A Question for the Pen Turners

[Tom Albrecht]

In my weekly volunteer position I am working with 8th graders and we are currently making fountain pens for the 4th graders. The kits we are using have a long tube for the barrels and a short tube for the nibs. I had two kids working at their machines and I think we lost about half of the long barrels as they suddenly cracked off and the wood came off the tubes. At first I suspected that the kids that had glued the tubes with the epoxy didn't do a thorough job, then as I inspected more of the broken pieces some of them looked thoroughly coated.

My first question is: Should we have used CA glue?

Second question: Is it possible that too much tail stock pressure could cause it?

BTW, we are using a variety of wood species and there was no consistency as to the type.

 

[Gary Beasley]

Did you rough the metal of the tubes before gluing? Epoxy is usually pretty good at holding on, only thing that I can think of is oily woods or oily tubes.

 

[Tom Albrecht]

Did you rough the metal of the tubes before gluing? Epoxy is usually pretty good at holding on, only thing that I can think of is oily woods or oily tubes.

Yep, all the tubes were roughed.
Thanks

 

[Randy Heinemann]

I had this problem with several pens I turned. I don't know for sure what the real cause was, but I finally started turning only 1/2 of the pen at a time rather than mounting both pieces on the mandrel at the same time. It seems as if the blank toward the tailstock had just slightly more vibration than the blank on the headstock end and that this extra vibration may have been causing the splitting and breaking off of pieces of the blank.I can't tell for sure whether this was the cause but, since I've turned the parts of the pen one at a time, I have not had any further losses.

As for CA glue, that's what I use even though it appears that epoxy is recommended over CA glue.

 

[John Torchick]

I use CA exclusively for a finish on wood. I now turn one piece at a time so keep the mandrel from flexing too much. When I turned two pieces, I put a piece of masking tape that matched the pieces and their OAL.

 

[Richard Coers]

Was there any wood fiber left on the epoxy? I would look at the hole in the blank. Dull drill bits would burnish the wood, maybe even glaze or burn it. Too fast of speed on the drill press won't help. Another thing to watch is too snug of fit on the brass and wiping most of the epoxy off. I used epoxy exclusively after sticking a couple of tubes when the CA kicked too fast. I would insert the tube with a twisting motion all the way through to distribute the epoxy.

 

[Tom Albrecht]

Was there any wood fiber left on the epoxy? I would look at the hole in the blank. Dull drill bits would burnish the wood, maybe even glaze or burn it. Too fast of speed on the drill press won't help. Another thing to watch is too snug of fit on the brass and wiping most of the epoxy off. I used epoxy exclusively after sticking a couple of tubes when the CA kicked too fast. I would insert the tube with a twisting motion all the way through to distribute the epoxy.

Thanks for the input. Unfortunately, I was not hovering and watching as the gluing team did their job (not going to happen next time).