Home Forums Hunting & Shooting Hunting Rifles Dimensional Stability Myth

Sitka deer- I made him a pretty good pile of boards out of it. I didn't get anything. He is a good friend that will do about anything for me. He was going to make some cabinets or something. I have a post oak log in my front yard that you can have if you will pay the shipping. It is five and a half feet across the stump and about fifteen feet to the first limb. It died and I had it cut down. I don't know anyone that has a sawmill that can handle it even if they would take one out of the yard. miles

WOW!!! That is a lot of lumber!
<img src="/ubbthreads/images/graemlins/grin.gif" alt="" />art

dang, this is an interesting thread...

Years ago , my father and a buddy of his that owned a sawmill, got into a deal with a bunch of Menonites who had a gig walnut tree they wanted sawed.
Dad's cut ( Iknow, bad!) was a billet? plank? about ten feet long, 3 feet wide, and 3 1/2" thick! He wanted this straight grained walnut for target stocks, and it made some beauties, let me tell ya. It was dead dog straight as an arrow!

I used the last one about five years ago, and the blanks were cut in 1965, I believe.
I think it was either Roy Dunlap, or Alvin Linden who said
"Any wood will do for a gunstock - as long as it's walnut!"
I know my father told me that when he was showing me the ropes, and it was one of those fellas that he quoted. Both were masters of the craft...
Catnthehat

DixieFreedom,

Try http://www.matweb.com for materials properties.
I would check the thermal coefficient on something like 6061-T6 aluminum unless you know of a specific alloy being used.
Sorry this is a little late in the thread.

Thanks for the link! I guess I was just splitting theoretical hairs really.

Anybody out there know of a chain store that might carry that G1 epoxy? My 10/22 project is coming along and I could use some yesterday! Nonetheless thanks very much for the other links. A fellow at work says that Brownells carries it too, but I have not checked yet.

Dixie
I have found little difference in the various formulas I have tried. G-2 is the only one that clearly stands out as better for use on oily woods, but the rest are really very similar...

There should be a boat shop around that can seel you some epoxy with a very slow cure. It should work just fine. I have never found a slow cure epoxy that caused any problems...
art

Well Sitka;

argggg. I think I am just going to use some true oil and hope for the best. Won't be hermetic but it ought to better than nothing.

What are your thoughts on true oil?

Tru-Oil is wonderful stuff... but it does nothing to seal the wood. Actually it is quite the opposite. Oiled wood absorbs and gives off water faster than bare wood.

If you are having that much problem I could mail you a little bit to get you through a stock... I have it on hand in a bunch of different flavors...
art

This can be placed in the "for what it's worth" bin.
A 20 degree temperature change will cause measurable dimensional change in aluminum, steel, brass, glass, water and any other material or medium. To what extent this is a problem with regards to rifle stock is hard to say. Most of the synthetics are resilient enough to tolerate quite a bit of movement by the block.
I really don't mind the laminates but do think the sealing and re-inforcement of them is just as important as any other wood product. GD.

GD
Point taken, however the important thing to remember is that the movement is minimized by the fact both substances move. The difference in their movements is the key.

Aluminum moves more than steel, but the differences between them in terms of a rifle action and say an aluminum bedding block is so slight as to become meaningless.

As to sealing laminates, it probably does help, but the glues holding the laminates together are waterproof, so laminations are isolated. Also, the pressure they use to press the laminations together (vacuum press, I believe) forces a lot of glue into the wood.
art

While the glues used on the laminates are just fine the wood often is not. When these split, it isn't on the glue joint but is where the low grade birch veneer gives out. With the laminates I think it is quite important to provide some sort of re-enforcement against splitting. This can be crossbolts or dowels or concealed screws but something should be used.
Im speaking here of the Rutland plywood laminates. I don't think the walnut acrabonds have the same sort of problems. GD

GD
I am unaware of any splitting problems with the laminates, but can see where that could be a possibility. I find them all a little hard to look at... But that is just me...
art

Well...

My 10/22 project is moving along. I have not yet found decent epoxy. I did drive a half hour south of here to "big-city" Frederick MD and the hobby shop guru talked me out of the specific brand they had- said it would be hard to apply like a paint and that it would cure yellow. It was called "Slow-Cure"

In any case, since I is busier than a paper hanger with the hives, and a bit impatient, I just went and bought the Birchwood-Casey sealer.

I also bought some loctite brand goop for screws etc, the type that comes apart, WOW! 8 bucks for a micro tube! OUCH.

Then later I got twice as much "Devcon-Thread-Locker" blue goop for about 2 bucks. Gonna give it a try. I know that loctite is legend, and we use it in the power plants from time to time, but maybe that Devcon will work. Worth a try anyhow.

Sitka deer, I went down to a pile of cross ties that I have today and there was a walnut log about 12-14 inches at the butt end that I had forgot about. It has been laying there for probably four or five years. I took it over to the saw mill and now have a cant 3 1/2 x 6 x 10 ft. The butt is good on all sides for about 4-4 1/2 feet. What should I do now. I don't know what a stock blank should be sized at. I think that maybe I could get two out of the butt and maybe another from the top. If you are still making stocks I would give it to you. I am not going to make a stock any way soon. miles

Miles
I much appreciate the sincere offer, but I am admittedly picky about the wood I use to build stocks. Not to say there is not a serviceable blank or two there, but let me give a quick stock blank tutorial... as this is about dimensional stability it may be a good place to put it...

The center of the tree and even the whole tree in the case of leaning trees is called "reaction wood" and it is different. the fibers are shorter and there are some other cellular differences.

It is weaker and far more prone to problems with internal stresses. There is an interesting bit of trivia that angiosperms (hardwoods to most folks) produce excess reaction wood on the bottom side of affected areas and gymnosperms apply it to the top side. An analogy could be made that hardwoods push up limbs and softwoods pull them up.

This reaction wood in limbs is why limb wood is good for firewood... not blanks...

A quarter-sawn blank is more stable than a board-sawn blank because there is a critical characteristic in wood that causes it to change size in three different directions differently with moisture content changes.

It moves little in length, about 12% in tangential (board-sawn)and about half that in the radial (quarter-sawn) direction. These numbers are for walnut being dried from about 25% moisture content to dry at 6%.

If you think about that you will realize that a board sawn off angle (neither board nor quarter-sawn, just different) will try to do some strange moves if the moisture content changes.

Different woods move differently in relation to moisture changes after drying ("stability in service") and that feature can make a seemingly good wood species a poor choice.

Some species are so stable the difference is nearly moot in their changes. For example mesquite is the most stable wood commonly used for stocks. The difference between radial and tangential shrinkage is almost non-existant at just over 6% in each direction.

The thng that I find shocking of late is the number of Turkish circassian blanks I am seeing that are in no way perfect blanks being sold at exhibition grade, PLUS prices. Extreme runout through the wrist and all sorts of true defects and the blanks are selling for over two grand! For two-piecers!

I saw a blank a while back with 45% grain sideways through the wrist and it sold for $2,800 just because it was heavily marbled with black. The stockmaker inletted a cylinder of straight-grained english around the stock bolt to use it. It might not break. But $2,800?

Anyway, back to the point about small trees... Smaller trees produce less stable wood than older, simply because the wood is older and less affected by wind and other stresses.

Another interesting bit of trivia before I wind up this little ramble <img src="/ubbthreads/images/graemlins/blush.gif" alt="" /> is that fiddleback wood is stronger and usually more stable than straight-grained wood of the same species.
art

Sitka Deer

I just bought a used BDL stock to chunk my reminton 308 into. Currently it is a factory ADL synthetic with the cheap plastic stock that I hate.

I called brownells and a fellow suggested using acraglass gell with the black dye in it to finish the stock, (I was asking him about epoxy paints) He said it would fill up the checkering if that is what I wanted, and yes that sounded good to me.

I always hated BDL stocks but picked it up for 50 bucks cuz I thought it was cheap and right now available. Now I need bottom metal etc...

point being Mr Epoxy Guru! Where is the epoxy paint when you need it? Looking for Khaki.

Are you man enough to answer this one???? arggg heh heh heh well prove it pal!!!! ha hah hah hhah

quite frankly I is a bit frustrated in my search and I have tried all the local paint experts from car paint wholesalers to the local paint store

Only thing close is a epoxy paint tub repair kit from Sherwin Williams, 28 dollars, two part mix, stark white for tubs. yuck!

To start, I know next to nothing about epoxy paint... It is not nearly as waterproof as epoxy due to the solvents used to make it thin enough to spray and allow it to form a film.

What I do know is that acraglass gel would be about my last choice for a stock finish. I also know that painting epoxy over the finished wood is a good way to ensure premature failure of your epoxy.

I would be asking Rick Bin what he uses on his stocks and thinking of that as the correct paint. If you ask him nice he might even spray it for you with a few dead presidents for bait...
art

Why premature failure?

http://www.pyacht.net/cgi-local/SoftCart.exe/online-store/scstore/h-awlgrip.htm?E+scstore

Awl Grip

Marine epoxy paint. I think I have found what I been looking for. They used it out in the South Pacific where I used to work. Rust out there has to be seen to be believed as to how bad it is.