A brief procedure on the use of delrin tenons

[caskwith]

Personally even thought i have the tooling to make integral tenons, and do make them every now and again. I still prefer delrin. Its a consistent material, makes for a nice fit with little danger of snapping off and its much more resilient.

[GBMorris]

Well, the preferred material is ebonite - as in an integral tenon made of the same material as the rest of your stem.

However, if you do not have the tooling to cut integral tenons, delrin is a great way to make professional looking tenons that fit every damn time without fuss.

I see! But Why delrin as opposed to, say, some other type of plastic (even ebonite itself), metal, or even wood? Just because it's easy to work with and comes in the right size?

Thanks,
Greg

[KurtHuhn]

Aside from being consistent in size and quality, it also has self-lubricating qualities that provide a good feel when inserting the tenon into the mortis. It's also easy to work with while being an incredibly durable material.

[PipesByDesign]

I recently purchased delrin from onlinemetals.com and the 5/16 bit I've got is a tad too small. Got a recommendation for which bit manufacturer fits that delrin so I don't have to buy a bunch to figure it out?

Thanks.

[oklahoma red]

The large industrial/machine shop supply houses such as MSC, Travers etc. sell what are known as chucking reamers. These are ground to very close tolerances and can be had at nominal size or very slightly under size. Drill the mortise with a 19/64 (.296) bit then ream it and a 5/16 Delrin tenon will fit like a glove. Such reamers are relatively inexpensive. You may want to regrind the tip as these reamers have a small chamfer on the end that will leave a little undersize spot at the bottom of the mortise and it will prevent the tenon from bottoming out.
Chas.

[KurtHuhn]

On the subject of bits...

If you want to reduce the number of bits you have to buy to check for fit and function, always opt for uncoated, HSS, short length drill bits. These tend to run much more consistently in size.

Also, don't lose the bit you finally find, and don't use it on anything else. I should remain dedicated to drilling mortises in briar.

[d_mc]

LocTite sells this stuff:
http://www.loctiteproducts.com/p/13/7/e ... Bonder.htm

It sets up in 7 minutes or so (longer for a full cure) and is designed for plastics. I stumbled on it by accident while looking for something else in the hardware store, and gave it a try. I won't use anything else now - it's damn near impossible to break the bond via mechanical means, and heating the stem hot enough to break the epoxy's bond would mean bad things overall for the pipe.

Sorry to go too far into minutia. . .but I can't find this "Plastic Bonder" epoxy available anywhere?

The same company now sells a "Plastic" epoxy (http://www.homedepot.com/h_d1/N-5yc1v/R ... ogId=10053).
Is this the same stuff?

I really, really hope it is. Because I spent the last two weeks over-heating and dismantling all the "Heavy Duty" Loctite epoxied stems (Acrylic, with Delrin tenons) on my unsold pipes. Then I re-scored and re-glued with the Plastic Epoxy. All that just so I could be 100% sure one of my bonds couldn't loosen if someone overheated a pipe and removed the stem while hot.
. . .FYI, I destroyed at least half the stems/tenons/inlays during this process. And had to remake them. It sucked.

Really hoping I didn't just replace inappropriate (Heavy Duty) epoxy with something equally inappropriate (Plastic)?
Please tell me this is just Loctite changing names on the same product?

[Sasquatch]

Good heavens man.... any epoxy will do if you score the thing and set up a mechanical bond. It's not like these have to withstand atmospheric re-entry.

[KurtHuhn]

Good heavens man.... any epoxy will do if you score the thing and set up a mechanical bond. It's not like these have to withstand atmospheric re-entry.

Sas, that actually got me to "LOL".

If you need to buy what I use, turn to the Internet:
http://www.thehardwarecity.com/products ... er/6281653

I appreciate the need to perform experiments (you really have no idea), but good grief!

[Massis]

I've been having a go at delrin for the last few weeks.

Unfortunately, the only diameter I could find for now was 6mm (0.23", which is about 15/64" I think) so it's a bit hard drilling a 3.5mm airway through it.

Concerning mortises I have also found that my drill bit is just a fraction too small. I solved this by dedicating a piece of delrin to reaming the mortise. I just chuck it in my drill press and spin it in to the mortise, after which I always have nice fitting tenon.

Might be a silly idea, but it seems to do the trick really good and kind of polishes the inside of the mortise aswell.

[d_mc]

Good heavens man.... any epoxy will do if you score the thing and set up a mechanical bond. It's not like these have to withstand atmospheric re-entry.

Yeah, that's what I used to think, too.
Until I removed a stem early after smoking one of my pipes--the briar had expanded from the heat & moisture, and the "Heavy Duty" epoxy reverted to it's goo-stage. The tenon stuck in the shank, and the stem pulled free with no tenon inside.
This wasn't a recent pipe either. It was at least a couple months old. Way more than enough time for every bit of epoxy inside to fully cure.

That's when I decided "Heavy Duty" wasn't good enough.
Of the 20 or so pipes I re-glued. Maybe 5 really needed it. For those, 15 seconds under a heatgun and I could pull either the tenon, or a stem insert, free.

Perhaps fixing *every* unsold pipe was a little obsessive. But I'm glad I did it.
I had horrible visions of someone buying a pipe, then posting pics of it a month later with the tenon stuck in the shank and the caption "Umm, WTF!".

(btw, thanks for the direct link to Loctite Plastic Bonder, Kurt!)

[Sasquatch]

Well, fair enough, that would freak me out too, but I suspect something was wrong with your original glue. I've used the LePage 5 minute epoxy for many, many glue ups and never had anyone say anything failed, so I tend to under think this end of things. If I found a pipe that came apart as a gooey mess after a couple months, I'd undo my entire stock too, to be honest, but that's really, really weird.

[dgerwin11]

FWIW, when I ordered some Delrin tenons from Tim West, he suggested using (and I hope I spell this right) cyanoacrylate. I have seen it listed as CA glue on some pen turning sites. Right now I am using Loctite Plastic epoxy and it seems to work, but I have not put anything to an extreme test either.

[caskwith]

CA or superglue isn't very good at resisting shear loads and it sets very hard making it brittle.

[dgerwin11]

Maybe I'll just stick with plastic epoxy till I have a problem.

[taharris]

CA or superglue isn't very good at resisting shear loads and it sets very hard making it brittle.

I believe it also softens when heated.

[KurtHuhn]

CA or superglue isn't very good at resisting shear loads and it sets very hard making it brittle.

I believe it also softens when heated.

And is not waterproof once set, in my experience.

[dgerwin11]

But I don't smoke underwater. Sorry Kurt, sometimes my bad self makes me do these things.

[KurtHuhn]

Open up your airway like most pros do - then you can use it like a snorkel.

[PremalChheda]

I have been using the score and epoxy method to attach the delrin tenon to the stem, but I have recently viewed another pipemaker that is threading the connection. He still uses a little epoxy just in case, but it is really a good tight fit and will have little to no chance of popping out. Even if it comes out from turning counter clockwise, it can be put right back in by twisting clockwise.