Putting a guard on a full tang knife.

Gonna have to be more specific. If you want a mortised guard, you will need the tang to maintain a constant profile or taper from the guard to the butt. If you don't want to do that, you will need to use a slotted guard and some other attachment method. Or, you could do an integral.

Or if you can weld (if you are gonna try this, I would suggest tig) you could try welding the guard on (this would also work with a slotted guard). If you do try this method, I would probably use a shallow hardening steel with a preheat. Not sure how well it would work with something more hardenable, I suspect you would be very likely to get weld embrittlement that may cause cracking prior to you having the opportunity to stress relieve. Either way, I would do this prior to heat treat. You can also tig braze a slotted guard on if you want to avoid the possibility of embrittlement, though you will need to heatsink the blade to prevent detemper if you braze/solder post heat treatment. Alternatively, you could use a high melting point braze and do it prior to the H/T. I haven't tried this specifically, but it should work fine, presuming you have the tools.

If you are going to weld, in lieu of trying to machine a slotted bolster, it may well be quicker to try making the guard from 2 pieces, each welded to their respective sides. I also haven't tried this, but I think it would be easy. fill in the gap between the pieces with either more filler metal or another piece of the same thickness as the blade.

I am sure there are a bunch of other ways, and I found a few on youtube by searching "guard to a full tang."
 
Yeah. I have done that method before. Works but I don't love it. TBH, I dont love guards on full tangs. I have always figured if you are doing a FT and you want a guard, just extend out the front/rear quillion and slap some bolsters on either side. I know it takes some more steel in your parent stock, but it seems the more elegant method. Otherwise you end up having to do a very thick slotted guard or you just have a piece of metal sticking out that blends poorly into the handle material.
 
Slot a guard and fit it tightly before heat treat. After heat treat pin it to your blade and shape the guard along with your scales. Here is a knife I recently finished with a slotted guard and tapered tang. Larry

PDNGGXFm.jpg
 
I'm wanting to put a guard on a camp knife. I was drawing the up yesterday and a guard really makes the knife look right. It's going to be a large knife 16" overall. I have another one going with a hidden tang and wanted to compare them. I was thinking of slotting the guard and soldering it on followed by some pins. I could do a short quillon but with a wide blade and 2" stock I'm somewhat limited. I also wonder about putting a stress riser in the worst possible place . I am looking for some different ideas to mine before I start cutting steel. I got my part of the taxes done so my wife will let me back out if the shop again.
 
I have a question about this as well, so i'm tacking onto this post, hope that's ok. I am doing a chute style knife in nitro-v with nitro-v bolster (2 piece pinned). I am planning on heat treating the bolsters, is that ok? I have fitted and drilled them already. I also intend to do a tapered tang. Should I taper and grind bevels prior to heat treat? I am using 3/16" stock, so warp shouldn't be as bad, but if I both taper the tang and grind bevels, there will be very little contact on my quench plates. That said, should I do just one operations pre heat treat, both, or neither? Since this picture was taken, I have shaped the bolsters to the profile, but have not contoured them.
chute.jpg
 
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joedhiggins said:
Gonna have to be more specific. If you want a mortised guard, you will need the tang to maintain a constant profile or taper from the guard to the butt. If you don't want to do that, you will need to use a slotted guard and some other attachment method. Or, you could do an integral.

Or if you can weld (if you are gonna try this, I would suggest tig) you could try welding the guard on (this would also work with a slotted guard). If you do try this method, I would probably use a shallow hardening steel with a preheat. Not sure how well it would work with something more hardenable, I suspect you would be very likely to get weld embrittlement that may cause cracking prior to you having the opportunity to stress relieve. Either way, I would do this prior to heat treat. You can also tig braze a slotted guard on if you want to avoid the possibility of embrittlement, though you will need to heatsink the blade to prevent detemper if you braze/solder post heat treatment. Alternatively, you could use a high melting point braze and do it prior to the H/T. I haven't tried this specifically, but it should work fine, presuming you have the tools.

If you are going to weld, in lieu of trying to machine a slotted bolster, it may well be quicker to try making the guard from 2 pieces, each welded to their respective sides. I also haven't tried this, but I think it would be easy. fill in the gap between the pieces with either more filler metal or another piece of the same thickness as the blade.

I am sure there are a bunch of other ways, and I found a few on youtube by searching "guard to a full tang."
Click to expand...
I can TIG weld and probably have a little bit of inco 625 left over from a job but I'm a little nervous to try it on a large knife. You mentioned brazing. What braze will hold up to heat treatment?
 
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There are copper based brazes that will hold up to typical carbon steel HT temps in the 1450-1600 range. They're not terribly common and I've never used them. Winchester push feed Model 70s use a copper braze like this to attach the bolt handle to the bolt, I believe in order to harden the bolt after the fact.
 
kuraki said:
There are copper based brazes that will hold up to typical carbon steel HT temps in the 1450-1600 range. They're not terribly common and I've never used them. Winchester push feed Model 70s use a copper braze like this to attach the bolt handle to the bolt, I believe in order to harden the bolt after the fact.
Click to expand...

skillgannon said:
I can TIG weld and probably have a little bit of inco 625 left over from a job but I'm a little nervous to try it on a large knife. You mentioned brazing. What braze will hold up to heat treatment?
Click to expand...

If you can get it to stick, most any of the nearly pure copper braze metals will work. Honestly, If you can TIG, I would probably just try that. Run some tests on scrap, ER70 series filler should be fine if you dont want to do it autogenously, presuming you preheat. I would probably try it autogenously first so you don't have to worry about having a part of your tang with a wonky carbon content, but with good normalizatio, this shouldn't be an issue. If you want, you could always use an offcut from the blade/guard material as filler, but I would run a lot of shielding gas and a wide cup to ensure no contamination.
 
i do bevels and the profile to 120 grit, but i always do the ricasso to 400 before fitting the guard and H.T. it will save a thousandth of an inch or so and keep the guard tighter. i only hand sand the ricasso after HT for the same reason, no machine. with the machine it is easy to take off more than you need to, making your tight slot wider. kevin, i used to do everything pre heat treat, but i am leaning the other way now. it will make for less work battling warps, especially with tapered tangs.
 
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