Last weekend I went up to John Crosby's house and he gratiously spent time teaching me to do stem inlays. In the process I ended up with a stem with a nice zebrawood inlay to use on pipe #6. This weekend I was working on the pipe. I just about finished when I realized that I had not drilled out the stem at all - it was just a premolded stem with its standard sized hole. I put my tapered bit in my drill and tried drilling it out slowly...
...and the stem cracked!
After composing myself, I picked up another stem - and this time I decided to drill it out first before attempting another inlay myself. And that one cracked too!
What am I doing wrong? For those of you using premolded stems, are you drilling them out by hand? What kind of bit? I swear I have used this before, but now I am starting to doubt myself.
You didn't state the material that the stems were made from, but if they are acrylic, it sounds as if they are not cast acrylic. I forget the other type, but it is much more brittle than cast acrylic, and is not very good for machining. This is just a guess on my part.
Also, maybe use some cutting fluid on the drill bit. Cutting fluid keeps it from heating up as much. A good brand is TruEdge. It is FDA approved for using in food processing plants. Also, what I do is drill a little and let everything cool down, then drill a little more. The stem heats up quickly with a drill bit spinning in the middle, no matter how slow you go.
I use a 5/32" tapered drill bit, set the lathe at 500RPM, and slowly advance the stem. I do it all by hand - no mechanical advance or holders. I also remove the stem and clear the vulcanite dust every 1/4" or so. If you don't clear the vulcanite dust, you trap heat in there, which can cause the stem to crack. Also, the trapped dust will expand, increasing friction and pressure inside the stem, which can also cause the stem to crack.
That's not to say that I'm an expert. I've grenaded a few myself by not paying atention and advancing the stem to quickly on the bit.
Some molded factory stems are just crappy stems, and made of really crappy material and with poor engineering. This could also be a contributing factor to their self destruction.
Thanks for the replies. This one was especially painful due to all the inlay work. When you do inlays, do you do the drilling beforehand or afterward? I'm tempted to do all the drilling first next time in case I kill another one. Would that make it any more difficult to do the inlay work? Doesn't seem like it.
I always end up drilling a little after the stem inlays, just due to the way that I create the inlay. However the stem is typically pretty close to final bore - all I tend to do after the inlay is drill out any epoxy that's left and clean up the bore near the button.
Well, tonight I finished a new stem for pipe #6. I HAD a nice saddle stem with a zebrawood inlay that John assembled while he was showing me the process last weekend. But I killed it (cracked it pretty badly) drilling it out, so I had to start over. I grabbed a taper stem that I munged up turning the tenon, but the tenon was still wide, so I decided to try and reclaim it since I killed the inlaid saddle stem and another saddle drilling them out. I took Kurt's advice and drilled the taper stem with my lathe. Then I added an inlay of birdseye maple (did this one myself, so there is some satisfaction there). In my opinion, I like the tapered stem better with the pipe then the saddle, but the zebrawood was more striking than the maple. Live and learn I guess. Thanks for the tip, Kurt!
With molded stems I generaly drill them lager with a taper bit by hand with a standard power drill. You must be carefull not to go too far into the bit as that would cause a crack as well. Also be sure to clear the dust often as Kurt suggested.
Don't feel bad Scott, I have cracked many a stem in my day. Now that I hand make them that doesn't happen, however, now I worry about sanding down too much and hitting the airway :naughty:
Getting the bit thin is one area where I'm constantly in fear of screwing things up. With molded stems, you just never know where that airway is, what shape it is, and ow thin you can go. When I cut a stem from rod, I know exactly where things are - but that doesn't doesn't ease the tension when I get down to making it really thin.
Ben, I put the long-winded version in your PM box in response to your message. Basically I turned a long tenon on a preformed stem and slipped the inlay and a little vulcanite rod slice over it. A pretty basic approach that seems to work pretty well. I bet there would be a lot more room for creativity if I wasn't using preformed stems, though.
I'm sorry, this post will be a bit OT but the subject of this post got me thinking... I wonder if any bells and alarms went off over at the homeland security office when ScoJo posted this...
Probably in a year or so there will be an FBI profiler with a very interesting story to tell when asked how they got started in pipemaking.
Please pardon a question to all:
Are we talking about INLAY as in cutting out material and laying in something else, like in jewelery, or a Dunhill spot - or are we talking about rings of various materials added to the stem or false tenons?:think:
If we are talking about inlaying material I would love to have someone talk about the methods.
Thanx much folks.
-Steve
