Tapping Threads in Wooden Pens

[BRobbins629]

Not wanting to limit the customization of tubeless pens to plastics and readily tap-able materials, I came up with a way to use the tap and die sets for wooden pens. As wood will generally not hold the types of threads we are cutting, I made plastic inserts that would function as tubes and a threading medium. There can be many variants of this technique but here's one where I incorporated a PR insert as the centerband along with a silver accent in olive wood burl. The 12mm tap takes a 7/16 hole, so the o.d. of the tenon on the insert is 1/2". Keeping everything round and drilling on the lathe helps center things and there is still plenty of wood on the outside to taper the cap if desired.

 

[alamocdc]

Looks like a very workable technique, Bruce. Thanks for sharing!

 

[thewishman]

Nice idea, much lighter than the brass I was stuck considering. Thank you for sharing - it opens up a lot of possibilities.

That sure is gorgeous wood.

Chris

 

[ldb2000]

I've been playing with the same idea but with tru-stone as the core .
I turn the core down to 1/2" then drill a 1/2" hole in the wood and glue it on and turn to final size , should have some pics soon....I hope

 

[GoodTurns]

I like the idea, Butch. using the tru-stone opens up a ton of possibilities for combos. Look forward to the pictures.

 

[bitshird]

Bruce, black Delrin would to me seem like a better alternative than Polyester resin, it's not as brittle and threads very smoothly, it's readily available in a variety of sizes.

 

[Texatdurango]

Ken, I see a problem using delrin. True, it threads like a dream but you can't glue it to the blank so must rely on a pretty snug "press fit". Withoug a brass tube to give strength to the blank, a press fit might crack the blank.

I have some white delrin and tried making some center pieces and finding a glue to adhere them to the blank was a problem. I tried one pen using a short brass tube just enough to cover the delrin but it was more hassle than it was worth.

I've got one that looks nice but you can spin the delrin band on the blank.

I'm open to ideas.

 

[BRobbins629]

The overall best material I have found for threading it ebonite. A little pricey, but I have yet to lose one due to cracking. It threads nicely, is very forgiving and compatible with CA, epoxy or urethane glues. Agree with Tex on Delrin - the reason we like to use it for bushings for finishing is that CA doesn't stick to it.

 

[jcollazo]

Try using Polycarbonate rod. It's density makes it easy to thread and it's also compatible with CA and epoxy. It's available at McMaster-Carr and other plastic vendors.

 

[redfishsc]

Originally posted by Texatdurango

Ken, I see a problem using delrin. True, it threads like a dream but you can't glue it to the blank so must rely on a pretty snug "press fit". Withoug a brass tube to give strength to the blank, a press fit might crack the blank.

I have some white delrin and tried making some center pieces and finding a glue to adhere them to the blank was a problem. I tried one pen using a short brass tube just enough to cover the delrin but it was more hassle than it was worth.

I've got one that looks nice but you can spin the delrin band on the blank.

I'm open to ideas.

George, have you tried the products made by "Weld-on"? I don't know of any claims they make regarding delrin, but supposedly these two-component epoxies actually melt into the plastic substrate as it kicks over. I have a friend who used it at a place that made fiberglass steeples, and one summer his S-10 truck mirrors fell off (were glued on by GM [B)])-- he used the Weld-on and they have held steady for about 3 years now.


Whether or not the stuff would melt into delrin is a different story. I'm sure the have techs that could answer your question.

http://www.ipscorp.com/industrial/index.shtml

 

[scubaman]

How about just cutting some EXTERNAL grooves into a delrin sleeve and using epoxy to fill the grooves and provide a mechanical bond? The first version of the Berea El Grande cetner coupling used smooth sleeves and a smooth delrin part glued in. It did not hold. They changed the design to add a mechanical component to the fit - I think the metal is grooved in their case. I wonder if a slide fit with epoxy filling the space and some cut grooves would add enough mechanical strength

 

[its_virgil]

Ebonite does thread well but it can be hard on the tap/die...because of the high sulphur content I think. Berea's black acrylic acetate threads nicely. I've not made a pen yet, but I'm practicing threading different materials. Great idea Bruce.
Do a good turn daily!
Don

Originally posted by BRobbins629

The overall best material I have found for threading it ebonite.

 

[ldb2000]

I made a pen from the acrylic that WPP sells (I think it's Acetate...smells like melting film) and if it's the same stuff as Don is talking about it does thread real nice and clean .

 

[BRobbins629]

Originally posted by its_virgil

Ebonite does thread well but it can be hard on the tap/die...because of the high sulphur content I think. Berea's black acrylic acetate threads nicely. I've not made a pen yet, but I'm practicing threading different materials. Great idea Bruce.
Do a good turn daily!
Don

Originally posted by BRobbins629

The overall best material I have found for threading it ebonite.

Don - your right about the sulfur being somewhat corrosive particulary with some metals, but its not something that happens instantly and if you clean the tools and oil them, it shouldn't be a problem. Wouldn't be much different than using a skew to turn an ebonite pen. I've been threading ebonite for several months and the tools still look bright. I have seen where ebonite can tarnish silver very rapidly. Had a silver band in an ebonite pen and it tarnished overnight. That's why I used PR for the one in this thread.

 

[jcgolov]

There has been so many ideas shared that makes my idea about moulding a little bit naive.
I love the idea of a rod that is glued to the wood inside the barrel. This makes so much sense but for known reasons I have been shying away from. After reading your replies, I am going to go systematic on the idea; now I read so many ways to do it.
Many thanks for sharing... The calliper and I are going to become good friends!