Hard facing rod on mower blades

[m32825]

I read somewhere that the majority of the cutting takes place in the inch or so of blade near the tip. Maybe you only need to hard face the tip?

-- Carl

 

[Oil pan 4]

Found the work lead.
On the 1/2 inch thick 4 inch wide shredder blades I made 4 passes of 5/32 stoody 31 at 175 amps DCEP.
Then for the mower blade I did 1 pass on each side one of the old blades with 1/8 inch 110 amps with US forge hard face rod.
It will take a little while to wear the steel back to the hard face rod on both blades.
Guess I can start tomorrow.

 

[Oil pan 4]

I can post pictures just have to resize them so they are tiny.

This is what happens when a regular mower blade hits a terracotta chimney liner. This blade is in the scrap pile, not going back on the mower.

I ground it down a little. I think the welding rod may have ran so hot that the base metal and hard face rod mixed. I was actually able to grind it down with a flap disk.

Raw hard face weld.

 

[Oil pan 4]

Now that it's warmed up some I got to use my riding mower.
Over the course of about 2 days the blade wore back to the hard face rod. Now starts the true test.
The actual blade I hard faced looks almost identical to the one in the picture.
Last time I pulled the blades off to sharpen the test blade had worn back to the edges of the hard face bead.
The hard face bead appears to definitely be more wear resistant than the original metal. I have one hard face blade and a unmodified one. They appear to wear at the same rate as far as I can tell. One more long day of mowing will tell me for sure if the hard facing does anything.
The brush shredder is at the shop and they are ordering the correct fly wheel to hold the blades. Some torch cut home made pice of junk was on there. The correct blade holder was only $200. Seems like a good deal to me.

 

[mikester]

When I'm using the mower and run over barbed wire or baling wire and it wraps around the blades real good I go back to the garage, lift up the deck and take the blades off and then the wire just falls off.
While I have the blades off I usually sharpen them real quick with a flap disc.
Then for about 10 to 15 minutes after they are sharpened they cut amazing, then eventually I look back and there are a bunch of weeds sticking up and I have to slow back down so the dull blades can beat their way through the grass and weeds.
I can go 2x and up to 3x faster with freshly sharp blades.
I'm thinking if I hard face the blades then 10 to 15 minutes of fast cutting turns into 30 minutes to an hour. So it could really be worth it. That's probably cutting twice as much grass burning the same amount of gas and half the time that is if the blades stay sharp for 45min to an hour.
Same with the flail shreadder. The blades on it are pretty much worn out. When I get new ones I would like to hard face them too after they are broken in. The ones on there are way too far gone.
Don't worry I can ballance them. Even the individual flail shreadder blades.
If your are not familiar with hard facing rod it's far harder than any hardened, heat treated mower blade. It's so hard I had to upgrade from a 120v powered 8 inch grinder to a 9 inch 240v powered grinder just to some what effectively be able to grind it to shape when required.

The mower is a 42'' craftsman with a 17.5hp Kohler motor and the flail shreadder is on my little kubota.

Has anyone hard faced mower or brush shreadder blades?

I tried it once with nickel hard facing rods and didn't think it was worth the time, effort or money. The most bang for my buck is keeping the underside of the deck clean and avoid driving through obstacle courses - and stop to pick up hidden junk right after finding it.

I have sandy soil and the kicker part of the blades get sandblasted paper thin. I just budget for a new set of blades every spring and I put them on after the first couple of cuts.

 

[Oil pan 4]

These new ones are already starting to thin.
I get a lot of mole hills that put the blades into dirt.
I destroyed the last set of blades last fall finding junk, but it looks like I found most of it, so far everything I hit was in one corner.
Its very dry here, under the deck stays real clean.

Nickel rods are obscenely expensive and I don't recall nickel having ideal anti wear properties.
The US forge rods I used on the mower have high tungsten and chromium content.
The stoody31 rods I used on the brush shredder are like a hollow tube with chromium carbide or tungsten carbide crystals packed in them.
The US forge rods should be better impact resistant and the stoody31 rods should do better with abrasives.

 

[Oil pan 4]

The US forge high alloy homogeneous filler rod beads appear to be keeping an edge better than the unaltered blade.
But it's not a dramatic improvement, the hard faced rod tipped blade appears to only be keeping the edge maybe 20% longer. But this is still the very edge of the hard face bead where the is bead thinnest and the bead may have mixed with the base metal since it is just a single pass.

 

[Oil pan 4]

I broke the hard faced mower blade finding a chunk of concrete. It held up well considering I hard faced last years thin mower blades.
If I were going to do it again I would only hard face new 1/4 inch thick blades.

I tried high hardness carbide crystal bearing rod, the blade was cracking after 30 minutes of use.
The not as hard impact resist high alloy rod lasted 2 months.
So don't use the high hardness rods on mower blades.