Mortise/Tenon problem

hazmat · Post by **hazmat** » Tue Apr 29, 2008 9:48 am

Okay. This is kind of interesting. Several month ago, I began working on a pipe and got a little sidetracked with life. It's been sitting on my workbench and I finally had the time over the weekend to spend some quality time on it. The stem is handmade with a delrin tenon and the whole shebang fit together as it should at the time I drilled it. Nice and snug but not too tight. You guys know how a proper mortise/tenon goes together...it was there.

I noticed no issues with it over the period of time I couldn't actually work on it. Nice fit. All good. So I'm working on it this weekend and doing some final buffing/polishing and I'm noticing the tenon/mortise fit is getting a bit loose. It's not dramatically loose, but just enough that it bothers me and could be construed as poor workmanship. This pipe hasn't gone through any drastic changes in atmosphere. My shop is on the main floor of my apartment and there aren't many fluctuations in that vain. Humidity has been kind of goofy that last several days here in PA, so maybe that's part of it.

In the end, I guess it's not much of a big deal as the pipe won't leave my possession. It was an experiment in shaping and finishing methods from the beginning so I had no high hopes for it outside of learning a thing or two from it. However, I'd like to figure out why the tenon is suddenly a bit loose when it's been fine for several months. Anybody have a similar experience?

kkendall · Post by **kkendall** » Tue Apr 29, 2008 11:51 am

Was the stem left inside the pipe the whole time? Curious indeed? Did you mic the delrin to see if it compressed?

Maybe leave the stem out for a week and see if the delrin goes back to original size?

Frank · Post by **Frank** » Tue Apr 29, 2008 1:11 pm

Try giving it a bit of a heating with a heat gun. It might "relax" a bit, just enough to snug up in the mortise again. This often works for me with loose vulcanite stems. This past weekend it worked for me with 3 different stems. Of course, it might just shrink up even more and then you're buggered.

kkendall · Post by **kkendall** » Tue Apr 29, 2008 1:53 pm

Warming up the tenon may do it. Stem materials have a memory (ever notice how a bent stem will straighten right out when you warm it up?).

hazmat · Post by **hazmat** » Tue Apr 29, 2008 2:53 pm

kkendall wrote:Was the stem left inside the pipe the whole time? Curious indeed? Did you mic the delrin to see if it compressed?

Maybe leave the stem out for a week and see if the delrin goes back to original size?

It was on and off, depending on whether I had time to work on it or not. It's not a flush-fit stem, so leaving it out while working on the stummel's not an issue. I'll do that and see what happens. If it doesn't help, I'll try the heat method and see what's what. Thanks, fellas!