what welding wire to use on rake

[taem]

My son is repairing an older Kvernland rotary rake we have. The arms are breaking off just beyond the hubs they are mounted on. Oddly there are two kinds of arms, those with one bolt hole which are breaking due to more slop, and those with two which seem pretty good. the hubs all have two bolt holes. His proposed solution is to find some slightly larger tubing, weld a sleeve over the end of the arm from the hub closest to the spinner to beyond the stress point and drill two holes to mount the arm. So far so good,but the question is what type of Mig wire should we use? We will probably have to use low carbon tube for the splints as that is what is available locally, but the arms are obviously some sort of alloy since they are much springier than mild steel. Our usual wire is ER 70S-6 which is for mild steel. What wire should we be looking for? Do we need something specialized? And where would we be able to find the kind of steel the rake arms are made of to make the splints, since that obviously would be the best to use if we could find it. Thanks

 

[Janicholson]

From the site- GoWelding: For medium carbon steel electrode and gas selection is pretty easy. In most cases the filler wire will be ER70s-6. The gas choices are either straight Co2 or a C25 Gas that consists of 25% Carbon Dioxide and 75% Argon. The C25 mixture does produce better weld quality but also cost a bit more.
Jim

 

[Little Ed]

I'd try the ER70S6 and pre-heat it hot enough to not be able to keep your hand on it, make the weld and then bury it in floor-dri, or dry sand, so it will cool slowly.

 

[JimKS]

Do not weld it to hot. being in the repair business for 50 plus years I have repaired more welds that were done to hot than to cold.
Jim

 

[rlp in Co.]

I have doubts that it will work. I tried welding car springs one time. It didn't work. Can't you buy the spring teeth?

 

[taem]

Not the teeth, the rotor arm closest to the center cam has cracked and some have broken. the pipe itself has cracked. Actually we finessed the problem by reaming some thick wall tubing to the OD of the arm and then pressing it over, drilling and clamping the splint. never did have to weld the tubing which is mild steel to the alloy tube below.

 

[BarnyardEngineering]

My Dad would have welded it up with 6011 and called it a day. Probably would have held up fine.

In other words, I don't think it's as critical as you are making it out to be. Try with what you have. I bet it will work just fine.