JB Weld vs. Silver Solder

J. Neilson

J. Neilson

Joined
Feb 6, 2001
Messages
3,621
I'm sure this topic has probably been beaten to death but, I've missed them so here goes. I've used JB weld on my damascus knives to prevent ruining the etch from clean up. I've just started doing hand rubbed finishes (thanks for the tutorial Bruce) and I really liked the finish better before I had to clean up my solder joint. The finish looked cleaner before I had to work around the guard. So, I'm thinking of JB Welding all my guards even though I like (and like to do) solder joints. Any thought, tips or opinions?

Rene also was telling me about a product from Brownell's like JB but you heat it? Anyone have info on this? Strength comparison, use, etc?
 
I too am very interested to know if in the long run there are any problems with useing JB Weld....

I used to solder the brass guards,,,then one of you guys talked about bonding them on with JB Weld, and I have used the J B from then on..

Now, there is another question I would like to add at this point...

QUESTION:...In the website where I learned how to place a guard with J B Weld, the guy just used the normal JB weld,,,however due to the long set time,,I have switched to a glue called J B Quick...

This type of J B Weld has a 4 min set time,,so I can do a guard, then turn rightr around and start work on the handle.....

But will the J B Quick last just as long as normal J B Weld?
 
I know there are many pro's, and con's, and everyone has their preferences. But no matter what anyone likes, or dislikes, JB Weld is not as strong as silver solder.

If the knife is used, sooner or later it's gonna get dropped. If it hits just right, the JB Weld is going to fail.

Not even going to bring up the possibility of the knife being thrown. :eek: ;) :D
 
I use a mill to make the guard and relieve the back side using a 1/4" end mill. Actual guard surface against the blade is about .100 thickness. After getting a really tight fit I use JB weld to seal the guard to the blade and clean up the exterior using WD-40. After that has a chance to set I backfill the relieved area w/ accraglas at the same time I put the handle on also using accraglas. I had to take a handle off last week because of a drill bit wandering while drilling for a pin (always use a sharp bit!!) and had to beat the cured accra glas off the tang w/ a hammer to the point I started to just throw the blade away and start over but it finally came off. After beating that handle accraglas off I don't worry about the guard at all! After all the abuse there was no sign of either the JB Weld or the Accraglas cracking on the guard.
 
It is not intended as a filler per se to fill any gaps which shouldn't be there anyway. The purpose of using JB Weld or silver solder for that matter is not necessarily a matter of strength. Most hidden tang blades have guards that are press fit. The purpose of either is to seal the joint to keep the nasties out. Now, having stated all that, I honestly have no idea if JB Weld will deteriorate over the long haul. That remains to be seen.

I wouldn't use JB Weld to try to epoxy a tang nut on a butt cap. I may question that as a matter of needing strength. The high temp solder is the way to go there. I used to make a thong hole/nut thingy but Sabre demonstrated the strength of the high temp stuff at one time and I haven't looked back since.

Craig
 
Jay, I use JB Weld for bolsters but silver solder guards, even though I have the clean up to do (BTW, I cleaned up that damascus you saw).

I dove tail my bolsters with a dove tail mill so the JB has a pocket to lock into and flow through a tang hole into the next bolster's dove tail. John Andrews has convinced me to start using Brownell's glass bedding compound instead and will be getting some of that for the next bolster knife.

I have not been able so far to get silver solder to flow under the bolsters because of the tightness but the same dove tail procedure should work for that so long as I solder from the back side.

RL
 
Originally posted by rlinger

I have not been able so far to get silver solder to flow under the bolsters because of the tightness but the same dove tail procedure should work for that so long as I solder from the back side.

RL
Click to expand...


Soldering bolsters is not a good idea. It's almost impossible to neutralize the flux trapped under it.
It's a case of flux rot waiting to happen.
 
I can't state an opinion on JB Weld holding up on knives, but I can on some other situations. One example of where I have seen this product hold up to something that was almost unbelievable was where a person repaired an exhaust manifold on a large air cooled motor with JB Weld. He beveled the crack and filled it in with JB like you would if you were brazing it. I know that this motor saw a lot of use and the manifold was still on there 3 years later when he swapped the motor for a larger on. I have seen this product used on some other instances where it lasted for a long time and survived high temperatures and vibration. As long as the surface is properly prepared, I don't think you have to worry about this product "turning loose".
 
I'm the guy with the JB Weld tutorial. I'm the guy who really wishes he'd never put the tutorial up on the net. Why? Because I'm the guy who has been flooded with email for three or four years about the bonding strength, tensile strength, shear strength, flex strength, etc, etc. Folks want to know will it hold the guard? Will it hold my bolsters? Will it hold [insert whatever here]. I'm the guy who keeps saying, it's not to hold the guard. It is to seal the joint.

Also, on more than one occasion I've felt like I had to defend my usage of the product on various forums, as well as explain the useage and the purpose. Rather than trying to re-write what I've written over and over on other forums, I've decided to compile a couple of them and post them here. I will tell you how I came to use JB Weld, and everything I know about JB Weld.
 
About JB Weld and Guards - Part 1

I'm quite sold on the JB Weld also. I learned the technique from Jerry Fisk circa 1996 and have been using it since. I don't know how many years Jerry had been using it before he taught me. I believe Jerry picked up the technique from Harvey Dean, and I don't know how many years Harvey had used it before sharing it with Jerry. I've never had any problems with it and neither has Jerry. We both still employ this technique. I assume that Harvey does as well.


I should mention that it's not the JB Kwik that I use though. I use the standard JB Weld. Here's the specs on each.

JB Kwik
Properties -- lbs/psi
-----------------------
Tensile Strength: 2100
Adhesion: 1800
Flex Strength: 7320
Tensile Lap Shear: 1040
Shrinkage: 0.0%
Resistant to 300º F

JB Kwik sets in 4 minutes and cures fully in 4 hours

JB Weld
Properties -- (lbs/psi)
------------------------
Tensile Strength: 3960
Adhesion: 1800
Flex Strength: 7320
Tensile Lap Shear: 1040
Shrinkage: 0.0%
Resistant to 500º F

JB Weld sets in 4-6 hours, and cures fully in 15-24 hours

The main difference in the two, other than the set time and curing time, is the tensile strength and resistance to heat.

####

Also worth mentioning is that (as stated in my tutorial) while JB Weld has tremendous bonding strength, the purpose is NOT to hold the guard on. That is done with a good fit. The guard stops on the back of the ricasso prevent the guard from moving forward, a good fitting, well bonded and pinned or bolted handle prevents the guard from moving backwards. A properly fitted guard slot (both in length and width) prevent the guard from moving up, down, side-to-side, or twisting.

The purpose of the JB Weld is to seal the joint. That is the same purpose of solder. If you are soldering guards for the primary purpose of holding them on or to hide small gaps, then your fit could use improvement. This is not to say that those who choose to solder are not getting a good fit. I just want everyone to understand that the purpose of both is to seal the joint from moisture and contaminants.

I was getting so many emails about the holding strength of JB Weld it was driving me nuts. I kept saying over and over, "It's not to hold it on , it's to seal the joint". When it finally came up to haunt me again in a thread on CKD many months ago, I decided okay dang it, let's see if the friggin' stuff will hold.

I fitted up a guard and sealed the joint with JB Weld. I let the thing cure over night. The next day made up a makeshift harness and slipped it on the guard.

guard_harness.jpg



Then I ran the makeshift harness through the a bowling ball bag with a 16 pound bowling ball inside, lifted up the works and started walking around the house with it. Here I am in the den.

guard_test.jpg


Not a scientific test, but now I can say, yes JB Weld does a great job of holding the guard. BUT, the purpose is not to hold the guard on. It is to seal the joint.
 
J. to prevent messing up your damascus etch, go ahead sand your blade to finish and solder your guard on, clean up the joint to finish and then coat what you don't want the acid to etch with finger nail polish. Then etch your blade. Thats the way I do all mine, and if its a damascus guard I just go ahead and etch it at the same time I etch the blade.

As for J-B weld, its pretty tough stuff, I use to use it some and to get a guard loose you did need a hammer, but, and this is just my opinion, I think a knifemaker should do the best job he can on any knife he plans on selling and to me that means soldering on the guards.

There's several ways to do every and any part of knifemaking, its up to the individual maker to use his own judgement on what he feels is the best, just don't settle on any one way, just because its a little easier.

Bill
 
About JB Weld and Guards - Part 2

I also hear things like using "glue" just doesn't cut it, and solder is one of the things that says "quality", and shows the skill of the maker. That has on occasion been followed up by the statement that "JB Weld is used by people who can't solder a good joint".

So here's one of my responses to that statements like these:

####

I disagree. A good fit is what say's "quality". A good solder joint will be "virtually" invisible. So will a good fit where the joint is sealed with JB Weld.

jamie_guard.jpg


But with JB Weld, close isn't good enough. If there is any gap at all it will show. Small gaps can be hidden with solder. Not so with JB Weld. It's either right or it's not, and there ain't no middle ground. The invisible JB Weld sealed joint on a $10,000 Dean or Fisk art knife screams "quality" and "skill".

JB Weld is not just a glue. It is a two part cold weld compound consisting if a liquid steel/epoxy resin, and a hardener. When mixed together in equal portions, a chemical reaction occurs that turns the mixture into a compound as hard and tough as steel -- and with similar properties.

Like steel, JB WELD can be formed, drilled, ground, tapped, machined, filed, sanded, etc. It's impervious to water, gasoline, chemicals, and acids. It is designed for safe, reliable, permanent repairs in engine compartments and heated environments up to 500º F.
 
About JB Weld and Guards - Part 3

For anyone who wants to hear other folks opinions, and some historical facts such as the use of pine tar and pitch at the joint of swords circa 1200 AD, check the long thread on Don Fogg's forums. Here's a link:

To solder or Not to solder?

I of course put my two cents worth in that one as well. By the way, the use of pine tar, pitch and similar substances on those early swords was for sealing the joint -- not for holding the guard on.

#####

On a hidden tang knife with shoulders on the back of the ricasso, the guard simply can not move forward. With a good fit on the slot the guard simply can not move up, down, sideways, or twist. When the guard is backed up by a handle which is secured by both 2 Ton epoxy, Acra-glas, etc. and Corby bolts or pins, the guard simply can not move backwards. It "ain't goin' nowhere.
 
Heheehee, this thread kind of reminds me of the one on blade finishing last week. We each have our preference and often will go pretty far to prove it :)

Terry, I agree with you on the sealing issue, fwiw.

Mike, I agree with you on the flux rot under the bolsters issue, fwiw.

J, I agree with you about it probably being beaten to death, but that can be a good thing. Somebody might have missed it the last time around.
 
Mike, very good point about the flux. Being around soldering for many decades I understand and agree completely.

Terry, great info you are providing here. Thank you and I, in some ways, understand what you mean about the constant questioning. I have gotten some real head-shaking questions from people contacting me through my web site. It is amazing and seemingly never ending.

RL
 
Originally posted by primos
I'm the guy with the JB Weld tutorial............
Click to expand...


AH HA!!.........Now we know who to blame!!:eek: ;)

Just kidding Terry. BTW, I think you should be congratulated for the interest you stirred in this method, and I don't believe I've seen anyone here ever say anything derogatory about it.

I just happen to prefer silver solder. Perhaps when I'm old like you, I'll try the JB Weld. ;) :D
 
Geez, I shoulda known I'd be starting trouble with this one.

First off Terry, I'm glad you put the tutorial up. It has helped me many times. I also agree on the sealing factor. The entire knife is what holds the entire knife (hope that makes sense). Also, I am a great admirer of your work. I've got pictures out of Blade mag. of your knives on my shop wall, for inspiration. Been there for about 3 yrs. now. I also understand the defensive angle. It's like when I make a nice knife and use a corion throat and someone inevitably asks why I put toilet seat material on it.
:rolleyes:

I really wanted different opinions and I guess I'm gettin' em. Thanks to all.
 
I guess I'll through my .02 cents in, I'll say this about JB welding gaurds, it's harder to do than soldering.

I haven't moved fully into JB gaurds, but I'm heading there. But if I get a gaurd thats a little off(still doing gaurds with drill bit and files)I still use solder. Also depends on the material, I have a heck of a time soldering bronze, so I almost always use JB to seal it, event to the point of makeing a new gaurd because of one tomany file strokes.

From my own destructive testing I have compleat confidence in JB as a sealant.
 
I too, want to thank Terry for that tutorial. Since then I use it about 25% of the time for guards and silver solder the rest. Call me weird but I really like to see a uniform silver solder line on a knife.
 
Like I mentioned before, I use the JB for guards on damascus blades and silver solder straight steels (I'm gonna try the nail polish idea though Bill, thanks). I'll probably still do it this way but, I wanted to get some ideas and play around with it on a few knives. Hey, I'm still new at this. Only been making knives for, not even, three years. I really, also, probably need practice cleaning up a hand rubbed finish after soldering. Only done two 'rubbed finishes so far. Anyone want to share tips on this, too?
 
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