irk miller said:Hurco550 is an excellent welding instructor and a great resource. I'm surprised that dude hasn't jumped in yet.
You must have heard that from my publicist, I guess he earns his wages lol you know what they say, those who can't "do" teach
Maritime said:I think people pre-heat the head stock but I am not sure, I am not a welder. But I have watched some of our fabricators at previous job weld very thick alloy to very thin and they pre-heated the thicker metal right before welding.
teazer said:Correct. the larger/thicker part has to be heated first so that both parts are brought up to the same temperature at the weld point. Where the torch is pointed makes a huge difference as you weld. bias it towards the thicker part and watch what is going on with both parts as well as the weld.
Don't know how I missed this thread so far, but really neat project coming along here!xb33bsa said:all the above =preheat i would go 400 then weld then post heat wave a torch at it so the weld zone continues to spread some heat then cool slow by backing off the torch slowly or better yet wrap it in some insulation
I'd jump in on some weld advice, but it has all been well covered here. And yes, er70s filler (both mig and tig) aka standard mild steel filler is the go to for chromoly. Not just chromoly to "regular steel" but also for chromoly to chromoly.
I built some roll cages for pulling tractors as well as one for a Baja 500 truck, all using er70s-6 for filler. Baja truck rolled in the first 50 miles, and the cage held up.
Basically, as with brazing, the use of a less hard more ductile filler aids in the avoidance of cracks. If you used a filler with matching tensile strength as the base metal in a focused stress location (I.e. Most weld joints), you will almost un doubtably have cracking. Still though, in er70s wire, the 70 means 70,000 p.s.i minimum tensile strength in a PROPERLY DEPOSITED WELD. That last part is important ha
Cheers with the build my friend, excited to see it come together