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Tightening tenon fit...

Posted: Tue Jul 05, 2005 2:36 pm
by ScoJo
I find that the tenons on the pipes that I made have been loosening over time - one one pipe I can pull the stem straight off now without twisting (poor testiculo!). How do I fix this, and how do I prevent it in the future? It seems when I am making the pipes, the stem fit is very tight - so much so that I feel I risk breaking off the tenon (which I have done once - followed by cracking the shank in half trying to get the tenon out - ouch!). But later the stem fit is too loose!

:x

Thanks,
Scott

Posted: Tue Jul 05, 2005 4:06 pm
by LexKY_Pipe
When you first fit the tenon, it's better for it to be a little tight. Use some bees wax on it to help it fit. After it's smoked a time or two, then you might need to adjust the size.

If it's a vulcanite tenon, carefully heat the tenon over an open flame. Then carefully press the tenon into something like a vise to compress the tenon. Heat it just enough to make it pliable, not sloppy.

Another thing you could do is buy the stem tightener kit from Pimo. Follow the instructions.

Posted: Tue Jul 05, 2005 7:09 pm
by RadDavis
You can also run an ice pick into the tenon to expand it after heating. For me, this carries less risk of getting the tenon misaligned than pushing it onto a flat surface.

It's the same principle as the Pimo kit, but it only costs about a dollar.

Rad

Posted: Wed Jul 06, 2005 8:44 am
by ToddJohnson
Smoke it.

Todd

Posted: Thu Jul 07, 2005 6:33 am
by marks
ToddJohnson wrote:Smoke it.

Todd
That's always seemed to work for me.

Posted: Thu Jul 07, 2005 2:32 pm
by BDP
Ditto the two messages above!!

Posted: Thu Jul 07, 2005 4:17 pm
by ScoJo
I know that smoking the pipe tightens the fit, but I am concerned that if I give someone a pipe (I am not to the point where I feel I want to sell one yet - the workmanship is not where I want it), that it would look bad if they picked it up to smoke it and the stem came right out accidentally.

And before you say it, I know...you get what you pay for!

:lol:

Posted: Thu Jul 07, 2005 11:11 pm
by sagiter
Well, if you're going to give someone the pipe, tell them of the problem and they'll be careful.

Neil

Posted: Sun Jul 10, 2005 1:47 am
by Tyler
Scott,

I used to be frustrated by this as well. I have not had this problem in quite some time though, and here is what I think has cured it for me.

1. Cutting better tenons. Once I figured out how to get glass smooth tenons straight off the lathe, this problem was almost 100% remedied. I believe this was because the tenon was smooth, AND because it was a VERY consistent diameter over the length of the tenon. This gives the tenon maximum contact with the mortise for maximum friction.

2. Drilling better mortises. This helps for the same reason as above. I give the above more credit because it is harder to do well, IMO. With mortises I have learned that on my equipment it is key to drill the mortise in one smooth stroke. Don't drill and pull the bit out to check out alignment and/or depth, then drill some more. Measure, mark the bit, and trust it. With the slight slop in my lathe I would leave very small ridges each time I pulled the tails stock back to check things, then drilled a little deeper.

Without precise tenons and mortises, they will tend to loosen more easily because only a small area needs to wear down for the friction fit to be lost.