Need advice welding crack in tiller frame

[sixdogs]

My 6 ft tiller has a small crack in the frame that I need to fix. I don't weld many repairs like this and want to do a good job. I'm a good advanced beginner. The problem is that there is a crack through the weld in one spot and across a portion of the square stock framework. The first photo shows the frame crack at "A" and the weld crack at "B". I have a Lincoln 170 SP on 220.






The second photo at "C" below shows where the underside was never welded so I figure to clean up and weld that.





On the weld that cracked I figure to grind the weld off and re-weld. Is that the right way? On the frame part that cracked should I just clean it up and weld or should I cut a V in the frame to get better weld penetration? If so, how do I cut that groove? I have a small 3" grinding wheel, a bigger 5 1/2" grinder and I might have a grooved carbide V cutter bit for a drill. I don't weld many repairs but learned correctly at a tech school. Any advice appreciated. Thank you.

 

[hwatkins]

I'm probably an advanced beginner too on welding, but here are my thoughts.

1) The Lincoln 170 SP on 220 will be a little under powered for this job, the specs say 170 amps but it also lists 130 Amps at 20% Duty Cycle so I'm not sure you really get 170 Amp output. It looks like 1/4 inch steel, so according to the miller weld chart for Gas Mig you will need 180-190 Amps. Miller - MIG Welding Calculator

2) I would wire wheel brush the paint off and then used a sandpaper flap disk to clean the area, the pictures make it hard to tell how large the cracks are. I would grind of the weld and v out the crack. I've heard you should drill the end of the crack to relieve stress at that point also.

Good luck with the repair

 

[Cat_Driver]

I would grind back as muck of the weld as you can to square up the vertical, then weld the crack, grind the excess off the crack, then weld some 1/4" plate over the crack - sort of a band aid, to add strength to the weak cracked area. Do the same on all four sides for strength. Making sure the new plate is welded to the vertical

 

[Sodo]

Lucky these are some accessible cracks. I'd use a thin kerf angle grinder cutoff blade and open up those cracks for good penetration. And yes go past the end of the crack 1/4 to 1/2" as the metal beyond is fatigued too and has subsurface cracks, you want to grind it out and replace it with weld.

Your welder is fine, if you grind those cracks out your weld will penetrate, thats why you grind it out. Also you will know then if its 1/8 or 3/16.

Kinda looks like it cracked because they fordot a weld. Is it same on the other side? In any case due to the direction of the crack you can tell the direction of the forces and omitting the weld on the underside was not wise.

Can you post an overall pic of the structure of that tiller? I'm trying to get a picture of the forces that are fatigueing those weld joints. I agree that just welding up the cracks "just because" then add some doublers to beef it up.

 

[Shield Arc]

Who ever did the welding at the factory, should be shot!:shocked:
I'd drill a hole at the end of the crack before welding.

 

[George2615]

I know you will but just make sure to relocate that gas can in the first pic far far away before welding.

 

[sixdogs]

Here's a picture of the back of it since I just replaced the tines.



I don't recall a crack on the other side but will double check. Here's a stock photo off the website.





I cracked the implement right side which is the left side the way you are looking. It's made in Italy and gets a lot of abuse from my tilling activities of everything from hardpan clay and dirt to rocks and trash or clay tiles. Maybe I should get a heavier duty model. The damage probably occurred on a patch of really hard clay last summer where it kept bouncing on the surface. Either way, it should fix up fie with a good weld, I hope?

What diameter hole should I drill at the end of the crack?


gas can will not be near things. :laughing:

 

[Shield Arc]

What diameter hole should I drill at the end of the crack?[/QUOTE
1/4" or 3/8" at the most, something fairly easy to fill.
I've been really impressed with Lincolns L-56 Mig wire. This fillet weld break test it took 29-blows from a 4-pound hammer to break.

 

[sixdogs]

What diameter hole should I drill at the end of the crack?[/QUOTE
1/4" or 3/8" at the most, something fairly easy to fill.
I've been really impressed with Lincolns L-56 Mig wire. This fillet weld break test it took 29-blows from a 4-pound hammer to break.

Thank you.

I think that's the wire I use.

 

[sixdogs]

Oh, I have .023 Lincoln wire in now but I also have .030 if I change things over. Do I have to?