Welding Tips and Tricks

I have a job on Monday 6/08/2015 involving welding stainless steel bolts that will protrude outside of R-panel to hold tankless water heaters. The heads of these bolts (hex 1/4 20) will be against steel purling. A 1/4" hole will be drilled through the purling, and the head will rest on the inside. I will weld them when the heaters are attached. Thickness of purling is < 1/8". These bolts are not very structural at all. Four of them will hold the heater weighing about 50 pounds. I just don't want them to fall inside of the wall they will be concealed in if any of the heaters have to be removed for service. I think that 309 stainless rods might be the right choice? Welder: Miller Bobcat 225NT. Planning on using about 75 amps DCEP. Does this sound close to right? I will make a trial run in my shop over the weekend. Thank you for any help!..Robert

Can't help you with the amps but 309 is definitely the rod to use

weldin mike 27 wrote:Can't help you with the amps but 309 is definitely the rod to use

Thank you! I was mainly wanting to make sure my rod choice was right.

3/32" 309 should work great. 75 amps would be a good starting point.

1/4" bolts seem kinda small to be holding 50 lbs, but that's just my seriously unqualified opinion.

The point of these welds is to secure the heads against turning. You add NO structure by welding them all the way out as the purlin is the weak link. Tiny stiches on three faces of the bolt head should be sufficient.

Steve S