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I'm working on a pipe with a very thick stem and when I went to bend the stem the epoxy holding the Derlin tenon got too hot and the tenon came loose.

Does anyone have a trick for avoiding this situation?

Thanks,

Todd

Are you using a hot air gun? If so, wear a leather glove on your pipe holding hand as well as the stem-touching one.

Grab the pipe AT the stem/shank junction before starting to heat the stem, covering it, and keep it there. Doing so will both shield the tenon area from the heat blast, and keep the face of stem & shank aligned/touching when bending pressure is applied.

put a wet pipe cleaner in the stem at the tenon, this will act as a heat sink.

I ran into this a while ago. Biggest takeaway was that it prompted me to reevaluate how I score the delrin before I glue it up.

Those are good suggestions. Thank you.

@Ratimus, how do you score the Delrin?

Todd

Use a heat resistant glue such as JB Weld.

A similar problem can occur with standard ebonite tenons that can get bent with excess heat. I put a stainless reinforcement in every tapered stem over 20mm thick, that keeps the tenon straight and prevents from messing up the stem/shank face allignment.

I use the same Dremel bit as for cutting slots. I do a few pretty deep scores on one side by going straight in with the bit instead of following the circumference. I make this series of grooves grooves at twelve, eight, and for o'clock so the cross section of the tenon in the grooved areas looks like a triangle. Then I go back and do some grooves parallel to the tenon to the depth of the flat spots I have created. Essentially I turn the tenon into a triangle that has nubs extending to the original radius.

Before I do that, though, I pre drill the tenons with a 1/16 hole so that air and excess epoxy have an outlet when I glue them. That ensures I don't get voids and that the tenon can go the full depth of its socket. Before I started doing this, I've had tenons that popped all the way out before I could clamp them, and I've also shattered acrylics by trying to press the tenon all the way into its socket.

I also use a tiny ball shaped Dremel bit to put some dimples on the inside of the socket of the stem, just to give the epoxy a little extra mechanical hold on the stem.

I don't think you should be using epoxy to glue delrin. There are special glues that are formulated to adhere to teflon/delrin.
Also if we are talking about temperature issues it doesn't really matter how much you score the tenon and mortise- if you liquify the epoxy by heating it will give regardless of the grooves, the glue has to be solid to hold the tenon in place.

Integral tenon.

Threads.

Giraffes.

Giraffe.


I mean, I don't even know how you'd use two.

I think you might tick off the giraffe if you start heating it with a heat gun. If nothing else, you'd probably give PETA a new cause...

Sasquatch wrote:Giraffe.

I mean, I don't even know how you'd use two.

You can use them to make more. Then you have a lifetime supply.

This stainless reinforcement sounds interesting, Wojtek.

It's very important to do a stainless steel reinforcement on your giraffes, since that long skinny neck combined with the scorching heat of the Savanna can lead to disastrous results.

Here we are laughing about Giraffes while George lies paralyzed in a pool of vomit. He was trying to type "Help me".

Wow, I ask a simple question and suddenly we are talking about giraffe vomit. I love this forum!

Todd

By the way, I think I will give JB Weld a try. Thanks for that.

Sasquatch wrote:Here we are laughing about Giraffes while George lies paralyzed in a pool of vomit. He was trying to type "Help me".

Maybe next time he'll think twice before attempting to reinforce his own neck with a stainless tenon. #dyac

It’s taken me a long time to get there from where I could touch M. Sasquatch. Now I got a card to play –- you may look into my non-profit, ATWA, and give the man what you think he’s got coming for Air, Trees, Water, and you. Or I will pay him what you think he got coming – the music has make Sasquatch into Abraxas Devil, and I’m SURE you would want some of what I got from what I got. It’s a fallout balance. Beyond good and bad, right, wrong. What you don’t do is what I will do – what you did a sing-along, and let it roll and said how you saved me a lot of steps – I don’t need, it’s not a need or a want. Couped – coup. Ghost dancers slay together and you’re just in my grave Sunstroker Corona-coronas-coronae – you seen me from under with it all standing on me. That’s 2 dump trucks – doing the same as CMF 000007.