Welded cast parts on sickle with a MIG!

Sodo · May 17, 2015

I bought an old Massey Ferguson MF-31 Sickle mower for $150 (?). It was a challenge to get it going, the main wobble box shaft was broken and I welded it with my MIG. (Story Here)

I've been using it and decided that I like a sickle mower! Time to replace some wear parts though ("past" time!). I located the replacement guards and sickle knife sections at Webbs Sickle service and they were very helpful, but unable to provide the sickle-bar hold-down clips. So I bought the parts that they had, and resolved to keep looking for hold-down clips.

Well now the grass is growing, and I have not found any hold down clips, so decided to repair them. I know a bit more about welding cast iron now, but still wondered, if i'm just adding a wear-surface, why not see what happens just welding it with the MIG?

Welding cast steel with a MIG may be illegal in seventeen states but I did it anyway, and it's FINE !

Installed the new guards. Paint is worn off because this pic was after I used it.

Heres a pic of the worn-out clips. You can see that the sickle bar is almost touching the bolts.

Ground off the rust and opened it up a little.

Welded a 1/4" rod into the worn out section of the clip. Also added some steel to the 'finger' on the hold-down clip.

Ground it flat again.

Here's what it looks like installed. I am on the lookout for replacement clips. But it's not all that urgent as the mower is working great.

Baby Grand · May 17, 2015

Impressive repair, Sodo & looks like it should work fine.
Using the 1/4" round stock was very smart - you wind up with a nice edge without any machining.

Gary Fowler · May 17, 2015

I have welded a lot of cast steel using 7018 rods and they hold as good as new. On my Yanmar tractor, the bolts that hold the lift arm bracket to the rear axle continuously worked loose and I finally lost the bolts so I just welded it solid on to the bottom of the tractor axle. No more lost bolts, and it held together till this day and I pulled an 8 foot 1500+ pound disc with it many times. My brother in law still uses it with the Howse bush hog that I sold him.

Gary Fowler · May 17, 2015

I forgot to mention that the last time the bolts came out it buggered up the threads which is why I just welded it rather than try to chase the threads and get new metric bolts and I got tired of buying $$ each bolts.

rswyan · May 17, 2015

Sodo said:
... I know a bit more about welding cast iron now, but still wondered, if i'm just adding a wear-surface, why not see what happens just welding it with the MIG?

Welding cast steel with a MIG may be illegal in seventeen states but I did it anyway, and it's FINE !

Cast iron and cast steel aren't the same thing ...

Gary Fowler · May 17, 2015

rswyan said:
Cast iron and cast steel aren't the same thing ...

That is true. To me cast steel welds no different than low carbon steel. It isn't as brittle as cast iron and much stronger.

I have also welded some cast iron with 7018 with good results. In some instances there is no need for the high nickel content rods for welding cast iron. Mostly it depends on how the material is shaped. An intricate design is hard to weld together due to the expansion and contraction ratios of the parts. A solid thick piece welds pretty easily and wont crack out like smaller pieces even with 7018 electrodes. Proper pre-heat and post weld cool down is critical.

Sodo · May 17, 2015

I suspect this is working out because the parts are small. I would have preheated but my torch was out of sorts, and,,,, the parts are small, seemed like it would work out.

I "fixed" all 9 clips, the one pictured is the worst one. I know you guys like carnage.

So it must be cast steel - if it welded OK? Also it doesn't seem like original part would be strong enough if it was cast iron. I need to find some cast irin then and try a bead on it. Like a spark test, i suppose you could use a welder to identify cast iron .vs. steel.

On the hold down finger, you can see the puddle oxidized a little, its really thin there, puddle was really HOT. On some of them it almost fell thru.

View attachment 425199

The weld behaved better when I could dwell a little longer on the steel rod & drop off onto the cast then get back on the steel rod.

4570Man · May 17, 2015

A tried welding some cast iron with a stick and a mig. It welded nice but wouldn't hold.

Sodo · May 17, 2015

4570Man said:
A tried welding some cast iron with a stick and a mig. It welded nice but wouldn't hold.

How big was this chunk of cast? How thick was it in comparison the the bead size?

rankrank1 · May 17, 2015

Nice work on repairing those cast hold downs but is there a reason the common run of the mill universal stamped steel sickle hold dowms from TSC, Rural King, Webbs would not work?

Anywhere from $4 to $5 a piece at TSC (and likely even cheaper everywhere else).

copy and paste links here:

Low Arch Hold Down Clip, Pack of 2 - Tractor Supply Co.

or

Hold Down Clip, 2 lb. - Tractor Supply Co.

Course now that you repaired those others, I would wait for them to be worn out again before replacing....or at least worn some. Typically as these hold downs wear you can hit em with a hammer to tighten the the hold down again some. Your welded ones may have lost some of their mallable properties to be bent down again without cracking but will still last quite a while as repaired.

PS: I have welded unobatainable caste iron parts with flux core E71T-11 wire feeder on my old hay rake and they have worked fine for years now. One of my hay rakes is a 1938 the other is a 1948. Migging with gas I am quite sure would have done it even better than flux core. Part of my success was the high quality of the vintage john deere cast from the 1940's which supposedly already had a lot of nickel in it or so I have heard. If it had not of worked it was off to the junkyard or fencerows in search of used parts so I really had absolutely zero to lose other than my time. I even used a 115 volt wire feeder to do it too (although a top quality 115 volt unit - no junk).

Sodo · May 17, 2015

Looks like those stamped ones would work but I think they'd need a "thrust spacer" (?) too, (under them) for the back of the knives to rub on. TSC search function is not very good, cant find the related mower items.

I like the idea of the clips pressing the knives down nearer to the serrations, most are 1/8" up even 3/16,,,,, but I sure wouldn't hit mine with a hammer! I mow a small field about 3x per year, it may be awhile.

It squeaks sometimes then I cut thru some gopher mounds and it quiets down.

4570Man · May 17, 2015

Sodo said:
How big was this chunk of cast? How thick was it in comparison the the bead size?

I was welding a piece of 1/4 plate steel to the bottom of some rail road track. The bead was probably 3/8 wide.

Sodo · May 17, 2015

Ok so most of each item remained cold? Or did you preheat?

4570Man · May 17, 2015

The joint remained mostly cold, but when it broke it pulled a crater out of the cast iron along the bead.

4570Man · May 18, 2015

This is the crater. It is about 1/4 deep.

MHarryE · May 18, 2015

Rankrank1 beat me too it - sickle sections, guards, wear plates and hold down clips are rather generic. There are 2 standard hole spacings. Guards have different profiles but are made by many after-market suppliers because when sickles were in their prime all these wear components were a cash cow. However there is not one universal design. We all had our own tweaks trying to keep replacement parts as an in house profit base for our dealers. But that is the quick and easy solution. Your building up the original forged hold downs (are you sure yours are cast iron because older ones we had were forged steel) makes a better part. We changed to stamped steel parts for reduced cost, not improved durability. Working in a forge shop has to be one of the worst jobs ever created. Changing to steel stamping in a progressive die resulted in one completed part every press stroke or about one per second at our plant. Then on to heat treat, coating, and to the line for installation. Yes, the replacements you find will generally look quite different but do the same job.

Sodo · May 18, 2015

4570Man said:
View attachment 425442 This is the crater. It is about 1/4 deep.

So the weld just cracked away from the cast and the whole weld came off with the 1/4 plate? I guess thats what I would expect, and less likely with preheating the cast to dull red.

These clips were so far gone I was suprised they didnt fall apart before, during and after the weld. Because of that I looked for the forging flash ground off or other clues, they're not forged. These clips look like they were cast. One of them was bent, I suppose by trying to cut steel (fencepost?). I would not expect it to bend but rankrank says they do.

4570Man · May 19, 2015

That is exactly what happened.

Sodo · Sep 17, 2015

This hook broke off. I welded cast again with the MIG. Wondering if it's gonna hold. This is the mechanism to raise the mower, and provide the ride height above the ground, the hook is essential.