Aerowave setup for 4130/DOM

[speedybob]

Greetings, my company is currently gearing up to fabricate a new product which will employ a fair amount of 4130 chromoly as well as DOM tubing & mild steel sheet metal. We have a Miller Aerowave TIG welder, which will be the primary welder for this application.

Could you possibly recommend ballpark settings for welding 4130 & 4130 to mild steel/DOM? Also, could you recommend a filler rod for these materials?

Thank you for your time & happy holidays

[Paul Seaman]

Miller sells a pocket guide that helps with the base setup. I would say cut some small pieces and practice with different settings and technique. You have good equipment for moly steel but it takes alot of practice. I have not, have not had good luck with moly steel and my tig skills, but my tig time is only a few hours and it was a rush job on a sprint chassis. No time to learn just go flow metal and make it solid, it was real ugly but it held for the time required til we got it to the builders shop for a proper jig held squared and straight and welded smoothly.

Good luck and happy welding

[bail76]

I am not sure what type of wall thickness you will be useing or the sheet metal thickness. I have ran quite a bit of .058 wall 4130 with tig and I usually run around 60 amps useing ER80S-D2 filler. This filler will work for the mild steel but if you have the option a ER70S-6 filler would probably work a little better on the mild steel. I usually always use a foot pedal to control the amperage and I will set my amperage just slightly higher than what I think I am going to need. Now if you are going to use a finger control to control the amperage running some practice beads to get the amperage dialed in will help. I prefer to use the foot pedal although their are times when it makes it difficult to move around the tubes or when you are on your back or whatever postion you might get in that is not comfortable. When picking a filler metal size for somewhat thinner material I try to get a size that is close to the thickness of the base meatl or slightly smaller. Going with too large of a diameter will take more heat to melt the filler than the base meatl usually resulting in holes or excessive burn thru or blistering of the base metal. Going with too small of a filler usually results with the filler balling back before you can get it into the puddle but most of the time this happens from too long of an arc length and or too much push travel angle. I guess if you are not framiliar with what you are going to be working make sure to get plenty of practice on mock set ups if at all possible. One other thing I almost forgot on shorter lengths of tube that will be welded solid on both ends it will help to drill a small hole in the tube to releave pressure from the welding if you don't do this I have found that many times when you are trying to tie in the last portion of the end weld the pressure will keep blowing the puddle open and it will not close off. Hope this helps a little and good luck.