Stainless exhaust b-pipe

[Wrenchtamer]

It looks like that flux works really well. I am gonna have to pick some up to try out for my next stainless projects. Anyone compare the flux to back purging? Is it cheaper to use one verse the other?

I just did a ton of stainless exhaust tubing for a set of custom headers. The fit up was pretty poor and there was a ton, I mean a TON of welding to be done on them. they were constructed from an assortment of mandrel bent pieces by the fab guy at our shop. Basically he just cut a bunch of pie slices out of the various pieces of tubing to get the general shapes down and brought it to me for welding. With the long pieces I was back purging with pure argon but that is much harder to do with a two or three inch piece because of the heat generated. I went and bought some solar flux and let me tell you that stuff is awesome. It burns black when you weld over but seems to sand out ok.. It is cheaper and easier welding than back purging, but if you are filling big gaps like I was and the flux gets to the topside of the weld it makes it a little difficult to tell where the flux is and where the base metal is. the flux will melt and puddle and accept filler just like the base metal so you have to really make sure to get the heat in there. But IMO overall the flux is better and less problematic than back gassing. I also had to weld the inside of some of the joints which isnt possible when purging. I got a one pound can at local LWS for about 40$. It was totally worth it if you dont already have a spare bottle and regulator or a dual regulator.