Moisture content

[hortonstn]

What is a good moisture content for a blank to have to use for stock wood

[Daryl]

9% for bow wood. I don't know about gun stocks. Likely similar.

[alacran]

7% seems to be the common standard. However, that claim by wood sellers is really saying what the moisture content was when it left the kiln.
How the wood is stored afterward will affect the actual moisture content.
 Most guys buy blanks that come from East of the Mississippi. Most builders do not have a moisture meter.
It is not a problem if the gun that is being built says in a humid environment. Real problem if it travels to the southwest.

[smart dog]

Hi,
I have a stock sitting for a month in my shop because the moisture content was 12%  I want it to be 7-8% before inletting the barrel.

dave

[hortonstn]

Thanks For your input

[Clowdis]

A stock will take on whatever moisture you have in your environment. You can dry it to 7% but if you leave it in a 12% environment it will become 12% also. I have built rifles in the relatively high humidity of NC and sent them to Wy with a customer. After viewing the same rifles a couple of years later they looked terrible after drying out in the much less humid WY environment. Same thing for an unheated shop vs. inside the house, the wood will shrink. What I'd do is let a kiln dried stock sit wherever it's going to be stored for a few months before I began carving on it.

[Daryl]

IIRC from the Bowyer's Bibles, that wood stored in an average humidity of 50%, will attain a moisture level of 9% once it stabilizes.
I do believe this info was in the first book.

[D. Taylor Sapergia]

I store my bandsawed blanks in the rafters of my basement shop.  My shop stays the same temperature winter and summer, ie:  60 F.  Tested with a moisture meter I bought from Lee Valley Tools, my stock wood stabilizes at 7.5 %.  In 2007 I took a longrifle to Dixon's Fayre and had sent the rifle weeks earlier to the Dixon's Gun Shop.  Just before the fair, I retrieved my rifle, and checked it over.  The wood had swollen around inlets and looked awful.  Even so, it won a lot of ribbons, but I was marked down for poor inletting, especially around the tang, where the wood had swollen badly.  After sending the rifle home to Central British Columbia where the average RH is around 35%, the stock lost it's Pennsylvania sweat and the inletting too returned to it's former perfection.  That was an eye opener for me.

[Clowdis]

IIRC from the Bowyer's Bibles, that wood stored in an average humidity of 50%, will attain a moisture level of 9% once it stabilizes.
I do believe this info was in the first book.

Good information. A piece of wood stored in 50% humidity cannot have a 50% water content obviously, but I had no idea what the relationship was. Thanks!

[Daryl]

Pleasure reiterating info gleaned from 1 of a set of 4 books- from memory, yet!!! 

[JBJ]

Actually, wood equilibrium moisture  content (EMC) is a function of both temperature and relative humidity. There are a multitude of tables and elaborate curves but the following simple table provides all of the info needed in a very concise manner. Using this table, you can readily determine the EMC for wood given knowledge of the various parameters. Looking at the table we can also determine that the RH in Taylor's workshop averages between 35-40% since he gave us the EMC of his wood and the average shop temperature  . Hope that this helps take some of mystery out of the relationship. Full disclosure - much of my working life involved a research lab determining wood properties.

[D. Taylor Sapergia]

Yes the barometer on my shop wall indicates the RH in my shop is around 35%.

[Stonehouse john]

I do saw milling, timber-framing, and furniture building in the northeast where both temperature and humidity swing wildly throughout the course of the year (even week to week sometimes).  Here's a simple analogy I find useful to illustrate lumber drying and moisture content to folks:  think of drying and storing your lumber just the same way you'd think of doing that with your laundry. 

People get very hung up on things like "finished moisture content",  kiln-dried vs. air-dried, etc.  But really...it's all just laundry.  Dry one tee shirt for an hour on the highest setting in the cloths dryer (kiln) and a second tee shirt on the cloths-line out in the yard (air dried).   Yep, they'll dry at different speeds, and when you take the cloths-dryer one out it'll likely be "drier" (lower "finished moisture content") than the other one, but when you fold them both and put them in the same drawer, they'll reach an equal moisture content very soon.  And that moisture content will be different on a humid day than it is on a dry day.  And it'll be different tomorrow than it is today.

I talk to folks who are completely convinced that a good quality furniture piece or gun stock can't be made from air dried lumber because kiln dried material is both "drier" and "more stable".  It will probably be "drier" on the day it leaves the kiln, but in exactly the same way that the cloths-dryer tee shirt is drier.  And as far as "stability" goes, moisture stability is a myth, as Taylor and others have said above.  But there's also a structural stability element which can be effected by the drying process and, IMHO, air drying is actually much better for lumber in regard to that.  I've never shrunk a shirt by drying it on the cloths-line but my petite wife now wears several several things I've ruined in the dryer.  And none of the beautiful early gun stocks we all admire are likely to have ever seen a kiln.

Anyway, the moisture percentage number that you're looking for is just not a number any of us can really give you.  We can give you the one that's best for us, but not for you.  The best answer for your time and place is to put your stock material where the temperature and humidity will most closely match wherever the finished gun will be stored/used, measure the moisture content periodically, and wait until the moisture reading stops changing appreciably (either up or down).  That'll be the right number for you.

-John

[Ron Scott]

Thanks for sharing the Moisture content table. I printed copies for my students. For anyone relying on a moisture meter for you measurement, be sure it is set for the specific gravity of the wood species you are using. My Wagner meter can be off by 2% if it is set for the wrong species. I have a 24 year old blank of English Walnut that is stored in nearly the exact condition Taylor describes, it measures 8.4 %. I am pretty certain it will not change unless I drastically modify my shop-storage environment.

[rich pierce]

Helpful analogy Stonehouse John. Thanks.

[D. Taylor Sapergia]

I worked for a gunsmith in 1979 through to 1984 creating the Fraser River Hawken we sold out of his shop.  He bought walnut by the crate from Oregon and California and they were a cube about 5' square.  When a crate arrived, we would systematically weigh every blank on a postal scale ( he didn't use a moisture meter) and then once a month thereafter until there was no appreciable change in the blank's weight.  During that time, we got to admire each piece of wood and set them aside for special guns.  We didn't stock many rifles in maple 'cause Don liked working with walnut...plain and simple.  His carving machine which he said cost him the same as a new Lincoln, carved 12 stocks at a time.  His method of determining the wood's suitability for working worked perfectly.  It's always a pleasure to attend a rendezvous somewhere and find folks shooting his Robinson rifles, and see them is such great shape.

[flinchrocket]

Taylor, Is Fraser River Hawken a specific Hawken rifle or just a name he used for the rifles he produced?