Hi all,

This is a blade in work. Made of chainsaw blade and air. The chain was forge welded into a billet. Streched and folded once. Apperently, I have cracks issue. I guess it's bad welds. For various reasons, I REALY want to salvage this blade.

I was thinking of filling the cracks with silver solder. What do you say? Did anyone try this?

I know that generaly, metal to be soldered/brazed, need to be clean. There is no way to clean oxidation from inside these cracks. Is that a deal breaker?

Any ideas or pointers?

(just a note - the cracks penetrate no more than half way through the blade's thickness)

Thanks,

They MUST be ground away!  Solder is NOT OKAY for this type use!  Whatever “various reasons” you have... put them aside and either grind these defects off or start anew!  You’ll be glad that you did.  

I just noticed... you have some serious cracks showing at the spine of the blade as well!  They are almost clear through!  This is not salvageable unless you can shorten the blade enough to clear away the defects!

I am sure its too late to close and reweld,  this is a major problem of jumping into the deep end, not enough experience to know a problem until it is too late. Sorry  Try grinding it out into a smaller blade

The bigger the knives I attempt, the smaller the blades I make.

Everybody else pretty much covered it. But if you insist on doing damascus, then maybe start with the simpler processes, like a stack of pieces, rather than something genuinly difficult to weld like a chain. 

I agree with the assessment of the blade of course, but I have a related question that's been bugging me for a while.  A number of times on Forged in Fire, the judges have talked about contestants addressing/fixing cracks in the blades.  Many times to my eyes that's not possible.  Cracks along the cutting edge that are visible on both sides of the bevel, for instance, to me are not something that can be repaired, and grinding past the cracks would (again to my eyes) result in a blade unsuitable for the challenges and/or no longer within the specified parameters.  Have I been missing something or are there suitable solutions other than grinding to "fix" the cracks in those blades?

3 hours ago, Buzzkill said:

I agree with the assessment of the blade of course, but I have a related question that's been bugging me for a while.  A number of times on Forged in Fire, the judges have talked about contestants addressing/fixing cracks in the blades.  Many times to my eyes that's not possible.  Cracks along the cutting edge that are visible on both sides of the bevel, for instance, to me are not something that can be repaired, and grinding past the cracks would (again to my eyes) result in a blade unsuitable for the challenges and/or no longer within the specified parameters.  Have I been missing something or are there suitable solutions other than grinding to "fix" the cracks in those blades?

I've wondered the same thing but I'm not holding the blade in my hand looking at in person. I have to assume I'm not seeing what they are.

Frosty The Lucky.

an experienced person may be able to re weld the gap, the inexperienced one is most likely dealing with more than the visible cracks, they may even open up more as they grind because with them, it is not just one bad weld also FIF is dealing with a challenge and a finite end point, all the blade has to do is get ti the testing and finish it.   They dont care about next week or funny shadow on the blade, if they can get the blade to pass the testing It  didnt fail here so would solder to get it to pass  it but never to sell

FIF is not real knife making, it is a game show

21 hours ago, JHCC said:

The bigger the knives I attempt, the smaller the blades I make.

Most of my letter openers start as broadswords.

3 hours ago, Steve Sells said:

FIF is not real knife making, it is a game show

Understood.  Thanks for the response.  I was just wondering if I was missing some other valid way to "fix" cracks.  The only thing that ever made sense to me was grinding past the flaw, and even then if there were multiple cracks to me the blade is always suspect and should probably not go out into the world for real use.

The only cracks I deal with are in the tang and then I arc weld the heck out of it, reheat treat  and use it as a personal beater blade.