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