Welding high(er) carbon steel

I have a garden tiller (that I got at the dump). In use it leaves about a 6" wide untilled strip in the middle. I want to reduce this by extending the middle blades/tines. The easiest, fastest way is to weld pieces on. But the tines are pretty hard, to resist being worn down, and I feel that just welding on them will leave a brittle HAZ.

Will this work: anneal them, weld on the extensions, re-harden, and temper? I hope so, 'cause the alternative is drilling & bolting and I find that very unappealing. And sure to work loose.

Thanks, Bob

Reply to
Bob Engelhardt
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Rivets?

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Magic Sickle Hardware?

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--Winston

Reply to
Winston

Or, can I just weld without annealing, then temper to relieve the HAZ?

Bob

Reply to
Bob Engelhardt

The steel is likely some .7% to .9% carbon steel. That is going to be high enough to give you nasty weld issues. But it also begs the question of what stock are you planning on welding on? Some plain hot rolled bar stock is not going to cut it.

Reply to
RoyJ

I was to use some OCS (Old Chevy Spring). In fact, the original plan was to use the OCS to make whole new tines, but there were complications.

Thanks. Not what I *wanted* to hear, but what I needed to hear. The bottom line seems to be that no matter how I do it, it's likely to be soft somewhere. Then I'd be stuck & worse off.

Maybe drilling & bolting isn't that bad of an idea. Maybe pinning & bolting.

Oh, wait - here's an idea: if I do the welding along the edges of the tines & not across them, then with option 1 or 3 (softness in the HAZ only) I wouldn't get bending. The leading edge would wear faster, but I can handle that. Or use plug welds & avoid the soft edges too.

Thanks again, Bob

Reply to
Bob Engelhardt

Bob Engelhardt wrote in news: snipped-for-privacy@news6.newsguy.com:

Just a stupid question here, Bob, but did the tiller come with its drag stake?

This is a metal bar that is fitted between the sets of rotating tines to both reduce the pullback force and to act as a "middlebuster" as it is pulled through that untilled strip in the middle.

If it didn't have one, it *should* still have the bracket to which it would be attached.

A suitable piece of bar stock (.250/.375 x 1.0) can be easily drilled to make a replacement stake.

Reply to
RAM³

I think we have a winner! You're right - there is a "leg" in the=20 middle, with drilled holes, but something is missing. I didn't really=20 accept that the tiller was supposed to leave such a wide strip ... but=20 there it was.

Now, this "drag stake": would is it supposed to look like, geometry wise?=

Thanks! Bob

Reply to
Bob Engelhardt

I've seen them made similar to a miniature plow head (like a horizontal arrowhead with a vertical bar attached at the midline) or built like a simple "T" shape, with the flanges going to the sides, not front to back.

It provides a certain amount of drag as it cuts dirt to compensate for the speed of the tines, otherwise the machine would run away from you, or on a tractor, it would be pushing you.

Some are adjustable (picture an adjustible hitch setup, where you pull the pin to slide the bar up/down to set depth), some are fixed.

Geometry is usually designed to either simply provide a leg for the machine to stand on- avoiding damage to the tines. Or it is designed to actually dig in (arrowhead shape) and can be adusted for depth control. Either design should slow down forward velocity and encourage digging by the tines. Just don't angle the arrowhead too steep-- I would recommend keeping it within 5 degrees of flat.

Good Luck!

Reply to
TinLizziedl

On mine the drag bar is angled at about 15 degrees off vertical, facing forward. It is completely free to pivot forward, locked so it cannot go past the operating position. In use you jam it into the ground to counteract the tines, lift up slightly on the handlebars to let it claw forward, then push down on the handlebars. When you come to the end of a row you shut off the tines, pull back, the drag bar pivots out of the way. For transport, the drag bar has an extra hole that lets you position it out of the way, just drive it on the tongs.

My unit is buried (deeply ) in the shed, IIRC it is 3/8" x 2" plain bar stock (not hardened) with a 45 degree cut on the business end, holes abut every 2" for depth adjustment,and the aforementioned transport hole.

Bob Engelhardt wrote:

Reply to
RoyJ

I just took another look at my bar. It is L-shaped with the long vertical leg drilled every inch or so for height adjustment (held by a pin). The short horizontal leg has 2 holes that must have held the breaker bar. E.g., a plow or arrow.

I had assumed that this was just a leg to keep the tines at a certain depth. Although it didn't work real well for that.

Something I didn't mention is that the tiller is rear tined & self propelled (driven wheels). So that it doesn't need to be held back - it goes at the wheel speed.

Thanks, Bob

Reply to
Bob Engelhardt

Thanks, I think that I have the picture now. Mine isn't angled (much, at any rate) & doesn't pivot, for sure. And has a trailing leg that held some kind of cutter, I think.

I'm going to make up a cutter to bolt on & try it. WAY easier than the tine extensions that I was planning!!

Bob

Reply to
Bob Engelhardt

What's that Lassie? You say that Bob Engelhardt fell down the old sci.engr.joining.welding mine and will die if we don't mount a rescue by Fri, 30 Oct 2009 20:16:50 -0400:

If you ever do need to weld someth Pre-heat to 700-900 F., use a nickel rod for ductility, cool slow.

Reply to
dan

replying to Bob Engelhardt, mariaarcia wrote: The unfinished surface of high carbon steels is dark gray and similar to other steels.

Reply to
mariaarcia

replying to Bob Engelhardt, mariaarcia wrote: The unfinished surface of high carbon steels is dark gray and similar to other steels.

Reply to
mariaarcia

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