Replies

1. 
   quinbychris | Apr 22, 2003 06:46pm | #1

   Two thoughts:  1) Are you sure that the glue is distributed over the entire brass tube?  If not, you might get some uneven pressure.  2) Are you sure you're not cracking the wood while you turn it?  I've split a couple blanks while cutting too aggressively.  A hairline split might expand as the wood contracts.

2. 
   WorkshopJon | Apr 22, 2003 08:24pm | #2

   I have zero experience making pens, just so you know, but I see you said you are using super glue in their construction. I have used the super, super thin variant of this to repair cracks in wood countless times. Quite successfully I might add.
   The really thin stuff has the viscosity of lacquer thinner. Why don't you try treating the entire pen with it, almost like a finish. It will bind the wood fibers together quite well, and the capillary action will run throughout the entire piece of wood you are working with.

   Jon

3. 
   steves | Apr 22, 2003 10:23pm | #3

   I've made over a hundred pens and occasionally (i.e. ~5%) have cracks that develop after the pen is assembled. Most cracks that I've had have occurred when press fitting the parts in the tubes; the parts get cock-eyed creating excessive stress on the tube cracking the wood.

   There are times when the wood cracks after assembly which can be days or months afterwards. It could be a question of moiture content differential between the wood and your local area. I once used a blank of tansmanian rose myrtle burl that had not dried enough. The result was the blank actually shrank in length and cracks appeared.

   Make sure your press fit parts do not move after installation. Also pay attention to the wall thickness you have after turning. You may want to have a slight camber or thicken up the ends so they are slightly larger than the press fit parts are to reduce radial stresses.