I peened them with a bolt (yes, a bolt) that had a small OD and peened the welds using my 5 pounder, hitting the bolt while they were still hot.

Time for a peening hammer!

Once a weld has cooled and has not cracked, is it good? Or do I still need to worry about thermal expansion and contraction cracking the weld under load?

Well, the problem is its a little late for that. This sucker is not coming out LOL. this filler is tough stuff! And I beaded up pretty good, its not going anywhere. I just really wanted to know what the torsional strength is on a weld like this? It will see some strain, as the torque arm coming from...

Thanks man. Im really embarassed to say I did that, but Im learning and I worked for HOURS to achieve that, seriously. Luckily that mount doesnt get that hot, so I should be in good shape

I believe I had success. I welded the area again with the 308L that I had, and the results arent pretty, but I beat the area repeatedly with a 5lb sledge and no cracks whatsoever. Dont laugh, but heres the weld (after I ground it down) Look at the fusion between the housing and the square bracket. H...

If you look theres a mild steel "box" that you weld together, then weld it to the housing. Its for the torque arm that attaches to it from the transmission, and butts up to the housing (in most areas) It sees flex forsure, but Im not sure how much It is also reinfornced by steel thats actu...

So should I cut it out and try ni55 again? Its very strong but I will cut it out if necessary. Theres two sides, and I believe I was welding at a better angle on the side that held. Should I order some 309L to be on the safe side? Already ordered some 1/8" ni55, I believe that the gap is a tad ...

Welding a cast iron differential housing from a car, and I had to make a special steel mount for it. The mount has to be welded onto it, and no matter what I tried the Ni55 rod would break under stress (I would pound the mount with a 5lb sledge and the weld would break clean in half) I had some 308L...

Thanks for the reply It has already been confirmed it is a gray cast iron, Luckily multiple sources have confirmed The only thing I need to figure out now is - AC OR DC Stick welder with nickel rod? It looks like DC will work and is the cheapest, but some people report the best luck with nickel rod ...

Looks like stainless rod wont be strong enough. This bracket bolts the torque arm to the differential of the car, alot of torque involved. Looks like I can buy an inexpensive stick welder off Amazon (200amp DC). Use some nickel rod. Will be less expensive than nickel wire for a MIG. What do you thin...

It will see tremendous amounts of torque. It is a bracket that holds an arm to the rear differential of the car for traction (torque arm) It looks like I can just buy a stick welder off of Amazon and buy some nickel rods. I will try to get some pictures later, but here is what I will be doing. What ...

Thanks for the reply.

Looks like I can make it happen with some 308 stainless wire. Anybody have experience with this?

New guy here, thanks for the add guys! Purchased a LOTOS 175A 220V Mig machine, looking to weld On a cast iron differential from a car. Essentially I will be welding what seems to be 1/4" thick steel onto the housing itself. What I did not realize was the price of Nickel wire. Its expensive! Sh...

Hey guys! New here. Just bought a LOTOS 175A rig. Made a mistake, I need to weld steel plates onto a rear car differential (cast iron) It seems people have had success using a MIG, but most stick it or tig it. I need help locating the proper wire and gas mixture for the job. It looks like a nickel 5...