How tough should a forge weld be - knife tang

[Stefflus]

The last year or so, I've attended a couple of classes, and at one occation forged with a very skilled "freestyle" smith (he prefers only hammer and anvil). He could make a knife in a couple of minutes, and it was flawless.

Even so, most of my forging has been experimenting on my own. With slow but steady improvement.

 

The latest forge weld-related improvements include:

-Going charcoal, thus removing the variable that comes from me not knowing if the coal is good enough and me not being good enough tending the fire.

-Making the hearth deeper.

-"packing", that is fluxing and going to almost welding temperature and so doing an initial cleanup. Also the laminates come closer prior to the weld itself.

 

So now it looks like I can make a quite consistent weld.

But when I draw out a hidden tang on a knife, it almost always fails. My suspicion is that I'm not forging squarely enough, so when I see it starts to diamond and try to straighten it, it fails.

So now I'm back to forging nails, practicing square.

 

my question: -Should a welded tang withstand squaring up from a slight diamond, or would the shear forces always make the weld fail? Is the weld simply not good enough?

[jmccustomknives]

Without seeing exactly what's going on here's some things to look at.  First, what have you welded together?  I've found that some combinations are more prone to shearing than other.  Second, work it hot.  Quit before it goes to the orange color range.  Use lighter hammers. 

[Steve Sells]

I rarely use patternweld for the tang I forge weld mild steel onto that area. also I prefer large tanges for strength.  I admit that with a hidden tangs small mass it may be easier to use the existing PW metals,   So take it slow and work at welding temp.  Also redeuce how much you reduce the cross section of the material will help.  making massive changes to the welds will have more stress than doing small redustions at a time. and taking more heats to do it allows tthe steel to relax a bit between our hammer  attacks.

[Stefflus]

Thanks alot, that was most helpful :)

 

jmcustomknives: It is pretty much the same with: rasp/file sandwiched in mild, UHB15 or UHB20 in mild (these are very low alloy carbon steels with .70 and 1 % C)

[the branch]

Have had similar problems myself. The tang ended up more of a twisted braid than a solid piece. For me it worked to just use a higher temp (welding) and take it slow. Maybe use 5 more heats than what you normally do, It may cost you more coal and time, but in the end its worth it. 

 

Where in Norway are you from btw?

[Stefflus]

I'm from Helgeland, living in Telemark at the time (school)

[the branch]

I'm from Helgeland, living in Telemark at the time (school)

A achso! Rogaland here. Remember you from the Stabburlås thread. Did you find out how it was done? :P