welding options - stainless exhaust

[car_kent]

While it is too late to change, I looking for comments/experience on installing a stainless steel exhaust system. I'm in the middle of fitting a magnaflow 2 1/2 inch system to a 68 mustang convertible with hooker long tube headers. A local custum exhaust shop flared the collector flanges for me and said that they use regular mild steel mig to weld all exhausts including stainless. They paint the welds to avoid rust. Another local expert advised that I could use 308 stainless wire with mild steel Ar/CO2 gas. My local welding supplier said that the only correct and lasting procedure is to use stainless wire with the correct trimix gas - which is what I have done. The magnaflow system comes with clamps but you still have to weld to the collector flange, tail pipe extension and hanger bracket.

So - long story, was the expense and time of getting stainless wire and trimix gas a waste - or worth it?

Thanks,
Kent

 

[jcode68]

Sorry I don't have an answer regarding the welds, but I am about ready to pick an exhaust system for my 68 with Hooker Comp long tubes. How do you like the sound of the magnaflow? How was the fit with the Hookers? Do you have any pics of the install? Thanks.

 

[Hack]

While it is too late to change, I looking for comments/experience on installing a stainless steel exhaust system. I'm in the middle of fitting a magnaflow 2 1/2 inch system to a 68 mustang convertible with hooker long tube headers. A local custum exhaust shop flared the collector flanges for me and said that they use regular mild steel mig to weld all exhausts including stainless. They paint the welds to avoid rust. Another local expert advised that I could use 308 stainless wire with mild steel Ar/CO2 gas. My local welding supplier said that the only correct and lasting procedure is to use stainless wire with the correct trimix gas - which is what I have done. The magnaflow system comes with clamps but you still have to weld to the collector flange, tail pipe extension and hanger bracket.

So - long story, was the expense and time of getting stainless wire and trimix gas a waste - or worth it?

Thanks,
Kent

I have also been told to just switch to stainless wire to weld stainless. I use C25 gas (argon and co2 mix). I'm no expert, it's another data point for you though.

What exactly is in the trimix gas? Generally you want something that won't react even at high temperatures in a purge gas. The gas doesn't do anything other than be inert.

 

[302 coupe]

the regular steel wire is fine from a functionality standpoint, but the weld will rust, its mainly a cosmetic issue. To use stainless wire, you need to use the right gas (trimix), if you want a clean weld. The stainless weld will not rust. Whats good about the stainless weld is that you can sand it down and buff and it will perfectly blend into the pipe, and look as if its a one piece exhaust system.

 

[car_kent]

jcode 68: I don't know how it sounds yet. This is part of a complete rebuild and it will be about a week before the I test start the engine. I have the same hooker comp long tube headers. The magnaflow comes in pieces that are cut to fit. It is a tight, but good fit. I have a 351W and an AOD. The extra width of the 351 helped clear the AOD. Also, being a convertible, I had to lower the seat support connecting plate. I can post a picture soon.

Hack: Tri-mix is three gases mixed as over 90% helium, about 7% argon and just a little CO2.

Kent

 

[car_kent]

some pictures

This might help for those considering adding the magnaflow x-pipe system to a 68 conv, 351W, AOD, Hooker comp long tube headers, mustang II front end.
View attachment 44893

View attachment 44894

 

[car_kent]

more pics

View attachment 44895

View attachment 44896

 

[69 Rustang]

Is that how it looked right out of the box or did you polish the pipes and mufflers? I was looking at that kit in the Summit catalog and had filed it away for the time when my 69 is ready for it.

Could the stainless wire be used with CO2/Argon? That is what is in my tank all the time anyway. To go with Tri-mix I need to empty my tank or get another one. Buying the stainless wire isn't a huge deal if you can buy a small roll. I wouldn't want a lot of it as I don't intend to it again.

 

[NasaGT]

Could the stainless wire be used with CO2/Argon? That is what is in my tank all the time anyway. To go with Tri-mix I need to empty my tank or get another one. Buying the stainless wire isn't a huge deal if you can buy a small roll. I wouldn't want a lot of it as I don't intend to it again.

Rent a tank for a day when you're ready to do it.

 

[car_kent]

69Rustang: It shines right out of the box.

I did what NasaGT suggests. Rented a small tank (had to leave a deposit), the gas was $30.00 and I probably used 10% or less. I used a small roll of 0.030 wire, I would recommend 0.024 wire. It will weld fine with the Ar/CO2 gas, I tried it on some scrap. However, the local welding supply distributor said the the weld will be brittle and weak at the edges - so why take the chance? The tri-mix tank uses the same regulator. The amperage and wire speed is about the same as with mild steel.

Kent

 

[jcode68]

Great pics, very helpful. How do you like the way it sounds?

 

[Red5oh]

I have mine too... but I used shorty headers since the AOD. I welded with a regular mig and I love the sound. Mine is an EFI, so there is a bit of difference in sound, but the dreadded drone is NOT there. I love it.

You can check out pics on my cardomain site.

 

[thehueypilot]

It looks very nice. I would add ball flanges to the back of the mufflers so you will be able to disconnect them for easy removal for future maintenance or changes so you won't have to cut them off.

 

[car_kent]

The HueyPilot: I used the kit supplied clamps, without welding, at the muffler to tailpipe connections so the entire system can be removed with cutting. Thanks for the tip.

Kent

 

[NasaGT]

Sweet! Congrats on finishing your exhaust.

 

[jbuening]

For those with a 351w and hooker comps, do the header collectors point upwards? I had a horrible experience with my hookers and the 2.5" magnaflow exhaust. I don't have a lift so getting pics is a pain, but the collectors are aimed upwards and towards the transmission. My collector reducers are rattling against my transmission hump crossmember and all of the exhaust shops said that it is in the header and they can't do anything about it. Anyone know if hooker headers have a number stamped in them for ID purposes?