semi solid state.
I recommend doing so at this moment because once the epoxy resin cures, the tape becomes extremely difficult to remove and very probable you'll need a chisel or sharp tool to do so.
At the twelfth hour the resin is cured, now we can remove the clamps. For extra precaution I removed the tape and let the clamps on for a period of 24 hours.


The loose parts were all joined together without any trouble.

Now we need to built a Dowel for the reinforcement.

End of part 3