Shank Extension Tenons and Sleeves and Such

[TRS]

I've been reading around and searching for everything I can find on shank extensions, just learning myself up on the subject, and I've got a quick question if someone would be so kind. The most comprehensive thing I can find is Stephen Downie's site, and I like the method he uses; so if one was to let a mortise 1/4" into the shank, then add a 1/2" hardwood extension with the delrin sleeve, would you then need a 3/4" long tenon on your stem? I'm just curious about what would happen if you wanted a really long extension, because you'd have a long sleeve and you'd need the tenon to fill in that space, right? Does this make sense to anyone? Thanks!

[Sasquatch]

You could drill a mortise for the stem tenon in the shank extension. Functionally, the extension should be no different than the rest of the stummel, if that makes sense.

[TRS]

You could drill a mortise for the stem tenon in the shank extension. Functionally, the extension should be no different than the rest of the stummel, if that makes sense.

That makes sense, but that would be using a different method to connect the extension to the briar, right? I was talking about the method of using a delrin sleeve to help hold the extension on, which then accepts the stem's tenon. How do you (if you do) make shank extensions Sasquatch? And thanks!

[kbadkar]

I epoxy/glue the rough extension wood to the rough briar block and then drill and shape as normal.

[TRS]

I epoxy/glue the rough extension wood to the rough briar block and then drill and shape as normal.

Do you sand the faces until they're square or do you partially shape the shank and the extension and then face them off with a particular tool so they sit flush? Thanks!

[kbadkar]

It depends on what you want to do. But the easiest way is when the briar is still a block. I use a chopsaw, 90 degs if it's a straight pipe or at whatever angle if it's bent. The extension is just a block of the desired thickness, then it's already faced for the mortise if you drill at the "right" angle.

[RadDavis]

I epoxy/glue the rough extension wood to the rough briar block and then drill and shape as normal.

Do you sand the faces until they're square or do you partially shape the shank and the extension and then face them off with a particular tool so they sit flush? Thanks!

You need to turn/face both the stummel and the extenxion for a flush it.

Rad

[TRS]

It depends on what you want to do. But the easiest way is when the briar is still a block. I use a chopsaw, 90 degs if it's a straight pipe or at whatever angle if it's bent. The extension is just a block of the desired thickness, then it's already faced for the mortise if you drill at the "right" angle.

Is that to say you just glue them flat together without any kind of tenon or support rod? And it's strong enough? Or are you turning a tenon with a lathe? Thanks again all!

[kbadkar]

Yes, it's strong enough. A good bond is as good as a solid piece of wood. I've made at least 3 pipes that way, one of which is in my regular rotation, and I haven't had a problem with separation and no complaints from the users of the other pipes. I use delrin tenons, for the most part. I like to have the tenon go through the extension, so only briar is in contact with the smoke, not for structural reasons.

I should add that it is a little tricky to drill the mortise perpendicular to the extension face, but you can get it real close. To be sure, you can use a forstner to face the extension for the stem joint before drilling the mortise. Or if you are the confident type, drill the mortise perpendicular to the face first, check stem junction while the block is still chucked in position and if you are just slightly off, you can take a perfectly flat sanding block to the extension face while it's spinning on the chuck. The corners of the extension wood block might get a little rounded over, but that will be removed anyway when shaped. These are wood lathe tricks. Facing life is much easier with a metal lathe.

[TRS]

Outstanding, thanks again for the information; it is greatly appreciated!

[RadDavis]

Yes, it's strong enough. A good bond is as good as a solid piece of wood.

I would recommend turning a tenon of some sort between the block and extension, either on the block or on the extension. Just to add strength and stability to the bond.

Rad

[kbadkar]

I'm not brave enough to argue with Rad. A turned wood tenon should in theory be stronger with the greater bonding surface area.

But a "good bond" between just (well preped) flat surfaces is critical. Clamp well. If its' a bent, on the chopsaw, cut a little parallel corner on the opposite end and use it to clamp that puppy down. The parallel corner also helps for mortise drill alignment (flat against chuck faceplate). Good wood glue has a stong bond, Titebond III has a 4000 psi strength, for example. I don't see the forces of inserting and removing a stem tenon reaching anywhere near that, and that's mostly a shear force which is glue's forte. The extension on my pipe is going on 3 years of serious shop abuse, numerous drops, spilt coffee, long airplane rides, temp and humidity extremes, countless disassemblies and cleanings, etc. I'm sure I could stick the pipe in a vise and hit the tenonless extension with a hammer.

If you are bonding unlike materials (briar shank/ebonite ring/wood extension, for example), then I would recommend a turned tenon. If you are going wood to wood, I don't think the extra work is necessary. But maybe someday, I'll be proven wrong.

[KurtHuhn]

By far the most secure method of putting a shank extension on is to use a tenon, as Rad suggested. It's really quick and simple to do, and even on a wood lathe doesn't take more than a couple minutes to cut the tenon.

Here's a quick Google Sketchup drawing. The shank is on the left, and the extension on the right.


To cut the mortis in the extension material, I use a forstner bit. Then I simply turn the tenon on the shank to fit snugly in the hole. Turning your tenon and getting a square shoulder is easy if you use a parting tool - looks like this. And practice.


I find it's usually best to make the shank extension mortis first. That way you can size the tenon on the briar shank to fit. Just be sure you make the tenon large enough so that the mortis for the stem fits inside it as I've shown above. You can choose to drill the tenon for the stem before fitup, but I usually drill it later to be sure everything lines up and nothing is off-center or out of concentricity.

When everything it fitted and ready to be glued, I typically use a good 5-minute epoxy and slap everything together using the tailstock to provide a bit of clamping power. Then I go get a cup of coffee, find a snack, or do something else in the workshop while the epoxy cures. From there it's drill and shape as normal.

Other woodworkers will also attest that, depending on the wood, you may need to use a better, stronger, structured epoxy. Cocobolo, for instance, is very oily, and will benefit from using something like T-88. Also, prep the oily wood by wiping down the surface to be fastened with alcohol or acetone, so get rid of some of the surface oils.

[Sasquatch]

Oily woods also do fairly well with casein-based glues, the typical "all weather" woodworking glue being an example - greyish glop rather than yellow glop. These also have more significant heat and water resistance than most shop glues. But I would guess that overall epoxy is stronger over the course of time.

[ToddJohnson]

Use a tenon.

TJ

[RadDavis]

Use a tenon.

TJ

seeeeee!!!

I told you.

Rad

[pennsyscot]

You could use a peice of delrin to connect the extention to the stummel. You could create a 5/16" mortise 1/2" deep in 3/8" delrin 3/4" in length and then use a 5/16" delrin rod to create the tenon. Drill a hole clean through your .5" thick extention and a hole .25" deep in the stummel. I think this might be a good way to attach a shank extention if you did not have a lathe to turn a tenon on the shank extension. The delrin tenon would have a nice smooth fit in a delrin sleeve.

[Nick]

I usually just smear a booger on the face and slap it together. My son's boogers are best, but difficult to collect. Dog boogers work well for outdoor applications, i.e. yard pipes. Don't bother messing with eye-boogers, as they suck. And i really don't want to talk about my expirience with dingleberries.

[TRS]

My son's boogers are best, but difficult to collect.

[TimGeorge]

You could use a peice of delrin to connect the extention to the stummel. You could create a 5/16" mortise 1/2" deep in 3/8" delrin 3/4" in length and then use a 5/16" delrin rod to create the tenon. Drill a hole clean through your .5" thick extention and a hole .25" deep in the stummel. I think this might be a good way to attach a shank extention if you did not have a lathe to turn a tenon on the shank extension. The delrin tenon would have a nice smooth fit in a delrin sleeve.

I have been using this method of attaching shank extensions for a while now, and it is also the method outlined on the Downie website. Seems to work well and I do like the way the delrin tenon slips into a delrin sleeve. (Of course, it may be that I am just afraid of snapping off the shank with my non-existent turning skills).