Rotary Mower blades sharpening

elmerinva · Jun 28, 2002

On my Land Pride rotary mower, the blades needed sharpening which was done OK. I noticed the ends were rounded so that the actual width of cut was reduced by several inches. Has anyone tried welding on to the blades to "square" them out? Or is this just not smart because of the heat/temper,etc. I have only 60 hours on this set of blades.

rancar · Jun 28, 2002

Elmer,

<font color=blue>I noticed the ends were rounded so that the actual width of cut was reduced by several inches.</font color=blue>

Wow....only 60 hours on the blades and you lost several inches. Is this normal??

<font color=blue>Has anyone tried welding on to the blades to "square" them out? Or is this just not smart because of the heat/temper,etc.</font color=blue>

I've never done this kind of welding but my sense is these blades, when manufactured new, are of high tempered steel. I don't believe welded ends will produce the strength you need to maintain effective cutting capability. You may also find these ends will snap when you hit the first rock or sappling.

Bob

Slamfire · Jun 28, 2002

While you could extend the length of the blades, how would you handle tha balance problem? Rotating equipment is pretty fussy about that.

elmerinva · Jun 28, 2002

rancar, i probably wasn't clear about the rounding. The corner of the square blade tip has been rounded so that the radius of the rounded corner is about an 1-1 1/2 inch. When mowing the speed of the blades flattens the grass and leaves a row of tufts. The welding would just restore the corner to square up the blade. the rounding occurs i guess from rocks, dirt, saplings, etc. i guessed the steel on the blades is mild steel since it would have to deal with severe shock loads. maybe new blades is the easiest way.

slamfire, the balance would be a problem but would have to be worked. After sharpening, i have the balance problem to deal with anyway which i do with moving shim washers on the blade bolts.

thanks for the replies

Anonymous Poster · Jun 28, 2002

I am putting new blades on my Woods M5 cutter...it's got to be 30 years old...I think I may be only the second owner (had it for 9 years). The blade kit from Woods, with shipping to the local dealer was only around $45. Probably cheaper, and less time consuming than sharpening if the current blades are real bad.

JerryG · Jun 28, 2002

M5 blades are inexpensive. That's about what I pay for mine. They aren't worth the work of sharpening them.

djradz · Jul 1, 2002

I just sharpen them, including the rounded edge, and call it good. If they get too bad, then replace. I've mowed for years with the tips rounded and as long as you can get some sharpness to them, still get satisfactory results.

patrickg · Jul 1, 2002

Gee, A few minutes grinding on the blades while risking having the mower fall on you vs $45. I am rapidly approaching (probably passed) the desperate need for sharpening. I think I will go the "in between" route that Bird or one of the other sages suggested. Buy a second set to use while sharpening and ballancing the first set which is not currently installed while using the other set. Swap back and forth as required. I like it.

A couple years ago about 15 miles south of me a very experienced user (in his 90's) was killed when the brush hog he was working under fell on him and crushed him. Learn from the mistakes of others, don't do this.

Regarding welding on blades: Lets hear from some of the professional welders on board. Can we burn a few "hard surfacing" rods along the leading edge and grind the correct shape back in? Would this work? Is it worth it? I have everything but the appropriate rod and the knowledge of how to properly use it.

Patrick

Anonymous Poster · Jul 1, 2002

Yes, it can be done, in fact I've built mine up a couple times.
NO, I'm not going to post the technique here cause it isn't something that should even be attempted by anyone who isn't fully versed in welding techniques. Mine did shatter a bowling ball the neighbor's kid threw into the tall grass, after being rebuilt, and there was no evidence of damage to the blade, but it sure shook me and the machine when contact was made.
By the way, it isn't a hard surphace process you want to use, how would you ever sharpen that?

patrickg · Jul 1, 2002

Franz, Is this one of those "if you have to ask, you won't understand the answer" things? Sharpening a hardened surface? Uh, use my diamond surfaced angle grinder wheel.

OK, don't give actual specifics of the technique, just mention the rod you use.

Just out!! The bowling ball test for brush hog blades and gearboxes.

Patrick