Reinforcing a Wooden Pen Blank

[TonyW]

I've just had to repair a pen set I gave to someone some time ago as the wood had cracked and even split in one place. As best that we can make out it was caused by moisture movement in the wood, as there is a wide range of both temperatures and humidities where they live. I can only assume that the outer surface of the wood, and it's ends moved but the inner surface couldn't because of being glued to the brass tube. I used CA to glue the tubes and cellulose sanding sealer followed by carnuba wax as a finish by the way.

I have been asked to turn some more pens but in Bethlehem olive wood. I have had troubles with olive wood bowls in the past and so am worried that I will have a repeat performance with pens so what would be a better way to treat the wood please, given that olive wood can be naturally oily? Would an elastic glue such as polyurethane be better on the tubes and if so, will it stick to oily wood? Should I seal all of the wood including the ends with such as CA? I really do need some help here please!

TIA

Tony Wells.

 

[stonepecker]

Stablized blanks will do the trick. The juice holds the wood together.
JMHO

 

[TonyL]

I have no idea to what extent this works, but was I instructed to lightly coat the inside of the barrels will thin CA (w/out accelerator). It is easy. and may be more like throwing salt over your shoulder..so I do it.

 

[stonepecker]

I have no idea to what extent this works, but was I instructed to lightly coat the inside of the barrels will thin CA (w/out accelerator). It is easy. and may be more like throwing salt over your shoulder..so I do it.

I have done the same thing Tony. But then I also have had to redrill the whole for the tube to fit. I believe anything you do like this is always a help.
After all, what can it hurt? :biggrin:

 

[TonyL]

I have been lucky without having to re-drill. I just drip enough into the hole and let gravity do the rest.

 

[jttheclockman]

Use epoxy to glue blank to tube. Will move when needed. Seal all ends with thin CA. BOW is a nice wood to work with. If dried properly it will not crack. Who knows about drying because the seller controls that and how many sellers are involved in each blank. Who knows. Good luck.

 

[SteveG]

I have no idea to what extent this works, but was I instructed to lightly coat the inside of the barrels will thin CA (w/out accelerator). It is easy. and may be more like throwing salt over your shoulder..so I do it.

Tony (Both "L" and "W"), it is often beneficial to know and understand the "Why" behind the process. When you turn a pen, the wood that remains is fairly thin. In this case, if you apply the thin CA to the inside of the drilled blank, you are in effect stabilizing the exact portion of the blank that will remain, once you turn the pen. (If you did the same treatment to the outer surface of the blank in the final stages of turning/sanding/finishing, you will have done the same stabilizing process to the exact portion of the blank that remains, but from the opposite direction.) So you can see that doing this is likely to be an effective way to ward off potential future problems on blanks that benefit from some form of stabilizing. When I do this step, I apply as much CA as I think will be absorbed, usually more than a "light coat". The whole process is dependent on the absorbency the blank material. I will use acetone on a cotton swab to remove oils to improve absorbency on oily woods.

 

[TonyW]

My thanks to everyone who replied to my query. I will try flooding the inside and ends of the blanks with thin CA before gluing the tubes in with epoxy.

TonyW

 

[low_48]

You can also induce cracking with aggressive drilling which builds local heat, and the same with sanding. CA will not benefit those mistakes, nor will it improve movement with wet wood. Most olive wood I've seen is dunked in wax. If that is the case for you, remove the wax, weigh the blank, place it in a warm place, and don't turn it until it stops loosing weight. Maybe 6 months!

 

[SDB777]

I am wondering how much a thin piece of wood can possibly move while being epoxied to a piece of brass tubing in order for it to crack apart?

-I wouldn't have any thoughts this could happen on say a 6x6 that is outside in the rain and sun all the time. But the thickness of the materials we deal with are in the thousands-of-an-inch thickness with being CA'd on one side and glue(of some sort) on the other.



Imma go search the internet(cause we all know it'll be true if I find it on Al Gore's interwebs) to see how much timber of this thickness can move...I think it'll give me something to do today other then watch that cobweb in the corner blowing around(yes, my pain meds are awesome).

Knew I had the book, but I needed to find it online to share.... >>>PDF LINK<<<
page 3-8 has the equation to use, the shrinkage rates are on the previous pages, and the rest of the equation can be figured on the two following charts..... I'll admit right up front, Olivewood is not on the list anywhere, and my mind says 'no to math while taking meds for my back'....
But it's a fun read anyway to understand a little more how and why wood moves.




Scott (hope the customer is happy with the fix) B