View Full Version : New Cutting edge required
06-18-2009, 04:30 PM
I just picked up a mini-excavator with a worn out dozer blade on it. It is worn out right down to the frog. I'm planning to replace or repair the cutting edge one of these days, and have been keeping my eyes open for some suitable material.
Question: has anyone done this type of repair? What would you recommend as to the type of steel to use. My neighbour said to cut a flange off a rail, or look for a used grader blade. I've had success using old leaf springs for rebuilding the "flat" part of a bucket on a front end loader, but never tried to repair the "vertical" like this one.
Any ideas would be most welcome.
Ive done a couple edges on buckets and we used AR400 plate, AR200(AR Medium) will work too but won't last as long as the 400
06-18-2009, 08:19 PM
AR plate seems to be pretty standard.
Dunno about mini-excavators, but for snow plows, there are several companies that sell replacement edges made of AR. Usually less than $100. Normally they bolt on. If you can't find an edge especially for your blade, you could buy a standard edge, trim it to length, and weld it on.
Or, weld on a mild steel backer with holes to accept a bolt-on wear edge.
My neighbour said to cut a flange off a rail, or look for a used grader blade.
That's my first thought. Worn bars from a big machine could make a couple for yours. Are you near a good scrap yard? Or maybe visit excavators in your area.
06-19-2009, 06:49 AM
my local government shop (county here in wisconsin) changes blades every year. they come and borrow my air hammer to blow the bolts back out. i got a 8 footer off the grader a few y ears ago. just for asking.
06-19-2009, 08:34 AM
Errol , used bolt on cutting edges from graders or dozers will work but I have seen the welds crack over time . If you have a heavy equipment dealer near you could get the correct size and type of material by taking the the model number of the excavator in and seeing if they can order you one . I have bought a couple of them from a local dealer , one was a stock bolt on and the other was a weldable edge from a piece of equipment they sell . They will also order custom cut AR400 plate edges . Their prices have been competitive with ordering off the internet . JMTC , Dan
06-19-2009, 10:48 AM
Thank you all for your help and turning me in the right direction. I certainly wanted something with abrasion resistance so looks like AR 400 is what i am looking for.
Good idea to ask for availability at the excavator dealer. That is what I will be doing next week. Using old grader blade is also appealing, but I'm not confident I would have success at welding thick grader blade material onto the existing frog.
The original cutting edge (or what's left of it) appears only 7/16 or 1/2 inch thickness, and the frog looks like is only 3/6 or 1/4" material. I'll keep you posted on how it goes.
06-19-2009, 06:47 PM
I would try your local farm supply, they likely have lighter edges more suited to your needs for tractor blades. Not sure now you have purchased it how much use the dozer portion of the excavator you'll need.......only you can answer that, trenching requires lots of use, digging ponds not as much.
Grader blades generally have the bolt holes offset for one usage, bulldozers are centered and can be flipped around, both are bolt on. I was fortunate enough to pick up some brand new grader cutting edges from the municipal district as they had previous new stock and switched grader brands and the new pattern didn't cross over........I'm building a 12' grader blade as a project but it's currently taking a haitus........LOL
AR400 is generally used for the plate and skins, the cutting edges are harder.
06-19-2009, 11:04 PM
Hey Errol! How's it goin?
Yep...for a home use machine...get an old grader blade.
Or a cutting edge that is cut off a bigger bucket etc.
OR...go to a place like Wilkinson Steel and see if they have any narrow strips of T&Q 425 or T&Q 500. I work with this stuff all the time and can vouch for its toughness.
OR...go to a bolt house or whatever will carry smallish things like that...often they will stock cutting edges.
They always have an older one that won;t fit or whatever... I got my cutting edge from an outfit like that. Not much money either..
07-02-2009, 02:39 PM
Russ, good to hear from ya. Going good here. Last week, I made progress on my project. I scrounged around town, and found a piece of 1/2 x 3 1/2" AR plate for $70.
Now I have hauled the excavator back home. My plan is to (next week)torch off the sliver of old blade and then weld on the new AR.
This will be fun welding. Not often I can "twist the throttle" on the welder, since most of my welding jobs are thin material, spending most of my welding time worrying about not blowing through.
Will keep all of you posted.
07-02-2009, 07:56 PM
Errol...don't put that edge on til I can have alook at a pic of that bucket...can prolly give you some tips on gettin more preformance out of your bucket...
07-11-2009, 01:53 PM
I am back in town and managed to weld on that new cutting edge
Russ, I sure could have used your advice on the repair of the bucket, too bad I already patched it up before I got your offer of help. When I got the machine, the bucket sides were worn right out, and one side was broken away from the outside ripper tooth. Here is the before picture, I started by torching out the bad sections......
Then I welded in some new 3/8 plate, put on some Stoody hard surfacing here and there, then rebuilt the tooth frogs, then popped on some brand new teeth. The bucket works pretty well, but the bottom is caving, so I'm having to be careful not to "pry" against the bottom.... will have to replace the entire bottom come winter time.
Russ, any ideas you can give me to improve my bucket performance would be appreciated. I've been using my home made backhoe and bucket for the past 20 years, and now with this upgraded digging machine, I realize bucket shape is important.
07-11-2009, 06:22 PM
Errol, is that a Nissan undercarrige, i've just welded the underside of the two blade arms on mine and it looks familiar, it if fun blasting away with big sticks for a change, blade repair looks good to go, i wear mine driving backwards!
07-12-2009, 07:27 AM
Errol...I like your blade repair...I'd crosshatch with Stoody on the corners.
You bucket looks fine too...I forgot it was a toothed bucket. Not a lot you can change on those.
I put wear strips across the bottom. Just 3/8"X2" mild steel with about an equal amount of space between them (2").
Makes the bottom of the bucket last a lot longer. The spaces between traps dirt so you are using dirt to sheild the bucket bottom.
Let the ends of the wear strips stick out about 3/4" on each side...it helps with wear on the side edge also.
07-12-2009, 11:50 AM
Boslab, the excavator is a Yanmar 6 ton. The arms are 1 x 7. The old blade was worn right down into the frog so lucky I was able to repair so easily. And thanks to members in this forum who steered me to AR plate.
Ya, Torker, I ran Stoody on the cutting edge and up the ends, but your idea of cross hatch on the corners is good, I've seen that on bulldozer blades. I guess I was a little cheap on the Stoody, that stuff is pricey. I used Can Am for a couple years, but couldn't find a good supply, so now using Eagle Alloys 606, a lot cheaper, and rods are all position and easy to light compared to Stoody.
The original wear strips on the bottom went longtitudinally. And my last bucket on my little backhoe was the same. I really don't know what the difference in performance would be, since I'm not really a digging man.
But I've seen buckets done both ways, and this time I'll go laterally as per your suggestion. Makes sense to me. Would give the bottom of the bucket more rigidity thats for sure.
07-12-2009, 04:20 PM
Errol...if the strips go from front to back they won't hold dirt...that's the idea...to get the dirt hard packed in there to extend the bucket life.
It does cut down on power a bit til you have the strips packed...you can feel the bottom of the bucket bite pretty hard if you have the angle wrong...