"A" joint

[qbilder]

So in another thread, there's a little discssion going on about "A" joint adhesives. It's a topic I am immensely interested in, so I figured I'd begin a new thread so to not side track the other.

Here's some pics of a typical "A" joint of mine. I begin with a 3/4" tenon on the back of the forearm, fit the ring on, then shave the tenon on down to 5/8". It's an inch long and fits nicely into a 5/8" bore in the handle. Pretty standard stuff. My question is about the adhesive. What difference would it make if I use a thin viscosioty epoxy, or a thick viscosity epoxy? Or would it even matter? There's conflicting views on viscosity. The tenon fits the bore smoothly with only a couple thou glue room. Note the glue chanels lon/lat on the tenon. The stud is 3.75" long, equally split between handle & forearm.

 

[sileighty_guru]

Same here! I go with or without screws depending on weight but use the same shoulder/groves concept. No issues yet.... but still early in the game for me! I use West just because it is a longer set (no cracks yet from pressure) I cut my first 2 in half and there was no gaps from soak-in. There are times I have used both a threaded tenon with a metal joint screw (weight or repair issues)

 

[Joe Barringer]

Wow - such clean and pretty work on both the above.

 

[Sunchaser]

Wow - such clean and pretty work on both the above.

Yes impressed by the way these both look...excellent example of how to make them with apparent high quality and tolerances. Very clean. Thanks for sharing. Matt D.

 

[JoeyInCali]

So in another thread, there's a little discssion going on about "A" joint adhesives. It's a topic I am immensely interested in, so I figured I'd begin a new thread so to not side track the other.

Here's some pics of a typical "A" joint of mine. I begin with a 3/4" tenon on the back of the forearm, fit the ring on, then shave the tenon on down to 5/8". It's an inch long and fits nicely into a 5/8" bore in the handle. Pretty standard stuff. My question is about the adhesive. What difference would it make if I use a thin viscosioty epoxy, or a thick viscosity epoxy? Or would it even matter? There's conflicting views on viscosity. The tenon fits the bore smoothly with only a couple thou glue room. Note the glue chanels lon/lat on the tenon. The stud is 3.75" long, equally split between handle & forearm.

You can have BOTH in one joinery.:smile:
So, you get the benefit of both config.
Thin penetrates the walls of that handle . AND the bottom .
You'll never have a dry spot.
Thick fills any cavity and any loose thin mix will get pushed out when the thick mix pops at the top.
Try once and you'll probably never look back.

Mock one up with a purpleheart handle . Notoriously prone to buzzing b/c of epoxy resistance and tougher to thread .
Stick in the car and check it week after week.

The thread is not about this
http://i3.photobucket.com/albums/y69/Qbilder/cue construction 10/DSC03944_zpsz8h6cgd5.jpg
but, nice touch on that coco stem going in the ring. And taking away the load from the ring by starting at .750" tenon.

 

[qbilder]

nice touch on that coco stem going in the ring. And taking away the load from the ring by starting at .750" tenon.

Nice of you to notice I wondered if anybody would catch that.

Learned that trick from a Hawaiian cue maker, Dellera, years ago when visiting his shop. He stepped the base of his forearm like that so the base of the points would be locked inside the handle. Then in a conversation with Mike Bender, I was complaining to him that when I used rings in the "A" joint the cue would sometimes develop a buzz. He didn't tell me what to do or even offer any advice. He looked at me like I was an idiot & asked me why I'd ever make rings part of my "A" joint. I am using a core and working with rings rather than points, but the concept is the same. I put two & two together & realized what both men were getting at, even though for completely different reasons. Sometimes the simples, seemingly insignificant things make a world of difference.

 

[qbilder]

Wow - such clean and pretty work on both the above.

Thank you.

 

[qbilder]

Yes impressed by the way these both look...excellent example of how to make them with apparent high quality and tolerances. Very clean. Thanks for sharing. Matt D.

Thank you.

 

[aphelps1]

To address your question on viscosity, here is my take:

Too thick of viscosity and you have the possibility for air pockets or hydraulic blow-out, too thin a viscosity and you risk too much absorption into the wood creating a dry joint. So there is a Cinderella zone for the right viscosity. This is also dependent on temperature, humidity, and the rotation of the earth. don't get me started on barometric pressure or dark matter attraction.

Alan

 

[Mcues]

I've been using T-88 for a very long time, for both Joint Pins and A joint. I do use relief channels on the 3/8 16 rod and also the wood tenon; dry fit everything and use witness marks then I heat the epoxy under my lathe lamp while mixing. If I use rings on the A joint they're done same as shown by Erik above.

I use 206 for cores, don't like the T-88 for that purpose.



Mario

 

[sileighty_guru]

Thanks Joe, and Sunchaser! OCD has benifits

 

[ratcues]

I do not think the viscosity matters as long as the glue is allowed to wick and saturate the faces of all contact points. Apply glue...wait...repeat. When the glue stops wicking, then assemble the cue.

Most guys will slather glue on and screw it together, squeezing the excess glue out. The little glue that is left wicks into the face(s). The may not buzz at first but a change in temp or humidity will cause it to fail, especially in dissimilar woods, ie; maple to cocobolo. Each wood reacts differently to change.

This happens at every point where there is a cross grain face. Joint/shaft collars, ferrules, butt sleeve/cap.

 

[qbilder]

I do not think the viscosity matters as long as the glue is allowed to wick and saturate the faces of all contact points. Apply glue...wait...repeat. When the glue stops wicking, then assemble the cue.

Most guys will slather glue on and screw it together, squeezing the excess glue out. The little glue that is left wicks into the face(s). The may not buzz at first but a change in temp or humidity will cause it to fail, especially in dissimilar woods, ie; maple to cocobolo. Each wood reacts differently to change.

This happens at every point where there is a cross grain face. Joint/shaft collars, ferrules, butt sleeve/cap.

From a guy who has seen a share of failed "A" joints.

 

[dzcues]

Some great info here on epoxies but the construction techniques only apply to forearms without points. Here's one way to achieve something similar with a pointed forearm. Any others?

 

[Murray Tucker]

I don't have any photos handy of the individual pieces but I use the double tenon method these days on cues that get a wrap. Tenon on the forearm, tenon on the handle and a piece of phenolic to join them. 3/8 X 16 aluminum or stainless screw depending on desired weight/balance.

For wrapless then I do pretty much what Eric showed.

 

[JoeyInCali]

I agree with the RAT.

If you thread on a phenolic tube or rod down the A-joint cavity, you will less likely have buzzing problems imo.
They make for stronger female threads as well.
And you reduce end-grain to end-grain contact.

 

[qbilder]

Some great info here on epoxies but the construction techniques only apply to forearms without points. Here's one way to achieve something similar with a pointed forearm. Any others?

Bob, the tenon is on my forearm. When I cut points, they extend past the bottom of the forearm, onto the tenon. The tenon then fits into the handle, thus locking the base of the points inside the handle. I might note as well that the tenon is actually the forearm's core, so that tenon runs from the joint pin thru the forearm and anchors an inch deep into the handle. I core my handles with 16.5" cores to leave room at the back of the handle for a butt sleeve & such. I may also add that the forearm core is 5/8" with a 3/4" step at the base, which butts shoulder to shoulder on the end of the fore. Once the rings are installed & shaved flush, the 3/4" step is then cut down to 5/8". The handle core is 3/4" and the 5/8" core from the fore fits into it with a 1/16" side wall between it and the host wood of the handle. I know a pic would say it much better, but I can't find one.

 

[j2pac]

Wow - such clean and pretty work on both the above.

Amen Joe B. These are really nice examples of clean, top notch work. Bob Dzuricky also comes to mind. Really good stuff. Nice work guys. Now if only your cues were cheaper. Lol.

 

[Mcues]

Some great info here on epoxies but the construction techniques only apply to forearms without points. Here's one way to achieve something similar with a pointed forearm. Any others?

Bob, what's the dimensions of the phenolic shown. Thanks

 

[dzcues]

Bob, the tenon is on my forearm...edited for brevity... I know a pic would say it much better, but I can't find one.

Got it. I've done that on a few cues but the trade off (when using my regular point geometry) is shorter points & a wider gap at the base of the points. Not sure that I want that. Besides, I can make the points only about 1/2" longer due to veneer sheet length.

Bob, what's the dimensions of the phenolic shown. Thanks

5/8" x 2". And sometimes I'll used the phenolic pcs shown in this video: https://www.youtube.com/watch?v=k-8TVamrTtk