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How do you seasoned pros weld a .5" rond bar to the end of a .25" knife blank?
- Thread starter Ome108
- Start date
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- Dec 4, 2001
- Messages
- 3,824
Never added a 1/2" to a 1/4" blade tang. I have added some 3/8" tang extensions.
First, don't weld, braze. Namely silver braze, though there's no reason regular bronze brazing won't work. Silver brazing doesn't cause grain growth like welding does. you weld it and don't do a couple-three normalizing cycles you going to end up with sugar sized grain in the joint that will cause it break very very easily. It can be done and has been done, but it's way more trouble than it's worth. Much simpler and easier to silver braze. Not to mention you can silver braze with a Mapp gas torch and a bit of silver brazing wire and some borax for flux.
Best way I've found is to grind about 1/2" or so of the end of the tang to a tapered wedge, and cut and grind/file a notch in the extension you'll be using. The joint should be fairly tight, but not air tight like a guard fitting. Heat it up, protect the guard and blade from heat with a wet rag, add a little flux on the rising heat and braze together. You want it just hot enough to flow the silver braze, not over heat the steel. Hard to explain, not real hard to do. After brazing let it cool down slowly and do a couple heats to a dull red in the joint and let air cool. You'll bend the steel and break it before the silver braze lets go if you did it rite. This is if it's a non air harding steel like 1084 or even 5160 or 52100(though they will air harden somewhat), not some of the higher alloy stainless, though it should work with them, just haven't tried it and figured out how to spot temper the joint.
While not quite as easy as sticking an arc welder to it, much safer for the blade integrity and longevity.
I've done it with a mapp gas torch, but it's a lot easier with a fine pencil tip on an oxy/propane or oxy/acetylene rig. Just make sure to keep the blade and guard cool during the cool down and brazing.
First, don't weld, braze. Namely silver braze, though there's no reason regular bronze brazing won't work. Silver brazing doesn't cause grain growth like welding does. you weld it and don't do a couple-three normalizing cycles you going to end up with sugar sized grain in the joint that will cause it break very very easily. It can be done and has been done, but it's way more trouble than it's worth. Much simpler and easier to silver braze. Not to mention you can silver braze with a Mapp gas torch and a bit of silver brazing wire and some borax for flux.
Best way I've found is to grind about 1/2" or so of the end of the tang to a tapered wedge, and cut and grind/file a notch in the extension you'll be using. The joint should be fairly tight, but not air tight like a guard fitting. Heat it up, protect the guard and blade from heat with a wet rag, add a little flux on the rising heat and braze together. You want it just hot enough to flow the silver braze, not over heat the steel. Hard to explain, not real hard to do. After brazing let it cool down slowly and do a couple heats to a dull red in the joint and let air cool. You'll bend the steel and break it before the silver braze lets go if you did it rite. This is if it's a non air harding steel like 1084 or even 5160 or 52100(though they will air harden somewhat), not some of the higher alloy stainless, though it should work with them, just haven't tried it and figured out how to spot temper the joint.
While not quite as easy as sticking an arc welder to it, much safer for the blade integrity and longevity.
I've done it with a mapp gas torch, but it's a lot easier with a fine pencil tip on an oxy/propane or oxy/acetylene rig. Just make sure to keep the blade and guard cool during the cool down and brazing.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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- Aug 20, 2004
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If you are talking about putting a rebar handle on for forging, just weld it on as is. Pretty doesn't matter as long as the weld is strong. The knife billet should have a little extra length to leave a short sacrificial piece to be cut off after the knife is shaped.
Last edited:
- Joined
- Dec 4, 2001
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Doh! Sorry I was thinking of a finished knife with a tang extension for a pommel cap or something, not a forging billet. Guess the 1/2" bar should have clued me in. If it's a forging billet you might pre-heat the billet a bit, but like Stacy said, it's sacrificial and will be cut off.
Normally what I do is just stick weld with 7018 rods, but anything like a mig or 6011 rods will do. Only time I've had issues with re-bar or such welded on as a handle is when doing damascus and after a couple of folds the bar where it's attached gets too thin and floppy.
Normally what I do is just stick weld with 7018 rods, but anything like a mig or 6011 rods will do. Only time I've had issues with re-bar or such welded on as a handle is when doing damascus and after a couple of folds the bar where it's attached gets too thin and floppy.
- Joined
- Feb 1, 2015
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3/32 size 7018 rod, approx 70 amps, DC electtode positive
Thank You , Stacy.
Is there a shaded goggle or safety glasses with side shields , to wear under my fixe lense hood, not AD.
I HAVE #5 shade uvex safety glasses, but I know that it is a different shade chart for welding as opoosed to forge work. These are for forge work, but will they help me not getting arc burned or do I need to purchase a different pair of goggles.
If so, what would you recomend for me to wear under the welding hood.
Thanks Stacy,
ome108
Is there a shaded goggle or safety glasses with side shields , to wear under my fixe lense hood, not AD.
I HAVE #5 shade uvex safety glasses, but I know that it is a different shade chart for welding as opoosed to forge work. These are for forge work, but will they help me not getting arc burned or do I need to purchase a different pair of goggles.
If so, what would you recomend for me to wear under the welding hood.
Thanks Stacy,
ome108
- Joined
- Dec 4, 2001
- Messages
- 3,824
Not sure any safety glasses are rated for arc welding, I just use my old welding hood with clear safety glasses under it. One of these days I might invest in an auto darking hood, then again probably not. The dark lenses flip up with a clear lens for grinding.