First off, I'm planning on using the stainless MIG mainly for tack welding in order to TIG it later. Using a TIG to tack together after mock-up is a pain.

1) What wire alloy should I get, like 316, 308, etc?

2) What wire size? I have tips for .035" and .025", it its a 120v Lincoln thats not doing much any more.

3) Will straight Argon be okay for welding? At the most it will be a 1/2" long bead I have to do, and I do have a 20cf bottle doing nothing...but atm I have no $$$ to get tri-mix, while I do have a 120cf bottle with 100% argon. They generally aren't strucural welds, mostly have to be vibration-resistant.


The info I've found is mostly for TIG, and always for continuous welds, so I'm looking to you guys for help.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">First off, I'm planning on using the stainless MIG mainly for tack welding in order to TIG it later. Using a TIG to tack together after mock-up is a pain.

1) What wire alloy should I get, like 316, 308, etc?

2) What wire size? I have tips for .035" and .025", it its a 120v Lincoln thats not doing much any more.

3) Will straight Argon be okay for welding? At the most it will be a 1/2" long bead I have to do, and I do have a 20cf bottle doing nothing...but atm I have no $$$ to get tri-mix, while I do have a 120cf bottle with 100% argon. They generally aren't strucural welds, mostly have to be vibration-resistant.


The info I've found is mostly for TIG, and always for continuous welds, so I'm looking to you guys for help. </TD></TR></TABLE>

1 - one step up in alloy for the wire type. so if your welding 304, use 308 wire. you can tack with this to mild, but use a 309 rod for the finish weld.

2- the thinner the wire, the less amperage you have to use. since your tacking, your not going to need to penitrate fully. this will keep down on the size of the tack.

3 - you can use regular, tri mix or argon. tri mix isn't worth the extra cash.

if you can use a tig to tack, thats best.


Modified by manifoldmiketyson at 1:14 AM 11/28/2007

 

Thanks for the help, but I can't use a TIG to tack, mine isn't a baller HF-start

I was reading on this site I found that I'm probably going to be sorry regardless, and raises another question. I'm finding mainly 400-series tubing for exhaust, and it has the two downsides of becoming brittle from the rapid cooling, and from 'requiring' 309 filler. I'm hoping to find a good general-purpose wire that works mainly on 409 I guess, with just tacking 316 on occation.

Also for the gas, are you suggesting normal C25? I have an 80cf tank on my MIG, so that would work great.

What I find strange is that the company I find good prices on stainless 3" bends and piping uses 409 for the pipe, but 304 for the bends.


btw this site is pretty helpful:

http://www.esabna.com/EUWeb/AWTC/Lesson1_1.htm

 

409 is sort of a mix between mild and stainless. its a little more brittle and it will surface rust. reason your finding it so cheap is because its used in oem exhaust.

lasts much longer then mild and cheaper then regular stainless.

if your going to coat it, i would use the 409, if not, stick with 304, 316 or 321.

 

you need something with helium in it...normally like 90 he 7.5 ar and 2.5 co2, if you use the C25 it will work, but it will rust

 

You want Tri-Mix gas or 98/2 Argon/Oxygen or 100% Argon. Tri-Mix gives the best results.

 

For tack welding I use the same tank of Argon that I use for TIG. It leaves a high crown on a bead weld, but I only use it for tacking so that's not a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">you need something with helium in it...normally like 90 he 7.5 ar and 2.5 co2, if you use the C25 it will work, but it will rust</TD></TR></TABLE>

 

argon works. i was thinking the other way around. i tried using a regular mig mix for tig once and that didn't work at all.