Question regarding hardfacing the edge of a tillage tool

[sixdogs]

I have a "slit seeder" for slicing grass seed into the ground with a pto powered 3 pt machine that uses a batch of rotating flat pieces of steel to "slice" the ground before the seed is dropped in. These knives, as they are called look like 1/4" thick and are maybe 2" wide and 5" long.

After use, the edges that contact the ground have worn down a bit and I figure I could use hardfacing to lengthen the knife a bit and at the same time provide a more wear resistant surface. I know nothing of hardfacing and would likely have a local Mennonite welding shop do this.

Can someone that understands hardfacing tell me if this is a good idea? Also, do you think the edge could be built up as much as 1/4"? More? Does hardfacing stay stuck or can it break off? I've got 110 of these knives. Does this welding go quick or slow? Is hardfacing available as MIG?

Any advice or comments appreciated. Thank you in advance.

 

[gwdixon]

There is MIG hardfacing wire.

Not sure if the "slicers" are made to be sharp and really slice the ground. If that is the case then hardfacing may not suit your purpose. You could have the edge built back up to OEM fairly easily with just 7018 and sharpen it from there. It would last quite a while.

Then it would just be a matter of rebuilding the slicers when they get worn down.

The "build up" should definitely be 7018 and then the hardfacing applied over that layer if you want to go ahead with the hardfacing idea.

A photo of the slicer (knife) would help.

My experience is hardfacing tiller blades, both PTO and walk-behind. Also, scarifier for box blades and a neighbors ditch digger teeth. The ditch digger teeth were quite worn so they were built up with 7018 and then hardfaced with stick. They have worn very well.

 

[sixdogs]

I'll get a picture tomorrow. They don't have to be sharp.

 

[Arc weld]

Build up rod is better than 7018 because it doesn't mushroom like 7018 will. Sounds like a good application for spray welding hardfacing. Need to see if someone local does it cause you need a special torch. Basically it heats the metal red hot and sprays the hardfacing on as a powder that melts and fuses with the red hot piece. Hardfacing will last a long time but 110 knives is fair amount of work. You want a hardfacing rod mostly for abrasion but a general purpose rod like Stoody 35 would work good if you want to do it yourself. 1/8" would work OK for 1/4" thick.

 

[Gary Fowler]

Hardfacing isn't cheap by any means. Best check the cost to do it vs new blades. Even with hardfacing it will wear out eventually. How long it takes depends on the soil as sand would wear much faster than a clay soil. If it is half the cost of new blades or maybe even = the cost of new blades it would be justified as the hard facing would likely make the blade last at least double the time even in sandy soils.

 

[yomax4]

All hardfacing material is not the same. Be sure to consider impact and or abrasion of the soil you have. Stoody has a good chart on the website to help you pick the rods or wire you need. There are some import harfacing rods from companies like weld-kote or Washington alloys that offer a general hard surface rod for $6.00# Not sure how good they are. I enjoy spray powder but you would need to bring back some of the knife with build up to save on powder. Sounds like a big job no matter which avenue you choose.

 

[CNC Dan]

There is a wide variety of welding rods available to do hardfacing. Some are for impact resistance others are for chemical resistance and some are for abrasion resistance. And various combinations of those properties. I I think you would want the most abrasion resistant. The profile should be built up if it is worn away very much before hardfacing.
I think I've heard of hard faceing rods are made to hold an edge, like on a metal shear blade.
Stoody is the biggest seller of hard facing rods and wire.

 

[sixdogs]

You guys are scaring me about the cost of hardfacing. Since I have soft clay soil, I could get by with just adding some filler metal to the end. How much would suppose I could build up with that? How about 1/4" or more? Is this filler metal available as stick only or is MIG available? If MIG, what power would I need and could I do that myself? I have a Lincoln SP 170.

I would really like to lengthen them more than 1/4" if possible.

New ones would cost $15 each so "ouch" on a whole new set of 110.

 

[whistlepig]

I did hard facing once many years ago. A welder at work hard faced my lawnmower blades with stellite rod. Bad idea. The edge so brittle that it weared much more quickly than a standard lawn mower blade.

 

[Arc weld]

Hardfacing can usually be put on 2 layers maximum but for your application, I think a layer of build up and a layer of hardfacing would be better. Hardfacing can last 4 or 5 times as long as original parts but I don't know if you could build up the outside of your discs for much less than $15. You can get small diameter(.035) MIG hardfacing but you need shielding gas as well. If would work good if you made a spinner. You should check out Stoody on line. They may have a recommendation for exactly what you want to do. They have guide books for all kinds of industries.