drilling the rod stock(or steam) for delrin what size

jbacon · Post by **jbacon** » Thu Jan 19, 2006 10:14 pm

wondering what size everyone is using to drill the stem for delrin. i drilled a 5/16 hole into the stem for 5/16 tenon and what a fit.squeezed all the epoxy out. wondering if going up a 64th will be better to have the epoxy cure better or just leave it at 5/16 and use less epoxy.

jim

Post by **KurtHuhn** » Thu Jan 19, 2006 10:56 pm

You need to groove the delrin to hold the epoxy, then apply epoxy in the stem, as well as on the delrin - slop it all around, then press the delrin into the stem. Wipe up the excess epoxy with a paper towel or something. I drill a 5/16 hole for 5/16 delrin, and never have a problem. If you drill a larger hole, for your delrin, it likely won't be centered in the hole, or it might be out of perpendicular with the face of the stem.

jbacon · Post by **jbacon** » Thu Jan 19, 2006 11:02 pm

thanks kurt

jim

geigerpipes · Post by **geigerpipes** » Fri Jan 20, 2006 3:08 am

i make the hole in the stem sligtly smaller than the delrin rod... 10 micormometer to be precise i then glue it and press it togheter using a vise that will force the threads into eachother..

Best

Love
www.geigerpipes.com

marks · Post by **marks** » Fri Jan 20, 2006 6:23 am

I do what Kurt does, and in addition I cut two longintudinal grooves into both the delrin and the mortise I drill into the stem (two way hold).

bvartist · Post by **bvartist** » Mon Feb 06, 2006 1:41 pm

Just curious what are the advantages of using delrin for the tenon over turning a tenon out of ebonite? Is delrin considerably stronger than ebonite? I can see a couple possible advantages, such as the tenon would always be the same diameter, are there others as well???

David

Post by **KurtHuhn** » Mon Feb 06, 2006 2:04 pm

I developed that practice based on a couple key things (in my opinion):
a) delrin is stronger, resulting in less (or no) broken tenons
b) the fit is always buttery smooth
c) you can do tenons that way with a wood lathe - a metal lathe isn't necessary
d) you get a consistent tenon size every time, and once you identify a bit that makes exactly the right size hole in the briar, fitment is completely painless

There are drawbacks:
a) if a customer drops a pipe, the tenon wn't break, but the shank might
b) delrin doesn't polish up like vulcanite
c) if you use translucent or clear stem material, you can see the delrin tenon from the outside
d) you have to make sure that youre drilling is consistent and repeatable from pipe to pipe

Some collectors hate to see delrin, some have no opinion, and some love it. Like anything, there are buyers with very strong opinions on the subject. You can never please everyone all the time.

bvartist · Post by **bvartist** » Mon Feb 06, 2006 2:41 pm

Thanks Kurt!

Exactly the reasons I was looking at changing to using delrin!

I use a tenon turning tool to cut the tenons, and I find them extremely exasperating. At least the one I have from Pimo. Kind of like cut, test fit, too large, adjust, cut, test fit, too large, adjust, cut, too large, adjust, cut, TOO SMALL! another stem wasted.

Plus, I like doing trim bands, inlays and I think it would be easier and less time consuming to use the delrin rather than having to turn a long tenon out of ebonite to accomodate the bands and tenon. And I have neither funds nor space to invest in a metal lathe. Once I get or grind a drill bit to match the diameter of the delrin, I should be set, right?

Time to whip out the old credit card and do some online shopping

David

Post by **KurtHuhn** » Mon Feb 06, 2006 3:06 pm

I found that I didn't have too much work to do to ge the right drill bit. For the stem, I use a 5/16" shorty bit that I got from bitsnbores.com. To drill the mortis int eh stummel I use a 5/16" forstner bit I got from Woodcraft. It give a wonderful flat-bottomed mortis. My technique is to only dril one twist of the tailstock at a time before backing out the bit to clear wood chips/dust - probably 1/12" or so. That makes a repeatable hole that's always the same finished size.

Also, do yourself a favor, and drill the airway in the delrin *before* you epoxy it into the stem. trying to drill that after the fact will result in much pulling of hair and the utterance of many colorful metaphors.

jeff · Post by **jeff** » Mon Feb 06, 2006 8:29 pm

Kurt,

I occasionally use delrin tenons and do things a little differently. I prepare the delrin first by facing it, drilling a 1mm pilot hole and cutting deep threads in about 1/4-3/8" of it. Then I chuck up the rod stock. I face that, drill a pilot hole, ream to depth with modified reamer that leaves no shoulder, but a flat bottom. Then I thread the inside of the 5/16" reamed hole with a modified jigsaw blade. Next I put epoxy in the hole and around the delrin. I insert the delrin and the 1mm hole ejects the excess glue and ensures that my tenon is dead bottom in the rod stock. I don't want ever want smoke to touch epoxy. When the epoxy has become rubbery I peel off the excess from around the tenon and wait for it to fully cure. Then when the glue has fully cured I proceed with my normal drilling operations. I find that this method creates both a very strong bond as well as ensures that the airway will have absolutely no epoxy or residue left over inside.

I think, though, that this might be limited to those who can work with a metal lathe due to the facing procedures. Then again, if you have a steady hand I'm sure you can get close.

Best,

Jeff

Nick · Post by **Nick** » Tue Feb 07, 2006 9:17 am

Cool procedure Jeff. Thanks for sharing that.

Can you describe a bit more about what you do with the jig saw blade? I got everything but that.

Post by **KurtHuhn** » Tue Feb 07, 2006 10:13 am

Jeff,

That sounds like an AWESOME procedure. Mind if I steal part of that and it to my own?

For facing I use a precision ground Forstner bit on my wood lathe. While I *can* get a flat face using a combination of cutoff tool and skew chisel, it's faster and more accurate to use the Forstner bit. However, in the not-too-distant future, I'll be grabbing a Jet lathe. I just have to save the scratch for one, then things will be even more accurate and repeatable.

jeff · Post by **jeff** » Tue Feb 07, 2006 10:22 am

KurtHuhn wrote:Jeff,

That sounds like an AWESOME procedure. Mind if I steal part of that and it to my own?

Umm, yes. Sorry, it's my signature and you can't use it without paying royalties.

Help yourself. I wouldn't have shared it unless I felt that you might find the procedure useful.

I had previously used a standard jobber bit to drill the hole in the rod stock, but because I was interested in eliminating a glue line at the face, I found it exceedingly difficult to shape the delrin rod end at the precise angle of the inside face of the vulcanite. So, I started to use a reamer instead and have really enjoyed very positive results. Another option is to use an end mill to drill the vulcanite.

The jigsaw blade isn't really a necessary tool for this procedure, but simply something I had for other steps of my process that was useful for scoring the inside of the drilled hole. The main point is that you should score the inside of the hole to give the glue greater surface area and indentations that provide gripping power. Use whatever you can.

Best,

Jeff

bvartist · Post by **bvartist** » Tue Feb 07, 2006 10:41 am

Thanks Kurt and Jeff for both your procedures. Gives me two ways of doing things that I can adapt to the equipment I have. I haven't yet figured out how I can cut the inside grooves but I'm sure I can come up with something. Just a matter of getting more surface area for the epoxy bond.

I was thinking that using a 5/16 forstner bit to bore the ebonite would make a flat bottomed mortise as well. I had an end mill I used to bore the stummel for the tenon, but can't for the life of me find where I put it.

Another idea would be a spiral router bit.

Thanks guys!

David

LexKY_Pipe · Post by **LexKY_Pipe** » Wed Feb 08, 2006 5:46 pm

The discussion on delrin tenons has been so helpful. You guys are a great help to newer pipe makers. Thanks.

bvartist · Post by **bvartist** » Wed Feb 08, 2006 6:34 pm

I agree!!

Everybody on this site is so helpful. I do a lot of artistic/creative things from painting to building custom fly fishing rods. Trying to find info or someone to help you through problems on anything else is like pulling teeth! 8O Sure makes the journey a lot better.

David

jbacon · Post by **jbacon** » Wed Feb 08, 2006 9:05 pm

yes, yes, yes

thanks to everyone

jeff

can you expand on the modified jigsaw blade, did you grind it down to fit in the mortise you drill in the rod stock

as always thanks everyone for sharing

jim

Post by **KurtHuhn** » Sat Feb 11, 2006 12:12 am

If I was going to do that with a jigsaw blade, I would grind off all the teeth except for one, and then slap it in the toolholder and use it to groove the interior of the mortis.

Best used on a metal lathe, I'm sure.

jeff · Post by **jeff** » Sat Feb 11, 2006 1:43 pm

Really, guys. Being that precise is not important with this specific operation.

The jigsaw blade is relevant only insofar as it is the tool that I have chosen to use. You might choose a needle file or even a little exacto blade. Essentially, you need to get something small enough to fit in the mortise without marring the edge (you don't want any evidence that there is a mortise present and messing up the shoulder is a dead giveaway.) Then you proceed to rough the inside of the mortise to give the glue a surface to grip. So, it doesn't really matter what you use as long as it is sharp and stiff enough to gouge the mortise.

The other thing to consider is how far in you are recessing the delrin. If its too far to fit your tool then it's too far in general. You do not need 1/2" or more of delrin inside the rod. That's excessive and limits the stem designs that you can do. I typically only drill my mortise 1/4" to 3/8" deep for the delrin. I hope that's helpful.

As to the blade that I use, it is just as you imagined. I've ground it down so that it will fit.

Good Luck!

Best,

Jeff

josh_ford · Post by **josh_ford** » Sun Feb 12, 2006 5:32 pm

Where is a good place to get this delrin stuff and what size or whatever should I look for?

Josh