Cracks down the road

[greenchicken]

This happens to me every now and then and it is very frustrating. A beautiful finished pen will develop crack many months later. It is often happen when I work with Ebony, but it is not limited to that wood.

Attached is a bad picture of my most recent lost.

Any advise would be greatly appreciated.

 

[jttheclockman]

This happens to me every now and then and it is very frustrating. A beautiful finished pen will develop crack many months later. It is often happen when I work with Ebony, but it is not limited to that wood.

Attached is a bad picture of my most recent lost.

Any advise would be greatly appreciated.

Welcome to the world of pen turning. You are not alone. But it has been stated many times here wood moves and will continue due to moisture and climate. Now when I make wood pens I take some precautions and they are as follows. Some may have different methods or just think I am full of it.

I always put a finish on wood pens and it is mainly CA. Now if i want a more subtle shine I just knock it down with micropads of some sort. But As I put the CA on I do make sure that I seal the ends with thin CA before assembly. I incorporate this in my finishing method.

The next precaution I take and I think is an important one is I make sure the tubes are clean of CA and in fact I file them down enough so that the parts are finger pushed tight and I place a small dab of loctite on them. What this does is does not put pressuse on the wood from expanding. This happens when parts are pushed on and if there is abit of CA or misalignment when assembling small cracks can form but may not be noticable. After time the CA starts to crack because it can not move with the wood. Remember when the blank is turned down the ends are so thin with most of these kits. So that is usually the place they crack.

Now certain woods are just more prone to crack. It has been mentioned here many times about different woods. Ebony is one of them. Good luck.

 

[Sylvanite]

Some woods move a lot with temperature change. That's why I don't use Katalox on pens any more. When segmenting, I try to avoid woods with dissimilar expansion rates and I try to keep the pieces' grain aligned. That way, at least they expand and contract in the same direction.

Otherwise, I tell my customers not to leave their pens in their cars.

Regards,
Eric

 

[Jgrden]

TRUST ME, EBONY IS THE LEADER IN CRACKING, especially if it is in the sun. The other alternative is how thin the piece is and the heat generated with working with "green" wood.
My .02 cents.

 

[greenchicken]

Thanks guys, some valuable information in there!

But this also leads me to another question. WHY SO DAMN THIN!!!! When I moved up from Slimlines I was surprised that the kits require the wood to be turned so thin. Some of these large pens could easily double, even triple, the thickness if they wanted too.

I would be interested to know why?

 

[1080Wayne]

Part of the answer might be to keep the pen weight down .

 

[darrin1200]

This goes back to your initial question about why your pen cracked.

Wood moves. While it may not seem like much, the difference between 1/16th and 1/8th when it comes to wood movement. When I was learning to do veneer work, it was explained, through demonstration, that if I used 1/8" pieces for my veneer I would have to leave expansion joints.

I don't know the numbers, but it almost feels like the wood moves exponentialy with its size.

So if you had a tube glued in a pen with 1/8" walls, it would most likely crack or separate from the tube.

Just my 2¢

 

[Dale Lynch]

Was looking my pens over the other day and found 2 of my tru-stone retros did that.Gonna have to strip the barrels and try again.

 

[Chris Drysdale]

You mentioned being disappointed with ebony cracking, it is most likely Queen ebony from Samoa in the Pacific, I have experienced my ebony from this source cracking this summer. Mind you we had record heat.
Like to hear where your ebony source is from.
Regards
Chris