How To Guard fitting and jb weld

Justin Schmidt

Justin Schmidt

Joined
Feb 18, 2016
Messages
2,209
Since im forging now im gonna focus on just hidden tangs. This may sound like a dumb question but ive heard of alot of guys using jb weld to attach the guard. My question is how? If you press fit it on when your hammering ut down would that just remove the jb weld you put in the tang? Or do you apply a small amount as if it were solder on the top if the guard?
 
If you press fit it (cold) then you won't need anything else to secure it.
JB weld can be used to fill the gap if you have a sliding fit
If you press fit the guard, there is no gap.
 
Ok that makes more sense then. I just press fit a guard and there is a minute gap so i was wondering.
WYYLZXU.jpg

Ignore the hideous scratches
 
well if there is a gap...then you would need to fill/seal it
is the gap on the horizontal plane of the pic where the shoulders are?
or on the vertical side where the tang slides in
 
If you get it tight, the JB Weld mainly serves as a seal.
 
It's hard to tell from your pic, but I think I've been having the same problem on my first guard, which is actually now the second one for this knife.

I just can't get rid of the tiniest gap behind the shoulders where the guard buts up against them, no matter how big of a radius I file on the guard opening. It's a press fit and I had to refile in the shoulders a third time now because I ended up upsetting (mushrooming) them after trying to bang it on there good and tight.

I end up taking tiny amounts of more steel off the guard hole and then I end up making it slightly too wide and have gaps in the side, which I then use a ball peen hammer to close up and resurface the guard face, then the same thing happens again. I had to make the new guard because I ended up doing that so many times of the last one that it's not at the thickness I want anymore for this particular knife.

I'm at a loss, and I've used all the tips, tricks, and techniques that I can remember picking up over all the years from WIP's etc.

I even hand lapped the carbide faces on my B. Bump file guide with my Diasharp diamond stone just to make sure I was getting perfectly flat shoulders, but can't get rid of the tiny gap.

Sorry, not trying to take away from your thread Valknut, but I literally just came inside from goin at it again with no luck, again lol, and saw your thread.

Hopefully somebody here has some fresh ideas. Using wrought iron FWIW.

~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
coldsteelburns said:
It's hard to tell from your pic, but I think I've been having the same problem on my first guard, which is actually now the second one for this knife.

I just can't get rid of the tiniest gap behind the shoulders where the guard buts up against them, no matter how big of a radius I file on the guard opening. It's a press fit and I had to refile in the shoulders a third time now because I ended up upsetting (mushrooming) them after trying to bang it on there good and tight.

I end up taking tiny amounts of more steel off the guard hole and then I end up making it slightly too wide and have gaps in the side, which I then use a ball peen hammer to close up and resurface the guard face, then the same thing happens again. I had to make the new guard because I ended up doing that so many times of the last one that it's not at the thickness I want anymore for this particular knife.

I'm at a loss, and I've used all the tips, tricks, and techniques that I can remember picking up over all the years from WIP's etc.

I even hand lapped the carbide faces on my B. Bump file guide with my Diasharp diamond stone just to make sure I was getting perfectly flat shoulders, but can't get rid of the tiny gap.

Sorry, not trying to take away from your thread Valknut, but I literally just came inside from goin at it again with no luck, again lol, and saw your thread.

Hopefully somebody here has some fresh ideas. Using wrought iron FWIW.

~Paul
My Youtube Channel
... (It's been a few years since my last upload)
Click to expand...
so assuming your guard surfaces are both flat and parallel (2 different things)
and your tang is surface ground parallel
and you used a carbide file guide for the shoulders, finishing with a file, correct?
and you milled a slot in the guard .002 width undersize from the tang dimension and square to your flat and parallel guard surfaces

following these things, you should not have that gap at the shoulders.
done correctly it's water tight with no other sealing required.

But each step must be done carefully and correctly or you will see some gap and it only takes .002 to see it

eGXltLW.jpg
 
HSC /// said:
so assuming your guard surfaces are both flat and parallel (2 different things)
and your tang is surface ground parallel
and you used a carbide file guide for the shoulders, finishing with a file, correct?
and you milled a slot in the guard .002 width undersize from the tang dimension and square to your flat and parallel guard surfaces

following these things, you should not have that gap at the shoulders.
done correctly it's water tight with no other sealing required.

But each step must be done carefully and correctly or you will see some gap and it only takes .002 to see it

eGXltLW.jpg
Click to expand...



Hey Harbeer, thanks for the post.

I don't have a mill, but I did drill and file the slot under size, and also used a round diamond "burr" to hollow out a good bit of the guard thickness from the backside of the slot oversized so I only have about 3 mm that actually needs to be fit up. I used a file to open the rest of the way, and then the rest was file a little, check fit, file a little, check fit, etc.

My tang is tapered until about a few mm before the ricasso, but my ricasso is flat and parallel and so is my guard, which I flattened using my disc grinder. I actually bought a digital mic before I started this knife so I could accurately check these things.

I used a file guide and file to square up the tang shoulders, but I finished the very last bit with an EDM stone to leave a finer finish than file and I ran a good straight edge over the file guide and the shoulders a at a few different angles to make sure there was absolutely nothing left proud of the carbide faces.

They are a few things I will do differently on my next with regard to tapering the tang behind the guard and such, but I have checked everything and each time I have come to this point of the guard fit up, there are very tiny gaps between the guard and tang shoulder. Not big enough to any light to really pass through using bright LED lights to check, but enough to create a bit of a shadow which looks pretty obvious to me.

The thing is, I can slightly tap the bottom or top of the guard and the gap on the side I tap will actually close up, while the opposite (spine or choil side) will open up a little bit more.

This led me to believe that my shoulders weren't completely straight inline with each other, so I ended up hand lapping the carbide faces on my file guide to make sure they were absolutely flat, and then I made sure to put some post-its on the ricasso under the file guide too make sure it would not slip while filing them, and cranked it down as hard as possible as well.

I feel like there is something I'm missing, but I will try a few more "file and checks" with the guard slot to see if it helps, but I'm afraid the same thing will happen as last time and there will be actual gaps in the width of the slot and I'll have to peen the face and re-surface it again.

The thing I'm most worried about now is hammering the guard on too hard to try an close the gaps. I honestly can't have the ricasso shoulders mushroom again because the ricasso is short as it can be without looking off, not too mention there would be even less surface area for the file guide to grip if I had to fix re-file them again.

Anyway, it's still a pretty tight fit and takes a few good hits to knock the guard back off, so I'll try to file it a few more times and let ya know how it goes.


~Paul
My Youtube Channel
... (It's been a few years since my last upload)
 
No mill, no surface grinder. Just a chunck of marble and files
8iMSo4A.jpg

I think im gonna try and pack some jb weld in there then once it dries scrape the excess with a razor.
 
Ok, I see the gap now. Those gaps can usually be fixed by lightly peening the face of the guard around the guard slot will a ball peen which pushes the metal back in, then just grind off a few thousandths to resurface the face of the guard and it's good to go after a little clean up in the guard slot with a file.

I'm having issues with the very slight shadow gaps behind the tang shoulders.

~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
Cold steel it kinda sounds like the radius from shoulder to tang is lower than the shoulders. I hope that makes sense. If its too much of a radi then it won't be parallel to the shoulders. I can draw a pic if needed
 
Hah, oddly enough I just went outside for about 10 minutes and was able to get it "good and tight" ;)

I just had to steepen the angle of the "radius" that leads into the guard slot so it almost provides as place for the shoulder to rest in. I did do this on the first guard I made and it didn't work, but I guess since I was extra careful this time while setting up the file guide as used post-its on the ricasso to make it wouldn't slip, the problem on that one must have been due file guide slipping the slightest amount the previous time I filed in the shoulders, which caused them to be out of line just a tiny bit. As I said, the ricasso is pretty dang short on the one I'm working on so there is hardly any real surface area for the file guide to grip without slipping.

I guess I just finally did everything right this go around. Nice to know I'm not goin crazy at least :confused: lol

I do have to give a shout out to Nick Wheeler for all his great tips, including the use of post-it notes under the file guide to add a bit of friction (as well as protect the ricasso from being marred by the file guide).

Unfortunately, I did notice that one of the corners of the tang shoulders is slightly mushroom again, but I can probably fix it, and if not, oh well, I'm not turning this in for a JS fit & finish test knife. ;) I definitely have learned a lot regarding what not to do on my next one though.

Out of curiosity I did do that water seal test, Harbeer, and it does pass, so thanks for that tip. I'm still probably going to use a bit of JB-weld on this one though, just to insure its completely water-proof.

~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
Thanks.

I don't have a jig for hammering the guard on, I just use a piece of gasket material with a slot cut out on the back of the guard, then a mild steel plate with a slot on top of that, then a scrap piece of leather with a slot on top of that, and then finally a piece of pipe hammered in on one end to squish it a bit so it would fit the back of the guard better so when I hit it with a hammer the force is more directed around the slot in the guard where it needs to be driven on. Similar to some you may have seen in various WIP's online.

I've have been wanting to get one of the jigs that bolts on the tang and has a couple other bolts that when tightened force another plate forward that pressed the guard on, but I can't find them. I think I remember seeing them for sale at USA knifemaker a few years ago but I recently checked and didn't see them anymore. That would definitely solve any problems of the guard accidentally hitting on of the shoulders before being completely on and thus mushrooming them. Maybe I'll try to make one sometime, but I'd rather just buy one of them lol.

~Paul
My Youtube Channel
... (It's been a few years since my last upload)
 
valknut said:
No mill, no surface grinder. Just a chunck of marble and files
8iMSo4A.jpg

I think im gonna try and pack some jb weld in there then once it dries scrape the excess with a razor.
Click to expand...
Jb Weld intend is not to hide your mistake ...it s good for sealing bolster from BACK side .If blade is carbon steel , imagine what will water do when get inside if bolster is not sealed with epoxy ?
 
Last edited:
I use a "sharpened" Starbucks wood swizzle stick, some WD40 and a shop rag to clean up the joint when using JB Weld.
 
C coldsteelburns if the sides of your ricasso are not parallel it can lead to filing shoulders that are perpendicular with one side of the ricasso but not the other. Even small deviations can appear as gaps, especially gaps that don't let light through (because on side is making contact while the other does not).
 
after my first press fit, i color the guard on the face and the shoulder curves with permanent marker, then tap it on again. anywhere that is missing the color needs to be filed.
 
Natlek said:
You don t want to use razor in that place . Use piece of bronze or cooper to scrape the excess epoxy.Razor a hard steel and will make scratches , how you will remove them there ?
Click to expand...
A new razor used to just slide under the epoxy (almost parallel with the piece you are cleaning up) will not scratch. Just slip it under the edge of the epoxy and push it straight into the corner to pop the epoxy free. Don't think "scrape" think "skim". Or use the brass rod thing. Of course getting it clean before it sets is ideal.
 
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