Got an interesting PM I thought we'd share wit you all...
Working with wood question
Good day sir! I've been watching your thread over the last few months and must say I'm very impressed! I am a machinist and budding gunsmith in Alberta and am currently working on scratch building a pair of Winchester highwalls. I bought some fancy walnut blanks from the states last spring which were covered in wax. Back in november i roughed out the first one and found it kept moving on me. (shrinking and warping) I've since de-waxed the rest of the wood and some are splitting too. Is this the nature of the beast? Or have I bought wet wood?
IE, is it normal to have to rough something out, wait a while, machine it to fit, wait a while, hand fit it to the receiver, wait a while, and then finish shaping the stock? Or should you be able to just do it?
Thanks for your insight!
Paul.
OUCH! sorry to hear, hope it didn't set you back too much $$$ Funny - one of my second or third projects were a pair of Father/Son low walls... thanks for the compliments!!
Wood moves, no matter what you do to it, it will eventually move, the smaller the piece the less noticeable it will be. Highly figured woods will be more unpredictable than straight grained woods - wood will expand more along the length of the grain than across. Anything with curl in it is a complete bastard. (and yes, that's the technical term)
I have not had any real problems with butt stocks but have had flint locks and forends move around and warp. and only one ever beyond recovery. if it is the forend you could steam it and bend it back fairly easily. There is a good video showing a method to fix a warped sporter here:
https://www.youtube.com/watch?v=eKz_I2DfesM
So, warping in general will probably be environmental, if you get lots of severe changes (well even moderate changes can do it) in humidity in your work area you will start getting the issues you described. (my shop goes from 70% in the summer to 20% in the winter.... I have to keep moving blanks around to keep them stable) best solution would be to keep them in a stable environment when you are not working on them (humidity controlled gun safe?)
My rule of thumb is buy rough lumber/blanks/whatever & let them stabilize for a week/10 days or whatever at least. After milling or cutting blanks, use immediately or as fast as reasonable. If they sit around longer I'll oil/seal them up. There is nothing wrong with letting apiece sit around unsealed, just so long as the humidity remains stable.
Cracking: - walnut burl and crotch pieces (especially when they are cut close to the bole/center of the tree) have a lot of stress in them & you should expect the stress to release/change when you start cutting into them, warping and cracking them. Cracks are not such a big deal so long as they are not in a critical spot (i.e. through the wrist) generally they can be fixed/repaired with cyanoacrylate glue and will actually look like a feature This sort of thing is happening to almost all the walnut I have on hand right now as they are all slices of the same bole of quite a large walnut tree
If you had purchased gun blanks I would expect them to be extremely stable and dry, like I said it's probably environmental - I'm guessing these have a lot of figure in them - the darker spots will be very hard and the lighter softer, if it has curl then the stripes alternate hardness - the softer material is probably absorbing moisture faster than the harder, introducing more stress & cracking. I invested in a moisture meter recently .... extremely handy tool!!
- response too long, sending another PM (PMs can only be 5000 words!!)
Normal process: I try to get things done ASAP once cut, and keep them stored in a stable environment. If I know something will be sitting around for a while - it get's oiled/sealed. If you do a bit and wait then do some more and wait without protecting against swelling/cracking/warpage. You are just asking for trouble IMO. You'll inlet something, come back in a week, it won't quite fit, inlet it some more come back in a week then there's a gap there... no fixing that - you'll have to bed it. however, they way most people work, I would say that is normal
CAVEAT: If I get something with a lot (and I mean a lot) of visible stress cracking that you know can't be recovered, I have been known to 'break it' drop it on a concrete step and let the cracks finish their jobs, that way I don't have to guess or find/figure out where a crack is going or what might happen. Then just 'deal with' what is left. at that point at least I know the worst of the stresses are out of the material.
Fore ends: once I get barrel channels and magazine tubes cut/drilled/inlet - I will oil the living crap out of the inside, not only helps mitigate warpage & cracking (though not completely) it also gives the fore end a little more elasticity in case you have to chuck it up in a vice again.
Butt Stocks: the only issue I have ever had is swelling which can make an inlet receiver no longer fit. I generally try to do a complete inlet in one session then seal it up somehow. Oil is not my favorite, I prefer to use something that will protect from future oils seeping into the receiver inlet. again Cyanoacrylate glues or you can epoxy bed the receiver.
FYI: Oiling and sealing as you work - if you are gonna leave if for a day or two, don't worry about it. a few weeks maybe if you don't have storage where you can control the humidity (gun safe) BUT oiled wood will take a toll on your tools, clog sandpaper pretty good etc. You'll be sharpening your chisels more, cleaning your rasps more and using more sandpaper. So pretty much 'only if you have to' and you want to try and avoid it when you get near to your final dimensions. i.e. when you are getting close to sanding/finishing. whatever you use may not be compatible with your chosen finish.
Fixing:
Cracks: as I mentioned they can be sealed up with CA so long as they are not threatening the structure of the wrist. Keep in mind the calibre of course, a crack in a .22 wrist is nothing to worry about - glue it! .30-06 ........ don't even try you really just have to get a feel of it see where the crack has started and figure out where it is going and if it is going to threaten the structure over all.
In a fore end, cracks tend to be more difficult since you generally don't have as much material you need to be more careful about gluing them - fortunately you don't have much to worry about with recoil on a fore end.
Warping:
Never had a butt stock warp, but you can bend wrists using heat - have to look that one up on you tube, I've never done it...
Fore ends & long guns, steam and clamp around your barrel (protect the barrel from the moisture) - once formed steam bent wood will generally stay put(ish) then oil the crap out of it. even better if you have multiple lugs or barrel bands to convince it to stay put.
Splitting:
hm. tough, if you have enough material cut the spit out and seal if not going to use it right away.
In a nutshell? "work on it at whatever pace you enjoy most, just keep your material stable"
Great question! - you mind if I post it on the thread?
-thanks
-sean