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I had the misfortune of dropping one of my pipes the other day and snapped the stem off, clean! In attempting to make the best of a bad situation, I thought this might be an opportunity to try my hand at the repair. I have some black Delrin rod of the appropriate diameter on its way from McMaster-Carr and wanted to double check the order of operations to make sure I understand the process correctly.

1. Remove old tenon from pipe. Done.
2. Set up stem in drillpress, using drill and existing airway as an alignment guide.
3. Drill out stem to diameter of replacement tenon rod. Note depth of cut.
4. Epoxy correct length of replacement rod into stem. Let cure.
5. Drill new airway in replacement tenon using depth of cut from Step 3 to avoid over-drilling.
6. Final fit tenon to mortise.
7. Smoke!

Did I miss anything? Any "tricks of the trade" that might help me do the job right the first time?! Thanks, in advance.....

Mitch

Good suggestions! I agree, alignment of the stem is critical, so I'll be taking special care, there. Your idea of drilling the tenon airway prior to epoxying is a good one, as is using the Vaseline'd drill for alignment and to keep the airway clear - hadn't thought of those! I had seen the drill guage suggestion on another board or thread but since it was you that posted it, ya get credit for that one too!

Many Thanks!

I'd also add that you'll want to cut some grooves into the end of the Delrin that is to be epoxied into the stem. The Delring is very slick, and can fit very tightly into a hole drilled the same diameter as the Delrin. This can lead to too little epoxy between the stem material and the Delrin to hold the slick Delrin with a good bond. The grooves allow some epoxy space so there is plenty there to bond.

Tyler

I've replaced a couple of broken tenons with delrin in stems that were were mostly round. Held the stem in the vice between two pieces of wood drilled to the approx. diameter of the stem.
Any recommendations on how to hold a tapered oval stem in a vice for drilling?

make a jig out of wood - just a v-notch on a flat block will work.


I'd also add that I would leave just a LITTLE play in the delrin/stem glue-up, and possibly put the delrin in, wipe up any mess, and then assemble the pipe - this would assure you of the alignment.

Sasquatch wrote:make a jig out of wood - just a v-notch on a flat block will work.


I'd also add that I would leave just a LITTLE play in the delrin/stem glue-up, and possibly put the delrin in, wipe up any mess, and then assemble the pipe - this would assure you of the alignment.

Thanks Sas. I'll give that a whirl. Wasn't sure if a V notch would work or not. I did drill the hole in the others I've done slightly oversize in order to align the stem.