OK, this discussion probably belongs in the heat treating sub-forum, and if so, I apologize, but it didn't look like there was a whole lot of traffic there.
Here's my question.
I have a 54" cut riding mower that uses 3 blades. Buying three blades from Sears will put you back $75 or more. To a person like me, who throws around quarters like manhole covers, this price is absurd.
I am a decent SMAW weldor and have the welder and rods and grinders and belt sanders etc etc, and I was thinking of cutting some small "strips" out of some old lawnmower blades and welding them in to replace the steel that has been worn, ground and eroded away, and then grinding on a new bevel and mowing grass.
Here are my concerns:
1. Are lawnmower blades (especially the edges) heat treated, and if so, will SMAW welding new metal in wipe out the temper? (I suspect not, judging from the obviously overheated grind jobs I've gotten from "pros" in the past, but if so...)
2. If so, how would one go about restoring the temper, if it's possible? Allow the weldment to fully cool, then heat the whole edge area until it's non-magnetic, then quench, then temper in an oven?
3. If so, what temperature(s) and techniques would I want to use? I'm sure I wouldn't want the entire blade to be too hard, lest it break and kill the neighborhood like a nail bomb...but I suspect the edge portion of the blade should be at least marginally hardened.
There are other issues that I'd want to discuss beyond this, but I'll throw this out there as a starter.
FWIW, I would be using 6010 or 6011 rod to do the weldment.
Thank you in advance for any replies. And please no "Just spend the stupid $75 and be done with it!" flames...I'm poor but have lots of rod and love to weld and am dying to learn about heat treating.
Best to all,
Jeff