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Re: A Good Example

Posted: Fri Jun 03, 2011 11:00 am
by Elvis
Good questions, but the JB Weld just isn't strong enough and would chip apart the first time the blade was opened. As for the Aluma Weld, I have some and although it works great with aluminum, it won't stick to steel and since it's softer, I'd worry about it wearing out too fast. As far as the Rough Riders, I've worked on a couple for a friend who only has use of one hand and sends me his knives to have the action weakened. The brass is too soft and plyable, like they aren't really made to be worked on. Except for his case, I don't work on them as I consider them throw-aways (let the hate mail begin). ::mdm::

Re: A Good Example

Posted: Fri Jun 03, 2011 12:57 pm
by muskrat man
looking good Bob.

I've tried JB weld and Bob is right, it peels right off the tang when the action is worked for the first time. I have used silver solder to make tang repairs but even it will wear as it is softer than the backspring steel. Weld is about the only way to go. Now, that said. I have a theory, as I have yet to actually try it but I see no reason it wouldn't work. Cut the tang down a lot and dovetail in a larger piece of steel and solder it in place (like the old Robeson mastercraft series with the bronze tang inserts) and shape to fit. I see no reason why it wouldn't work but it would be very time consuming, having someone lay a bead of weld on the worn areas would be much more realistic.

One thing I am curious about though is the temper, how is it affected by the weld? I worked on one switchblade that a guy welded in a chip in the tang that was preventing it from locking open. When I worked it down to fit it was VERY hard, like freshly quenched steel that hadn't even been drawn back. I always wondered if he quenched it in something immediately after completing the weld. The metal was all down to a bare finish almost like a bead blast look. maybe he dunked it in a pickling solution to remove the scale after the weld was complete?

Re: A Good Example

Posted: Fri Jun 03, 2011 4:02 pm
by Elvis
I received a PM asking what rods my welding guy uses and I had to plead ignorance. He asks me if he's welding stainless or carbon steel and takes it from there. The welds don't seem that much harder than the rest of the tang, but without proper testing, it's hard to know for sure. In this case since the tang and backspring were both welded I think it's safe to assume they now have the same hardness in that spot so uneven wear shouldn't be a factor.

As for your welding guy Kaleb, the person who sent me the PM mentioned certain rods that produce a welding bead that is around RC 58. Since modern (factory) blade heat treating methods leave the tang a tad softer than the blade area, I'm wondering if 58 would be too hard and begin to wear on the backspring. I'd also like to mention that he is always careful to clamp the blade or backspring in a vise with only the part that needs attention sticking up. This allows the vise to act as a heat-sink helping to prevent heat transfer to the blade area so we don't lose temper.

This method has worked well for me and is the only way I've found to correct this problem short of using new parts which often just aren't available on a lot of the older knives. Your biggest hurdle in using this method will most likely be finding a welder with the talent and patience to do it. I highly recommend bribery with folding cutlery. :mrgreen:

Edited to add that the knife has been reassembled and just looks like the last pictures of it with the pins peined. End of lesson I suppose, but I'll be here for questions and I hope this has been helpful to someone.

Re: A Good Example

Posted: Fri Jul 01, 2011 1:46 pm
by vieu101
Looking good Elvis...you gunna post pictures of the knife I sent you LOLOLOLOLOLO

Re: A Good Example

Posted: Mon Aug 22, 2011 1:30 pm
by Elvis
vieu101 wrote:Looking good Elvis...you gunna post pictures of the knife I sent you LOLOLOLOLOLO
Yours had the same problem, but works great now. Although your knife was a bit newer, the main blade had lost all snap. All it takes is a loose hinge or "pivot" pin and the uneven wear will start. "Keep 'em tight and oiled" would make a good motto for this situation, don't ya think?

Re: A Good Example

Posted: Mon May 20, 2013 6:13 pm
by 0078
Bob I'm going to give this a try did you mig, tig, or braze I'm try it on some junk knifes first. Ill keep you posted, thanks for the thread. Greg

Re: A Good Example

Posted: Mon May 20, 2013 8:04 pm
by Elvis
0078 wrote:Bob I'm going to give this a try did you mig, tig, or braze I'm try it on some junk knifes first. Ill keep you posted, thanks for the thread. Greg
TIG.

Re: A Good Example

Posted: Fri May 24, 2013 7:52 pm
by orvet
Bob,
If I recall correctly you posted some work-in-progress pics of the TIG welding on one of the first blades you did. Do you recall where that post is?

I have recently discovered a guy in my town who is willing to try it.
I just wanted to check how you did it.

Thanks,
Dale

Re: A Good Example

Posted: Fri May 24, 2013 8:33 pm
by Elvis
I think the only ones I've posted are at the start of this thread Dale.

Re: A Good Example

Posted: Mon May 27, 2013 12:49 am
by orvet
Thanks Bob.
I should have looked back through the thread. ::doh::

The pictures showed me what I was looking for.
Thanks again.

Re: A Good Example

Posted: Tue Feb 25, 2014 1:13 am
by btrwtr
Elvis wrote:
jerryd6818 wrote:Are you going to weld and re-drill the pivot hole or will you just drill it slightly oversize to get rid of the out of round and use a larger pin?

Steady as she goes on this one. ::pray::
Steady as she goes is right. First I'll trace out the exact shape and size of the remaining intact piece of tang to give me a guide as I regrind and normally there is no problem with the hole. TIG welding uses a rod (in this case) that is about 1/16" and the guy that does my welding can add the needed metal without filling the hole. Its what he does for a living and he's gotten very good at it. My biggest concerns will likely be grinding the blade back to 1 or 2 thousandths less than the width of the backspring and making sure the backspring grinding is as seamless as possible. After that, it should be a straight-forward reassembly since we're using the original handle material.

If the hole were to see some added metal, I'd take a small Dremel attachment (after grinding to the correct width) and try to bring the hole back to match the other blade in the knife. I'm not a fan of enlarging the pin size except as a last resort. It is a good option that is nice to have as a fall-back should problems arise, but I try to save it if I can.
Have you or your welder ever used a heat absorption paste to keep the heat generated from the welding process from ruining the blade temper?

Re: A Good Example

Posted: Tue Feb 25, 2014 1:38 am
by Elvis
btrwtr wrote:Have you or your welder ever used a heat absorption paste to keep the heat generated from the welding process from ruining the blade temper?
No. He clamps the piece in a large vise (jaws are each abour 2"x10") so that only the tang end or the tip of the backspring are showing. The vise seems to work well as a heat-sink for this purpose.

Re: A Good Example

Posted: Wed Mar 05, 2014 2:32 pm
by btrwtr
I've always referred to the small tabs of metal that develop as "ears".
Not sure if there is another term but that's what they look like to me so that is what I call them. Any other terms you use or suggestions to describe?

Wayne

Re: A Good Example

Posted: Wed Mar 05, 2014 3:51 pm
by Elvis
btrwtr wrote:I've always referred to the small tabs of metal that develop as "ears".
Not sure if there is another term but that's what they look like to me so that is what I call them. Any other terms you use or suggestions to describe?

Wayne
I never thought about giving them a name, but "ears" is probably as fitting as any. I don't recall if I mentioned this or not, but I lay the blade with the "ear' down and trace the outline to use as a guide for regrinding after the welding is done.

Re: A Good Example

Posted: Sun Nov 02, 2014 5:10 pm
by Huck Finn
:: A little knowledge is a dangerous thing: mass confusion; I'm a rocket scientest, Merry-go-rounds make me me feel nausea.

Re: A Good Example

Posted: Wed Nov 02, 2016 3:52 am
by GClaxon
Excellent post!! I have blade tangs welded all the time for customers at my shop. The only way to save a knife when replacement blades can't be found, especially harder to find brands.

Re: A Good Example

Posted: Tue Jul 25, 2023 12:08 pm
by millern
Great photos! Similarly,I have used a 90amp Harbor Freight wire feed welder to add a tiny spot of material to the tang of a leverlock switchblade to close the worn sear hole. I then re- file the hole “open” just enough to catch the sear. This can address the problem of worn switchblade knives when the tip of the blade “peeks” out of the handle when closed. Using a vice grip or bench vise seems to provide an adequate heat sink during the spot-welding. I have notice very little tang discoloration from heat.

Re: A Good Example

Posted: Tue Jul 25, 2023 9:55 pm
by Elvis
Millern,
Usually that slight discoloration can be buffed out if you have a buffer and some buffing rouge.

Re: A Good Example

Posted: Tue Jul 25, 2023 11:51 pm
by 1967redrider
This is a great old thread. How much fidgeting do you have to do to make a blade look like that. ::shrug::