Rotary Cutter Blades

[kenmac]

My Rotary cutter blades take a beating.(hitting rocks & such) I weld my blades up & re- sharpen them .Does anyone else weld up their rotary cutter blades & resharpen them or do you just buy new ones ?

 

[slowrev]

I rework my blades as long as they will hold up. Have not had one fly apart or anything yet.
Ben

 

[3RRL]

I'm sure lots of guys weld them up, depending on how badly they're worn, and where the wear is. If the damage was nearer the shank, I would buy new ones so they do not fly apart. I welded a good sized gouge in mine and re-sharpened, like you did.

 

[slowrev]

I also weigh my blades to keep them pretty well in balance, I figure the better the balance the longer the cutter will last.
Ben

 

[Bird]

I've sharpened blades and I've replaced blades, but I've never done any welding on one. And like slowrev, after sharpening, I weighed them to make sure I had them as close to balanced as possible.

 

[kenmac]

Bird, When I'am cutting grass/ weeds It's hard to see the rocks but my cutter doesn't seem to have a hard time finding them. My blades get some good size nicks in them . I weld the bad places up with a 7018 rod & grind or sharpen back down so that they are like new again. I do0 this instead of buying new ones

 

[Bird]

Ken, I sure didn't intend to insinuate that there was anything wrong with doing that; only that I've never done it so I wouldn't know what the difference would be in cost, time, etc. I'm sure it's cheaper than buying new blades, though.

 

[kenmac]

And I didn't take it that way bird. I was just explaining to you why I had to weld the blades up & was just wondering if anyone else has done this.

 

[john_bud]

And I didn't take it that way bird. I was just telling you why I had to weld the blades up & was just wondering if anyone else has done this.

You need to maybe think about that welding again. The blades are tempered for a combination of toughness (so they don't shatter) and hardness (so they wear a long time). Welding can embrittle the metal and allow it to shatter and shoot parts everywhere at high speed. It's rare, but it does happen. My Woods cutter had the blades replaced for free as they were too hard and prone to break.

Happy Ho Ho's ...

jb

 

[kenmac]

the blades that were on my cutter appear to have had the cutting edge cut with a cutting torch . So, if they were hardened it would have been after they put the edge on the blade . I have welded harden metel b-4 & can usually tell by the way it welds it it is hardened.I could b wrong, but These blades seemed to weld just like any other metal.I hope they don't shatter fly apart.I don't allow anyone near when I'am using the cutter for safety.

 

[3RRL]

....... & was just wondering if anyone else has done this.

Yes, I have. See post #3 above. The blade had a crescent shaped chunk missing out of it about 1" from the tip. It was about 1" long and ½" deep. I welded it back up using 6011 rod. While re-sharpening and filing, I noticed the weld was slightly softer than the parent material. Most stress occurs between the parent material and the weld because of the heat and metal mixing there. I've had no problems except I expect it to wear faster than the rest of the blade.

And as I stated in the above post, I would be hesitant or not weld near the connecting end. Towards the tip and cutting edge there, IMO I think it's OK. It's a lot quicker, easier and less expensive than buying new and replacing. But if the damage was near the connecting end, I would buy new and replace.

 

[kenmac]

If it wears out quicker with the 6011 weld , next time a harder rod mabe 7018, etc,.that is what I used . I'll see how mine wear using this rod. Of, course it will b a while b-4 I have to cut. I should call & find out what cutter blades cost. Thanks for your response !

 

[john_bud]

Yes, I have. See post #3 above. The blade had a crescent shaped chunk missing out of it about 1" from the tip. It was about 1" long and ½" deep. I welded it back up using 6011 rod. While re-sharpening and filing, I noticed the weld was slightly softer than the parent material. Most stress occurs between the parent material and the weld because of the heat and metal mixing there. I've had no problems except I expect it to wear faster than the rest of the blade.

And as I stated in the above post, I would be hesitant or not weld near the connecting end. Towards the tip and cutting edge there, IMO I think it's OK. It's a lot quicker, easier and less expensive than buying new and replacing. But if the damage was near the connecting end, I would buy new and replace.

You're probably right Rob, welding the cutting edge is the safest place to weld. Maybe a hardface rod would be a good thing, if you want to weld and make it last longer.

I did find out that two things have made the blades last longer. 1) It has hit most of the rocks already and gotten rid of most of them. 2) I no longer sharpen then with an edge like a grass mower blade. Just a bevel and leave 1/8" of blunt edge. But, it is used to cut saplings, brush and such not grass.

Ken, I did have one blade break this year. 1/2 way between the bolt hole and the tip, where the blade bends down for clearance. I think it was about 5 lbs of sharpened steel flying off at 15,000 ftm or 170 miles and hour. There was no indication that it was in peril, the deck just started vibrating real bad. Shut it down and expected to see a blade spun to the inside and jambed, but found a stub instead. Puts the fear of God into you, that's for sure. The 50 bucks for a set of blades is cheap enough given the damage a loose one can cause.


Good Luck!
jb

 

[jinman]

Ken, I did have one blade break this year. 1/2 way between the bolt hole and the tip, where the blade bends down for clearance. I think it was about 5 lbs of sharpened steel flying off at 15,000 ftm or 170 miles and hour. There was no indication that it was in peril, the deck just started vibrating real bad. Shut it down and expected to see a blade spun to the inside and jambed, but found a stub instead. Puts the fear of God into you, that's for sure. The 50 bucks for a set of blades is cheap enough given the damage a loose one can cause.

John, I've never broken a blade, but when I bought my first KK I didn't check the blade tightness before I used it the first time. After mowing for about 3 hours, I was driving down a gravel road back to my house and heard an awful clanking. I looked back to see a blade lying in the road. The nut was nowhere to be found on the road or as I walked back on the path I had travelled. I think the nut came off and somehow the blade stayed on the bolt due to centrifugal force until I stopped the cutter. I also got a queasy feeling in my gut thinking of what could have happened if that blade had come flying out from under the cutter.

Edit: I've edited this several times because it was a long time ago and my memory is fuzzy. As I remember, the bolt was laying in the road with the blade and the threads were "wasted." I know I had to order a bolt kit and that was two bolts and nuts. I couldn't order just one. I still have one bolt and nut as a spare.

Moral of this story: CHECK THOSE BLADE BOLTS BEFORE USING A NEW CUTTER.

 

[Soundguy]

I've never welded a cutter blade.. but have deffinately hard faced milling teeth in a big pulvi-mixer machine that we have at work.

It uses about 90 teeth that are about 1/" thick, by 2" wide, and about 10" long. In sand they wear fast unless you put a few beads of hardface on them... same with the pockets that hold the teeth.. you have to weld up the pocket or it wears down real fast in sand..

Soundguy