Was wondering if anyone has an idea about how long a phenolic
break ferrule should last a customer? Put one on for a customer a couple of months ago and he has called saying
it has blown apart on him. Could this be the material or
possibly workmanship? Thanx for all input. Cribbeecues
It may be the way you installed it. When I started using phenolic for jump break ferrules I was making an inch long, then I would bore 5/16 hole 3/4 inch deep and then thread the bored hole and screw the ferrule on the shaft tenon.
In some cases the material did split, now I was uncertain why, but I suspected that boring the hole weakened the material. During this time other ferrules installed by others were brought to me for repair that were done in similar fashion that had also broken.
So I decided to change the manner that I installed these ferrules. After I experimented for around a year I came up with the following method that I will share with you.
Now all of these ferrules I install are installed in the following manner:
1. I bore a 5/16 hole 1 1/2 inch down the shaft
2. Then I take a 2 1/2 inch piece of round stock canvas phenolic material and turn down 1 1/2 to .310 thousands.
3. Then I notch the length of the turned down section of the phenolic material every 1/16 inch the length of this section so that extra glue is held.
4. Then I cut a small slot the length of the turned down section to allow for glue relief to prevent any hydraulic pressure which could crack the shaft.
5. Then I apply a two part epoxy slide the turned down section into the hole bored in the shaft apply pressure and allow the epoxy to dry, and then turn down the exposed section of phenolic to the shaft diameter round the end and I am finished.
Since I started doing this more than two years ago I have not had a failure of the phenolic or had a shaft crack and I have done this hundreds of times.
Hope this helps