pipemakersforum.com

I caught a thread here and also saw on the interwebs where some carvers were were using delrin even though they had the tooling to just turn the rod stock and make a tenon integral to the rod. Is this to add some flexibility as well as strength to the tenon? I initially only thought this to be a way of salvaging a failed stem but now I'm reconsidering my ideas.

I frequently use Delrin for strength and flexibility, especially when doing a Canadian or Lovat when I do a 1/4” tenon. Part of my reasoning is that in addition to the above, I can finish and polish the stem face more easily prior to doing the tenon.
It’s about the same in terms of work.
I am not certain how the buying public views a Delrin tenon, but that’s up to them.
DocAitch

advantages of delrin are the dimensional stability (i.e. all your tenons are EXACTLY the same diameter, even when temperatures change a bit) so it can actually be quicker and easier to do. Plus it's stronger than acrylic or ebonite and it's self lubricating.

Downside is the whole drilling a hole, roughing the surface, glueing it, ...

I use delrin sometimes, but there are two downsides that keep me using integral tenons most of the time.

1. Delrin tenons have to be glued/epoxied in place and unless you're making a good mechanical connection, it can fail.
2. Delrin tenons limit the flexibility of where you can and can't put a saddle.

Aside from that, it's just a preference.

I almost always use a delrin tenon. Several reasons:

Polyester is not suitable for integral tenons, at least not small ones.
I use the same size tenon for just about all my pipes. I like the consistency.
I prefer a smaller size which would be weak as an integral.
I find it faster and easier.
I can interchange stem blanks easily between pipes, great if I mess up a pipe or a stem.

Thanks everyone.. great and insightful feedback. I can see reasons for doing it and not doing it now.

I'm really liking the consistency of using delrin at this point even though i have the tooling for the integral tenons. Although I learned my lesson quickly on a saddle bit that I didn't account for the delrin rod in.

A quick tap/die with the mortise and tenon before gluing is just as quick as filing and I get a strong joint.

Bluesytone wrote:I'm really liking the consistency of using delrin at this point even though i have the tooling for the integral tenons. Although I learned my lesson quickly on a saddle bit that I didn't account for the delrin rod in.

A quick tap/die with the mortise and tenon before gluing is just as quick as filing and I get a strong joint.

Does it stay dead straight? Are you doing this threading while everything is on the lathe? Not a bad idea really.

Sasquatch wrote:

Bluesytone wrote:I'm really liking the consistency of using delrin at this point even though i have the tooling for the integral tenons. Although I learned my lesson quickly on a saddle bit that I didn't account for the delrin rod in.

A quick tap/die with the mortise and tenon before gluing is just as quick as filing and I get a strong joint.

Does it stay dead straight? Are you doing this threading while everything is on the lathe? Not a bad idea really.

Yes, and yes... just leave the rod stock in your jaws and chuck up the tapping bit and use your quill to advance the bit slowing while turning the jaws by hand to get a straight shot in. Once I've done that, You can do the opposite with the die and the tenon. I clean both ends off and apply epoxy to both sides and use a small dead blow mallet to drive the tenon into the mortise util it bottoms out. I don't screw it in. You wind up with interlocking threads. I drill the tenon before doing this so that any residual epoxy has a place to go and come up a little in the airway hole when I drive the two together. Once the glue sets up I can finish drilling, and of course drilling the rest of the draft hole cleans out any residual glue in the tenon. I'm sure there are a hundred better ways to do it but this is working great and a lot more solid then filing criss-cross patterns or something on the tenon.

Threading the tenon is an excellent idea. The thread is the main mechanical fasting for my tenons, the glue is there mostly to seal any gaps and partly to stop the tenon unscrewing.