Hey guys:
I thought of this post again when 2 weeks back one of the large tater sized rocks decided to GROW and on 2nd mow I caught it. The rock was 4 or 5" long and fat in middle & blunt on both ends.

well I found some of it and really did some damage to the OLD set of blades that was on the 54" mower. They were still on from last season (maybe 2 hrs mow time on the sharpening from last year & first cut of soft grass this year.) They were sharp enough to split the rock lengthwise !! (red& black granite type stone.) I found the top 1/3 set a few feet outside mower discharge... Other part wasn't anywhere to be found so I kept mowing farther out expecting to find it. Nope didn't see it anywhere & cut was pretty bad for still soft spring grass, so I went ahead and changed to new set of sharpened blades. Finished mowing the yard no problem but the 1st (old original set came w mower) was in bad shape. On to 3rd mow last week and yep found the other 2/3 chunk of rock about 40 YARDS (36 meters) away (yep with the blades as the grass grew up fast enough to cover it.)

(I bet the rock was 3lbs when it was original full sized.)
So I since I had not FIXED the first set or had time to stop and buy some more I decided to take a close look at the first (old set) of blades. 2 were bent pretty good and tips were all pretty trashed & one was mashed back better than 1/2" or so. humm (no pics of before :/ ) so I had Mig Welder out already when doing some exhaust work so what heck figured I would clean em up a bit with grinder and then weld up the damage.
Here is what I did and some after pics (cell was not handy and was in hurry to get back to mowing.)
Using a heavy copper bar (one end left over from OLD blown 600 amp fuse when I did industrial electrical work.) Clamped it to bottom of cleaned up blades which covered 4" of tip (damaged area well.)
I ran from 1 to 3 passes of beads down the blades to fill in all the damage and build out the blades back to "near original" shape.
Bottom side w copper bar the weld will not stick to it and it leaves flat surface to WELD against. This makes building up the area easier as seen in pics above & below is bottom of blade after welding this blade was least damaged of bunch & only single pass other two had 2 and 3 passes.
Then took them to the hard 4-1/2" grinder disk to clean them up.
After grinding I could see that two blades were warped and since I had the NEW set off I checked them & all 3 had some issues so a quick run thru the press to fix them.
The end result of the 3 blades after welding, sharpening straightening and ready for running.
So far they seem to be holding edge about as well as old blades did & if I have to do it over I will try some 7018 or hard-surfacing rod in the stick! I have mowed once with them & edge is not razor sharp so some of the weld tip has worn away & do admit it was done for time savings as only place to "RUN" and buy some is probably 45 min away. time took was about same but price was less

If/When I do buy new blades going for the Gators for sure & BTW still need to FIX the new blades which are not in the have to weld it up range but will need a good hard grinder to fix. all good enough for farm grass...
Mark