I make gunstocks (not for a living, that is for sure!) and I was recently sent a rather rare stock to do some restoration on. There was a 5″ crack on it when he sent me and I swear when I opened the box I saw it add another inch to the crack.
It got me to thinking about storing gunstocks, since the vintage machinguns and such that I work on are VERY valuable, what is a good humidity to store them at that will ensure they don’t crack. I am more worried about old original wood cracking than mine, as I make mine about 10-15% thicker in the thin places
Is it mainly the change from one humidity to another that causes cracking, such as taking it out of a temperature controled safe to an outdoor range?
What humidity do museums that feature furniture maintain? I now have a number of customers concerned about this issue and I want to have a solid answer for them.
What other issues should I be aware of?
Thanks in advance.
Replies
Gun stocks undergo many more stresses than furniture will. Could the crack be because of poor grain choice at a particular area in the stock? Some presentation pieces were not ment to be fired at all.
I've seen beartiful reproduction Pennsylvaina rifle stocks split at the first proof firing.
If you increase the humidity to preserve the stability of the stock, then (IMHO) you will run the risk of metal corrosion. 10-15% should be OK for storage. Military pieces that I've disassembled usually had olied stocks. If the wood was green when they were produced, the oil may have stabilized them. When they dry out, they may crack.
Recently I restored a 1917 Lee-Enfield for a relative. Someone had had tacked on a cheek piece, and grafted on a fore-end cap, then varnished it. I disassembled it, and found that the original oil that the stock had been treated with, had penetrated the wood entirely. The wood was walnut. After removing all of the stuff, I re-oiled the stock, and it looked like the day it was issued.
I say you should invest in a humidity controlled cabinet to store them in. I know they exist, just don't know where to look. Keeping the humidity constant is the most important thing.
Your customers should, if possible, dismantle the wood from the gun and wrap it tightly with several layers of Saran wrap, and tape, before shipping. A sealed plastic bag wouldn't hurt either. I'm guessing these come from all over the country and you don't know what humidity conditions they see in shipment.
Also, will there be extreme humidity differences between the place of origination and your place?
One of the things that make a gun stock pretty, i.e. wild grain, is the one thing that can most cause stress variations in the wood. In very straight grain wood, the stresses caused by humidity changes will be more equal throughout (balanced) and the wood will be less prone to cracking, checking, warping, bowing, etc.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
I don't have my copy handy, but the book Understanding Wood covers this topic. An excellent read.
This forum post is now archived. Commenting has been disabled