View Full Version : Exhaust Welding Question
03-22-2009, 05:03 AM
I have purchased an aftermarket Stainless Steel exhaust system for my truck. I need to weld several SS round bar hangers to the 4”, 14 gauge, 409 stainless steel tubing. Can I mig weld these together with ER70S-6? If ER70S-6 is not correct, is there a different mig wire to use?
03-22-2009, 05:25 AM
You need 409 or 430 filler rod. Cant use steel. That would contaminate the stainless in that area. Unless you want to spend the money for a stainless gas mix and a spool of wire look to clamping the hangers on.
03-22-2009, 08:35 AM
Got to agree, unless you are going to be welding enough stainless to justify the investment in new wire and gas that could turn into some expensive welding. If there is not much load on the weld and you are not concerned with appearance however the ER70S-6, while certainly not the correct wire, will weld fairly well to the stainless. BE WARNED however this is not the right way to do it and the weld will not only be somewhat weaker (but not as bad as some might think) it will rust in the area around the weld. Now before the welders here get out the tar and feathers and come after me I too argued this was a bad idea but as was pointed out to me, right or wrong, some muffler shops do it all the time.
03-22-2009, 09:42 AM
Thank you radkins and macona for your responses.
Although I do have a nice tig machine, I don't know how to use it yet. I'm also not sure if I have 409 or 430 rod. Another main problem is I really need to get the truck on the road again. Question: If I was able to get some mild steel in 14 gauge (same gauge as SS exhaust pipe), and some mild steel rod in the same diameter as the SS hanger rods (mild steel being less expensive), and then practiced tig welding these together. Then, if I switched to weld the exhaust with the proper SS rod, would my settings on the tig machine be close enough for it to weld properly? If not, what settings would I need to change, and which way and approximately how much of a change? By the way I have a Miller Syncrowave 250DX, if that helps. I apologize if I'm asking too much or too specific of questions, I really don't know much about tig welding other than reading. I found a teacher who is willing to come to my shop to teach me tig welding later this spring, but until then... I really appreciate all the information you guys are providing me. I love these forums, I've learned so much from so many people.
Thank you again,
03-22-2009, 10:04 AM
Question: If I was able to get some mild steel in 14 gauge (same gauge as SS exhaust pipe), and some mild steel rod in the same diameter as the SS hanger rods (mild steel being less expensive), and then practiced tig welding these together. Then, if I switched to weld the exhaust with the proper SS rod, would my settings on the tig machine be close enough for it to weld properly?
The scenario you describe would get you in the ballpark.
Download the Miller TIG manual for more in-depth info.
03-22-2009, 10:05 AM
My mig was welding just great with stainless wire and argon. Tri-mix. With oxygen to heat up the weld is the normal to use with a household mig.
That over the axle bend? If you can index it on the car, then remove it.. ohh so much easier.
Can you braze? if so, you can tig weld in a few hours to a point of hooking things together. Once you learn puddle forming with a torch. THE upside down tig welding still gives me fits. It droops like well grandpa's saggy overalls..
I was amazed to see how easy it was welding with a henrob acteylene - ox welder. Just building puddles like brazing.. then I got the tig machine going. Mine is a 200 Miller.
03-22-2009, 11:23 AM
Thank you radkins and macona for your responses.
Although I do have a nice tig machine, I don't know how to use it yet. I'm also not sure if I have 409 or 430 rod.
Thank you again,
Whoa!! I didn't realize you had that kind of equipment available and with just a bit of practice you should be right in the driver's seat. :) That's what I would recommend since you have the equipment but the MIG with carbon steel wire would work in a pinch.
03-23-2009, 02:03 PM
Just because you have the tig machine and the right filler still won't make a really good weld without back purging the system in the vicinity of the weld zone.
You're weld would be sugary and just a little stronger that if you welded it with Mig/S-70
I welded my whole SS exhaust system together with the same. It's two years old now and no problems.
Why did I do that?
I asked the muffler shops who install these all the time...all they ever use is mig/S-70
03-24-2009, 09:02 AM
FOR the less "welding educated people" S70 mig wire is a high tensile strength wire (70,000lbs??) as opposed to the "easy grind" wire they throw onto the counter at the welding shop for a newbie.
Easy grind is just that. for body panels where you want to add metal and grind it smooth for bodywork. Structural integrity does not matter. Welding important things of things that might crack and fall off are not a option with it.
I have a alloy stainless wire, two spools, one 340, one 430? I use on stainless. I swapped my tri-mix gas for two tanks of Argon. One is always on the miller 200 tig rig, other floats about on the mig. I keep dropping the bottle. I've bought two regulators now.
IS this a polished streetrod system? if so.. WHOOAAA... put the right metal into the seams. I got a polished set of stainless headers on the wall I did some stick welding next to.. I foresee hours of cleanup. TIG is MILES easier to clean up and polish than MIG, there will be so much splatter beads on everything you will curse everyone on the forum.
JUST DO IT, get that tig out, read the basic instructions and start melting metal together.. Covell has some excellent videos on youtube.. Making a bench weld of a traveling bead on flatstock. Practice your catipillar back, puddles... put a piece of copper down or like when I started the part will be welded to the table real well..
If you are like me, you need to do the best you can, cause you can not depend on anyone else to come over at the right time.
03-24-2009, 02:34 PM
I keep dropping the bottle. I've bought two regulators now.
:eek: :eek: :eek:
Torpedoed one yet?? Umm I hate to be a nit picker, but seriously, consider a cart to tie the cylinder to before you do torpedo a bottle by knocking off the main valve. I enjoy your posts too much not to say something!;)