JB Weld for tool repair?
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I have a rusty, nasty drawknife which I would love to put to use. It needs new handles but first there is a crack in need of repair. The crack is right where the tang comes out of the side of the blade.
_____----------______ =====/_________======So have any of you brilliant woodworkers and tool enthusiasts tried JB-Weld on anything like this? It don’t matter if it’s ugly, I just don’t want the tang to come off.
- Debra J
I haven’t tried it but I would assume that stuff is strong enough for AT LEAST a temporary fix…certainly no harm in trying, imo.
When it comes to surgically sharp steel being pulled towards my legs and abdomen, I don’t want to trust JB Weld or anything else to hold the tang onto the blade. I think you should be very certain of what you are doing.
Derek Long
Denver, ColoradoIf I remember correctly JB weld is a polyester resin that is pretty brittle. It is usually an ugly gray color.
I would try epoxy, and mix in fine sawdust, flour or baby powder until it is the consistency of mayonnaise. Tape off the areas you don’t want to get epoxy on. Don’t use the 5 minute epoxy, it is too weak. The epoxy joint should be stronger than the wood. If you decide to replace the handles later, use a heat gun and the epoxy will soften enough to remove.
Mike, I believe that Debra was referring to a crack in the metal where the blade joins the tang.
Dave
If that is the case, then the tool should be relegated to the wall as a display. JB weld is way too brittle to use here as well as epoxy. The ultimate tensile strength of steel is 10 to 20 times higher than the best epoxy, 30mPa versus 500 to 900mPa.
It could be fixed by a good machine shop, but with heat treating the weld and clean up it would be better to spend the money on a good draw knife.
Thanks y’all. I didn’t know about how brittle the stuff is. I have no interest in self-injury!
- Debra J
Whoever the first guy was that responded should not be trusted. Glad you got better input from better sources.
Hello Debra,
I have no idea what JB weld is (I’m from Oz) but as a former metal worker it’s a simple repair with an arc welder (stick welder). Grind along the crack a little to hollow it out a bit then weld with a tool steel electrode or if unavailiable a stainless steel electrode. Don’t be tempted to grind the weld flat as thats where the strengh is. As the crack is where the tang and blade meet there is no need for any heat treatment as the heat won’t travel far enough to cause much grief, especialy if the operator just uses a series of tacks.
Cheers jcatI am glad, I read to the end. Sometimes I’d like more (ex)metal workers here, because there is a lot of guesswork in that area.
Dieter
Whoa Jcat! It depends on what the whole drawknife is made of and if its old enough to have a forge welded high carbon blade onto a low carbon steel body (including tangs). If it is a “one piece” forged high carbon steel body, then the tang area may need preheating – otherwise the crack in the tang may just go all the way through the cross section of the tang and break the tang off.
Firstly just use a file to establish whether the tang is hard (ish!) or soft. If it is soft and easily cut by the file then go ahead and weld. Otherwise don’t! Or at least don’t use it afterwards!
All the best,
MarkI have always found that jb weld eventually wears out.
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