How To Guard fitting and jb weld

A couple of thoughts,

A lot of people know about Nick's WIP which is a great resource but Will Morrison's WIP is also excellent. If you haven't read it, find the time. Check page three for guard fit up.

https://www.bladeforums.com/threads/introduction-and-a-wip.1082411/

JB Weld, like other epoxies, works as a moisture seal under the guard. It's pretty strong too and takes about 600˚ to break it loose if you screw up. Don't ask me how I know. It should not be a replacement for a tightly fit guard as you know. With the blade in a vise and tang up I put a ring of the JB Weld around the tang just above the ricasso. Then I fill the guard opening with the epoxy and carefully slide it down the tang trying to avoid the tang dragging epoxy out of the guard slot as much as possible. As the tang drags epoxy out of the hole it will be running over more epoxy from the ricasso side. I set the guard in place with a 2.5lb drilling hammer and a length of PVC pipe. Do not hammer so hard that you are mushrooming parts. I use a larger hammer because it gives me a larger hammer face and the mass allows me to use a lighter swing, if that makes sense. The pipe has been warmed at one end with a heat gun and clamped in a vice enough to squash it into an appropriately sized oval. Leave it in the vice until it cools then touch up the end nice and flat on your 2x72. The PVC is very tough and will withstand a lot of hammering. Once the guard is seated you can clean up the guard face and ricasso with cotton swabs and alcohol. Don't over wet the swab. You don't want alcohol wicking up into the joint dissolving the epoxy. You just want to wipe the excess epoxy away with dry swabs then do final clean up with damp swabs. Keep checking for squeeze out for about 10 minutes and wipe clean.

As far as fit up goes, one tip I got from Nick was to use the belt sander to true up the shoulders. The carbide-faced file guide works great for this application. I have been frustrated in the past trying to square up the shoulders with a file, stones, etc. I'd check the flatness with a fresh razor blade and I couldn't feel any variation from the file guide but somehow it just wasn't perfect. When I started using the file guide against the platen on the belt sander it just worked better. If you have variable speed turn it way down and use something like a 400 grit belt.

The other thing is to get yourself a set of radius gauges. You can't see how the guard and shoulder radii are mating but by checking both individually with a gauge you can get a pretty good idea.
 
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i4Marc said:
As far as fit up goes, one tip I got from Nick was to use the belt sander to true up the shoulders. The carbide-faced file guide works great for this application. I have been frustrated in the past trying to square up the shoulders with a file, stones, etc. I'd check the flatness with a fresh razor blade and I couldn't feel any variation from the file guide but somehow it just wasn't perfect. When I started using the file guide against the platen on the belt sander it just worked better. If you have variable speed turn it way down and use something like a 400 grit belt.
Click to expand...

I start with the belt sander platen to get most of the material off the shoulder, but I was shown how to finish on a 9" disc sander.
So I use the disc sander and then finally use an appropriate file to "check" if there is anything raised left to remove
 
I don't like removing excess epoxy or JB Weld from those areas once dried. A few minutes after doing the glue up, I take a fresh folded baby-wipe and run it along all the surfaces and joints.
This helps get a smooth clean look. If you make sure there is no cloudiness from epoxy residue on the guard at that time then you avoid trying to get it off later.
 
Harbeer,
I forget now whether or not I saw Nick using a belt or disc...probably a disc. Belt or disc, either is good.

Any cloudiness left on the blade or guard can be cleaned up with alcohol if the epoxy isn't cured or with acetone later after curing. Not a big deal.
 
Marc, Will's was another WIP I referenced during this, definitely another classic with a few different ways of doing things that helped.

I used my disc grinder on the second go around when re-cutting in the shoulders, then an EDM stone with a softened edge to help clean up the radii on them. I was gong to use my disc the first time, but unfortunately this is one place that the KMG work rest gets in the way, or at least its mount that attaches directly to the motor face. I ended up using the top of the disc, but it's a pain trying to hold it square to the disc while bending down to get a view of what going on between the shoulder and disc face.


Kuraki, thanks for the tip. I checked and checked and checked again with my mic that all four corners of the ricasso were the same thickness to make sure it was flat and parallel. Turns out my file guide slipped the first time I cut them in which caused me to think certain things wouldn't work again on the new guard that I had tried on the first guard. I started getting some things mixed up since I've been taking breaks working on this knife for a while now, but thankfully It fit up properly last night.

Anybody happen to know if any place or anybody is still selling those guard "pushing" jigs that bolt to the tang? I saw one at USA Knifemaker a few years ago but looked again recently and couldn't find it anymore. I see if I can find a picture of one.

~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
Here is one that apparently David Roeder made himself, but I remember seeing them being offered at USA knifemaker.

It anchors to the tang using the center bolt, and then the other two bolts push the metal plate againt the back of the guard and force it on there. I would much prefer doing it this way than using a hammer, as I have already mushroomed the tang shoulders a few times on this one knife by trying t close the final gap.

9ed587bee0210c0db9d7350aee059892.jpg



~Paul
My Youtube Channel

... (It's been a few years since my last upload)
 
i4Marc said:
A couple of thoughts,

A lot of people know about Nick's WIP which is a great resource but Will Morrison's WIP is also excellent. If you haven't read it, find the time. Check page three for guard fit up.

https://www.bladeforums.com/threads/introduction-and-a-wip.1082411/

JB Weld, like other epoxies, works as a moisture seal under the guard. It's pretty strong too and takes about 600˚ to break it loose if you screw up. Don't ask me how I know. It should not be a replacement for a tightly fit guard as you know. With the blade in a vise and tang up I put a ring of the JB Weld around the tang just above the ricasso. Then I fill the guard opening with the epoxy and carefully slide it down the tang trying to avoid the tang dragging epoxy out of the guard slot as much as possible. As the tang drags epoxy out of the hole it will be running over more epoxy from the ricasso side. I set the guard in place with a 2.5lb drilling hammer and a length of PVC pipe. Do not hammer so hard that you are mushrooming parts. I use a larger hammer because it gives me a larger hammer face and the mass allows me to use a lighter swing, if that makes sense. The pipe has been warmed at one end with a heat gun and clamped in a vice enough to squash it into an appropriately sized oval. Leave it in the vice until it cools then touch up the end nice and flat on your 2x72. The PVC is very tough and will withstand a lot of hammering. Once the guard is seated you can clean up the guard face and ricasso with cotton swabs and alcohol. Don't over wet the swab. You don't want alcohol wicking up into the joint dissolving the epoxy. You just want to wipe the excess epoxy away with dry swabs then do final clean up with damp swabs. Keep checking for squeeze out for about 10 minutes and wipe clean.

As far as fit up goes, one tip I got from Nick was to use the belt sander to true up the shoulders. The carbide-faced file guide works great for this application. I have been frustrated in the past trying to square up the shoulders with a file, stones, etc. I'd check the flatness with a fresh razor blade and I couldn't feel any variation from the file guide but somehow it just wasn't perfect. When I started using the file guide against the platen on the belt sander it just worked better. If you have variable speed turn it way down and use something like a 400 grit belt.

The other thing is to get yourself a set of radius gauges. You can't see how the guard and shoulder radii are mating but by checking both individually with a gauge you can get a pretty good idea.
Click to expand...
Awesome advice marc exactly what I was looking for. I have both nicks and wills WIP saved as extra tabs on my phone for quick reference. Probably 2 of the best ones ive ever read.
I really need to invest in a 9in disc sander. And just wire it up to my kbac 27d
 
I hot fit my guards. Basically, drill a pilot hole, heat em up and drift them to 95% fit. The last 1/16 is cold pressed. I do use JB weld or G-Flex for the final press, though it is redundant.
 
Rick Marchand said:
I hot fit my guards. Basically, drill a pilot hole, heat em up and drift them to 95% fit. The last 1/16 is cold pressed. I do use JB weld or G-Flex for the final press, though it is redundant.
Click to expand...

I'm curious about hot fitting and the order of operations. What level of completion is your blade when you do this? When you say the last 16th is cold pressed, do you mean you hot press up to within a 16th of the shoulders, and then cold, or are you hot fitting directly up to the shoulder and then squeezing the width/peening the face? How do you maintain perpendicularity between the face of the guard and the tang when the guard is malleable? If the blade is heat treated prior to fitting, do you use a wet rag or anything to prevent heat leaching into the blade? If it's before heat treat, do you quench the blade, finish the shoulders and then do the last 16th cold?

Sorry for all the questions I've just only ever seen hints of what goes into hot fitting a guard and enough to know that people do it, but not really how to avoid some of the issues that come with it.
 
All great questions.... no.


Ha!... I'll do a video at some point or start a thread with pics. But just so you know, you nailed just about every potential issue.

What hot fitting is mostly useful for is taking the bulk of the work away. If you forge and don't have a mill, hot fitting is great. Also, I have done "unplugged" demos where I fully forge just about everything and hot fit to finish. You can get away with it for that style. Forged finishes close gaps nicely.
 
I look forward to a video, the advantages are why I'm interested, seems with practice it could be a big time saver, but the process stability is low (if I'm just winging it) compared to milling.

Also would likely be nice for guards forged to shape to maintain pattern flow that don't have easy work holding solutions on the mill.
 
Yup... it is good in some ways but limited in others. I have made drifts in several tapering sizes. The actual tang of the knife sees only one short heat. It is clamped to the shoulders in a vice with copper or aluminum guards.

I got inspired when my wife bought me several antique Japanese Tsuba. Upon researching them, I now know that they were most likely cut and filed to fit but at the time, I assumed they were hot fitted. See... ignorance is the mother of invention... maybe.
 
Funny you bring that up, the main reason that sparked my interest was thinking about the possibility of hot fitting a habaki of untraditional material given the shape/size of the hole making machining unlikely and the material I'm wanting to use, traditional cold forming unlikely.

Making a drift was going to be my first step, but after that I started thinking myself in circles on how to see it through to final fitting.
 
Rick, are you using a "dummy" tang the same size and shape of the actual tang to do the bulk of the drifting as is often seen in sword making?

I also am very interested in seeing your process. :thumbsup:

~Paul
My Youtube Channel

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