Ambient heat VS wedge retention

AndreLinoge

AndreLinoge

Joined
Nov 20, 2014
Messages
639
I carry an axe to work daily. My "office" is a control booth on a debarker situated over top of all the hydraulic pumps and the floor is an average of 125 degrees according to an infrared surface temp meter. Just last week, i had a nasty flap on a log that took a fair bit of sustained power chopping. Bouncy target, inefficient work.. Was slinging a single bit that weighs right at 4lb (my average work axes are 3 to 3.5). It was a pretty hot day, too so the axe was baking in the booth a little more than usual. After defeating the loose chunk of pending disaster, I noticed my wedge had started to walk out. Now, I dont always safety-wedge my axes, and this one was hung without one; but one of my other favorite axes has no safety wedge and has seen some much harder (angry) chopping in the same situations. Its never slipped its wedge. What I'm wondering is, did heating the oil in the handle and wedge cause it to slip its bond? The floor of the booth does have a good bit of hydraulic oil coated wood dust where I put the axe when I'm operating, so maybe it wicked up inside the wedge and added to its issue? Anyone ever run into this before, or does it make sense in any way? I will test the retention again this coming week on that same axe with a reset wedge after it gets warmed up. If it slips again, I think this environmental stress (high ambient heat) on a tool might need considering by some hangers/users.
Also, if I were to put a wood cross wedge(s) in, should I split the long wedge before hand or notch it and split it with the second one? I would think i would need to cut the actual secondary kerf into the handle, but I've not done wood cross wedges before. I would prefer not to, but i will use a metal safety wedge of some sort if I have to.
Thanks.
 
My truck gets pretty hot in the summertime, and I never had that issue. It is really humid here. I imagine square peg is correct. I put axes in a sealed box once and it got crazy hot. Not only did the handles warp, but they sweated out blo.
 
I think something like 30deg F effects the equilibrium of moisture content in wood by about 1%.
Thing is though you leave wood in an environment that is hotter and it is very likely to have less humidity than the surrounding area. Cars with windows up, trunks.
The answer is to get the haft as dry as you can before you hang it and then try to seal it some what and protect it from moisture.
 
All my work axes are roughly the same age of hang (and thats not terribly old) plus the eye wood is always oily. Either linseed or hydraulic. Nothing seems dry about it is why it struck me as odd. If it slips more I may make a fatter wedge and crush it in with a bottle jack. I despise those metal safety wedges, but sometimes its required.
Appreciate the input, fellas.
 
Nice thing about a wedge that backs out on it's own is you can pull it and then stick in another one. Try roughing it up (coarse sandpaper across the grain, for instance) before the install. The existing wedge may be too smooth, not acute angled enough, the handle kerf cut may be too shallow etc etc. No need to use a bottle jack to set a wedge (also it's too slow and the wedge might resist and break) ; a sound whack with a heavy hammer provides plenty enough psi.
 
You can take the loose wedge out. Use a drift and knock the handle off. Check that the kerf is at least 2/3 the length of the eye. If it isn't, make it so. Measure the length of the kerf. Put the head back on. If the space in the kerf is thin and uniform get a hardwood wedge. If it is a wide gap and off and missing pieces get a wide softwood wedge. Cut the wedge to the length of the kerf. I usually remove the extra from the thin part of the wedge. Do any manicuring needed. Cut the wedge to the width of the eye. SOAK the wedge in blo. DRIVE it home. It should stop about even. Even out the wedge and proud part of the handle with each other with a sander. Once even slather it in blo. Let it suck it all up. Do the rest of the handle. Store it upside down for the night. (Head down, handle straight up.) The next day take it back out. Use a screwdriver sideways or a sideways file and a hammer and convince the wedge it wanted to be recessed. Once it is down enough to make a difference keep applying the blo to the proud part of the handle. Some people soak it.


The proud part of handle will be forced over the eye a little locking the axe head on to the handle. The proud part of the handle will swell, locking the recessed wedge in. Making it very difficult for it to come out. It is an extremely solid method if done correctly.

I have had one come loose when done like this but it was because I committed an error.


 
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Woodcraft said:
The proud part of handle will be forced over the eye a little locking the axe head on to the handle. The proud part of the handle will swell, locking the recessed wedge in. Making it very difficult for it to come out. It is an extremely solid method if done correctly.


Click to expand...

The ultimate! This method seems to have evolved from via numerous discussions on this forum (I'm thinking Square-Peg's input) and ought to do the trick. 'Proud' hafts (leaving 1/4" sticking out) was the instigator of this logic and runs contrary to the traditional way factory hangs have always flush cut. The concept is sound (proud hafts) and some of the boutique Swede products (former Wetterlings) even picked up on this over the past few years. In this situation the uncompressed portion of the haft furrs over or swells to lock in the wedge.
 
300Six said:
The ultimate! This method seems to have evolved from via numerous discussions on this forum (I'm thinking Square-Peg's input) and ought to do the trick. 'Proud' hafts (leaving 1/4" sticking out) was the instigator of this logic and runs contrary to the traditional way factory hangs have always flush cut. The concept is sound (proud hafts) and some of the boutique Swede products (former Wetterlings) even picked up on this over the past few years. In this situation the uncompressed portion of the haft furrs over or swells to lock in the wedge.
Click to expand...
S Square_peg should do a detailed step by step.
 
Woodcraft said:
S Square_peg should do a detailed step by step.
Click to expand...

You just did a pretty good one.

It's a trick I read about in an old logging book. I do it a little different than you. I use DPG/water 80/20 (generic Swel lock) on the wedge and kerf before assembly. I drive the wedge until almost tight, cut it flush and then leave it over night. The next day I drive it down that last 1/8" like you did with the file except I use a scrap of old leaf spring as my punch. Once the wedge is down then I hit it all with the BLO. Sometimes I go once again with the DPG before I switch to BLO the next day. I don't want the BLO to stop the DPG from getting down in there. But once the DPG is in I use the BLO to protect the end grain.
 
rjdankert said:
Exaggerated example (not mine):




Bob
Click to expand...
I hung an ax that I knew was going to face abuse once. Left at camp. Facing moisture as well as periods of heat and dryness. Perhaps even periods left outside in the chopping block. Knowing it would not be properly taken care of for years I left it proud and long. Drove a long wide wedge in it as far as it would go. Cut it off proud roughly a 1\4 strong and sanded it flat. Then I drove a barrel wedge in it. Right in the center of the meaty part of the eye. That one is still going strong. Your picture reminded me of that. I am not a fan of metal wedges and I do not think they are needed. Short of a quick/short term fix. But sometimes when you know WHO is going to be using the ax.............
 
This is all sound and good advice. These practices have been learned over the years, and verified to work well all over. I am going to blame lack of wedge thickness for this slip right now. I reseated it, countersunk it more, and also cut a fatter wedge and dropped it in the linseed baggie to replace it when it slips out again. There is a piece or 10 of sun seasoned hard maple out in our "its got metal" pile that I will be abusing monday to see if re-oiling and resetting the wedge helped. I have a feeling that its just not 'wedgy' enough for the use it's seeing. I had to take a good amount of hump off the sides of the tongue to get it matched to the eye on that particular handle, and maybe that means the kerf isnt tight as it needs to be down inside the eye. If its only getting a really savage bite at the top of the kerf, then any change in the state of the wood could change that. I still think softening the oils with a heated surface was the beginning of compromising a skinny wedge, but who knows for sure. It was fine when it was cold, but maybe I'm overthinking it.

Great pics and contributions, guys.
 
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