Problem with stems on bamboo

[Charl]

I've lately had 2 bamboo-shanked pipes where seperate customers complained about the stems getting slightly "loose" on the s/steel tenon, whenever the pipes are smoked. Anybody else have had similar problems somewhere? Anybody with ideas?

[Tyler]

We need more information. What components and construction method did you use?

[andrew]

I don't know of anyone else that has done this, but I've been using t-88 epoxy and delrin. So far it has worked great. I'm also interested to see what others are doing.

[Charl]

I normally have a s/steel tenon on the stem side of the bamboo, and a mortise into the stem itself. Apparently when the pipe is hot after smoking, the stem gets "slippery" around the stainless steel. Might be the fact that my mortise into the stempart is not tight enough? Or the normally short stem on a bamboo pipe, coupled with having the mortise into the stem and not like on a normal stem, does not take bending well?

[oklahoma red]

No expert here but the materials are vastly dis-similar. Perhaps the heat is causing the wood to expand just enough to cause a "loss of grip" on the stainless tubing.
The expansion rate of the tubing is surely way below that of the wood. I've never messed with bamboo yet. I'm still working on grape vines

[archaggelosmichail]

I had this problem several times.
Tenon hole expands cause of the heat and the contact with much harder material(stainless steel).

I fixed the problem by inserting the back side of a 4mm drill in the stainless steel(my tube has 4mm ins.diam.) and preasure it in a vice so the outside diam of tenon becomes a bit of oval.

[Mike Messer]

You can put a coat of nitrocellulose lacquer on the steel tenon to enlarge it a bit. It dries very hard and quickly. Then sand it smooth, and polish it. Try the fit. Add another coat if necessary, or sand more if the fit is too tight.

This also works for ordinary wood mortise, ebonite tenon stem fiitting, if loose, only, in this case the nitrocellulose is applied to the side wall of the wood mortise. It also tends to stabilize the mortise, some, by protecting it from humidity.

[andrew]

Or you could use a delrin tenon and kiss all this fun you've been having with steel goodbye.

I'm telling ya, it works great.

Does anyone have a good reason for using steel over delrin?

Strength isn't really a factor since both are stonger than the components they are joined to.

I'm sure there is some history and other logical reasons for using steel, but I'm new so please slap me around if I'm spouting nonsense (or if you feel like it, it's been one of those days).

[Tyler]

Or you could use a delrin tenon and kiss all this fun you've been having with steel goodbye.

I'm telling ya, it works great.

Does anyone have a good reason for using steel over delrin?

Strength isn't really a factor since both are stonger than the components they are joined to.

I'm sure there is some history and other logical reasons for using steel, but I'm new so please slap me around if I'm spouting nonsense (or if you feel like it, it's been one of those days).

The diameter of some of the bamboo that is used is too small for a Delrin tenon. No problem doing even an integral tenon if the bamboo is big enough. There is nothing inherently wrong with Delrin though.

[Tyler]

I normally have a s/steel tenon on the stem side of the bamboo, and a mortise into the stem itself. Apparently when the pipe is hot after smoking, the stem gets "slippery" around the stainless steel. Might be the fact that my mortise into the stempart is not tight enough? Or the normally short stem on a bamboo pipe, coupled with having the mortise into the stem and not like on a normal stem, does not take bending well?

I have never done it that way, but I suspect Your problem is why the majority of bamboos I've seen do the tenon the other way around. Glue the tube into the stem, and have the bamboo be the mortise. Of course, you'll want to reinforce the bamboo some way, but I suspect you would with it your way too.

[andrew]

Or you could use a delrin tenon and kiss all this fun you've been having with steel goodbye.

I'm telling ya, it works great.

Does anyone have a good reason for using steel over delrin?

Strength isn't really a factor since both are stonger than the components they are joined to.

I'm sure there is some history and other logical reasons for using steel, but I'm new so please slap me around if I'm spouting nonsense (or if you feel like it, it's been one of those days).

The diameter of some of the bamboo that is used is too small for a Delrin tenon. No problem doing even an integral tenon if the bamboo is big enough. There is nothing inherently wrong with Delrin though.

The diameter issue could seriously put a cramp in things...

[Charl]

I have never done it that way, but I suspect Your problem is why the majority of bamboos I've seen do the tenon the other way around. Glue the tube into the stem, and have the bamboo be the mortise. Of course, you'll want to reinforce the bamboo some way, but I suspect you would with it your way too.

What do you do on the bamboo side then? Delrin? Or would just a vulcanite or acrylic spacer work?

[Tyler]

I have never done it that way, but I suspect Your problem is why the majority of bamboos I've seen do the tenon the other way around. Glue the tube into the stem, and have the bamboo be the mortise. Of course, you'll want to reinforce the bamboo some way, but I suspect you would with it your way too.

What do you do on the bamboo side then? Delrin? Or would just a vulcanite or acrylic spacer work?

The most ommon way I've seen is to turn a small tenon on the bamboo and glue a small vulcanite ring on the tenon. The ring reinforces the bamboo. Another way is to drill a bigger mortise in the bamboo and glue delrin into that which is drilled out to the tube size. When I do that I leave the delrin a little long and glue a ring of vulcanite on that just for transition purposes.

Hope that's clear enough.

Tyler

[wdteipen]

Another way to do it is to make the tenon/sleeve that inserts into the bamboo and the ring integral. This is how I've been doing it. I turn a 1/4" tenon on a piece of ebonite to the depth of the 1/4" mortise in the bamboo and face flush on the ebonite ring to get a good and tight fit against the bamboo. Once I get the fit how I want it I drill 3/8" (or the diameter of the SS tube you're using) in the ebonite and use a parting tool to cut the stem end of the ring the width that I want. I use a special tool to flush the stem end of the ring. Another option would be to turn the 1/4" tenon then chuck the tenon end and drill and face from the stem side. Either way seems just as quick to me.

[Tyler]

Another way to do it is to make the tenon/sleeve that inserts into the bamboo and the ring integral. This is how I've been doing it. I turn a 1/4" tenon on a piece of ebonite to the depth of the 1/4" mortise in the bamboo and face flush on the ebonite ring to get a good and tight fit against the bamboo. Once I get the fit how I want it I drill 3/8" (or the diameter of the SS tube you're using) in the ebonite and use a parting tool to cut the stem end of the ring the width that I want. I use a special tool to flush the stem end of the ring. Another option would be to turn the 1/4" tenon then chuck the tenon end and drill and face from the stem side. Either way seems just as quick to me.

Good idea. I'm going to have to give one of these variations a try.

[Charl]

Thanks for all the ideas and help guys. Will give one of them a try with the next one!