Bamboo

[Briarfox]

Hey guys, I just have a quick question on bamboo. In the past I have ran a long 1/16 bit, by hand, to make the initial hole in a length of bamboo. Then use a 5/32 bit, by hand, to open it up all the way. I'll then drill the 5/16 mortise. My question is:
1) Do you guys ever epoxy in the tenon on the stummel side?
2) Should I insert an aluminum tube through the bamboo? I haven't in the past and it's smoked good but it does seem to gunk up easy.

Thanks,
Chris

[KurtHuhn]

I pretty much always use a tapered 5/32" bit right from the start. The taper helps it be self-guiding. Then I use 5/32" thin-wall stainless steel tube for the tenon. I do not allow epoxy inside the bamboo. I epoxy the face of the bamboo to the shank. The stem side is typically faced with a small bit of acrylic or vulcanite. I also do not line the bamboo with anything.

[kbadkar]

A cool thing about bamboo is that it absorbs moisture, so I've found my bamboo shankers to be among the driest smokers. Running the tube all the way through would delete this property. I do put a dab of epoxy near the tip of the SS shank tenon, rather than in the bamboo drilling, and twist in so the epoxy doesn't push or ooze into the airway. I do the same on the other end when inserting into the stummel. Of course, the epoxy between the shank and stummel faces does most of the "work".

[Briarfox]

As always thanks for the info guys. So on the stem side are you guys going with a standard mortise or with the 5/32 SS tube?

[KurtHuhn]

Stainless steel FTW.

[Briarfox]

Sorry Kurt, one more question. Would it be better with an Inside diameter of 5/32 on the SS tube? And just drill a mortise for the OD of the tube? Or is there no noticeable difference in the airflow with a OD 5/32 and thin wall?

Also I can't seem to find 5/32 tube on the online metals site linked on the wiki, I only see a OD of .1875. Is that your source?

Thanks,

[kbadkar]

Get the 5/32" OD, so you don't have to mess around with odd sized drill bits. There is really no noticeable difference with a slightly smaller ID. Check McMaster-Carr. I think it was called hypodermic tubing?

[KurtHuhn]

Kris has got you headed in the right direction. I use the ~5/32" OD stainless hypodermic tubing. The OD is actually .148, and is designed to fit inside a 5/32" hole. I use the .01" wall thickness stuff. McMaster-Carr item# 89935K258.

The .02" reduction in airway diameter isn't going to negatively affect the flow. Also, drilling a single channel, reduces the chances of human error, and expensive mistakes.

[Alan L]

While we're on the subject, I have some raw bamboo I'm gonna eventually use, but I'm not sure how to finish it. Just buff it up and wax?

[kbadkar]

That's all I do, wax that is. I don't buff with compound, because it seems to fill the pores with the stuff. You might get away with using white diamond, without staining the bamboo. I've heard of others that use shellac as well.

[Briarfox]

Kurt,
Turns out the tube supplier is right around the corner, shipped and recieved in the same day The .148 tubing seems to be a tad small. Do you have that issue? I can see it working on the stummel/bamboo joint because of the epoxy, but do you use the same material for the bamboo/stem junction? Seems like it would be a tad loose. But again a 5/32 isn't always a 5/32.

[Briarfox]

On a side note, any advise for facing off the bamboo? In the past I've used the lathe, which is tricky. I did my last one by hand and I'm having issues getting it to fit flush.

[KurtHuhn]

The .148 tubing seems to be a tad small. Do you have that issue? I can see it working on the stummel/bamboo joint because of the epoxy, but do you use the same material for the bamboo/stem junction? Seems like it would be a tad loose. But again a 5/32 isn't always a 5/32.

I'm reasonably sure that's the size tubing I use. You do need to be sure that you find the right drill bit for the job, and that you don't bugger up the very end while drilling. 5/32" isn't always 5/32", so you need a good bit to be sure the hole is the right size.

If you still can't get it, try the .18" tube. It's a little closer to 3/16" than the other stuff is to 5/32". Just drill the whole thing through 3/16", and don't worry about mortises or anything.

One thing that may help is to use a slice of acrylic or ebonite at the stem end. It will help provide a closer tolerance to the tube, and hold it securely.

And if all else fails, paint the inside of the bamboo at the stem end with shellac, lacquer, clear nail polish, or whatever - you just need to make up a few thousandths with some material so that it holds the steel when inserted.

On a side note, any advise for facing off the bamboo? In the past I've used the lathe, which is tricky. I did my last one by hand and I'm having issues getting it to fit flush.

I used to use the hard disc grinder on the side of one of my belt grinders and face it by hand - but that's very fiddly, takes forever, and can use up a lot of bamboo material tweaking and refitting. What I've done for the last few years is insert the stainless tube into the bamboo (not glued, just a friction fit), mount it on my lathe (stainless tube held in the collet chuck), and use a sharp cutoff tool to face the bamboo perpendicular to the tube. Then I swap the bamboo end over end, and do the same thing for the other side. Takes no time at all, and is 100% accurate. Use a handheld countersink to clean up anything that remains on the end.

[Nick]

Neat trick!

[Briarfox]

Thanks again Kurt. I use that same trick for re facing the shanks (also your suggestion). I just don't think I have a tight enough fit for the lathe. But I'll play with it.

[KurtHuhn]

Just to give credit where it's due, Todd Johnson first suggested this method to me a few years ago. I can take credit for inventing a couple things - but this isn't one of them.

[kbadkar]

Kurt,
Turns out the tube supplier is right around the corner, shipped and recieved in the same day The .148 tubing seems to be a tad small. Do you have that issue? I can see it working on the stummel/bamboo joint because of the epoxy, but do you use the same material for the bamboo/stem junction? Seems like it would be a tad loose. But again a 5/32 isn't always a 5/32.

Something was very strange about all this, because my tubing bought from McMaster fits nice and snug in my 5/32" airhole. I remember ordering the 5/32" OD, but when I looked up under hypodermic tubing, they didn't list this size. I finally managed to dig up my receipt from 2006. They used to have tubing with the OD matching US standard measurements!

Here's the description: Part number 6100K172 - Precision Type 304 SS Welded and Drawn Tubing 5/32" OD, .146" ID, .005" Wall, 12" Length (Same as 6100K171).

In fact, that part number still works and they have it. Look it up and get the right stuff!

[KurtHuhn]

Huh. Look at that. I took a mic to my to my tubing and it does indeed measure out at .1555. And if you search for "stainless steel tubing", you'll find that part number.

Apologies folks - that's a pretty major cockup in advice. Goes to show you - I DON'T know everything. And that it never hurts to fact check.

[Briarfox]

I got the 5/32 tubing in today and it fits great. but I'm stuck with the .148 oh well, thanks again guys

[FredS]

. . . Goes to show you - I DON'T know everything. . .

Better make sure the wife & kids don't see that post Kurt.