Welding Stainless Steel - shielding gas question

[kamaroman68]

Matt nice to see you back here!!!! Tried sending to your personal e-mail but it got kicked back saying unfound email address or something like that. Chris

[Matt@RFR]

Hey Chris, hit it again. I fixed 'er. I need to have Larry change my username too. One of these days.

[cm-67]

Matt, I disagree. There are gasses that will produce better results than others. I say A-1025 because it gives me the cleanest, best looking weld of all the gasses I have tried. Sure you can use other types but results will be different. When I use A-1025, it produces a flat (minimal buildup) weld with virtually no splatter. Whereas with other gasses the weld will not penetrate into the base metal as well and may splatter badly regardless of the settings.

A-1025 contains 90% helium, 7.5% argon and 2.5% co2

I can tell you that I have used it on 304, 310, 316, and also 321 stainless steels all producing the same results

As far as using it on other metals, I do not. I know that 75/25 is going to give me the best results with mild steel. At my shop we have a pulse mig that we use if we have to mig weld aluminum.

When I am tig welding I always use straight argon for ss, cs, and aluminum.

I always prefer to tig stainless and aluminum. Tig welding produces a much cleaner weld with more control, better penetration into the base metal and less cleanup. Mild steel I could go either way.

Chris

[Matt@RFR]

There are gasses that will produce better results than others.

I always prefer to tig stainless and aluminum.

My opinion is that you speak way too generally. For example, you always prefer TIG on stainless? Always?? A few years ago I helped make 140 parts to make up San Francisco's new waist water purification plant. Those parts were big, all 316, took us atleast 4 months with 8 guys working on them and we went through about three pallets of 316L hard wire...much of the time laying on our backs on the floor welding the base frames and such. Would you have opted to TIG weld those?? Oh, and guess what gas we used. That's right, regular old tri-mix. We tried others, but the added cost of buying blends that are not as widely used was not worth any minute benifits they gave us.

Typical tri-mix is 90% helium, 8% argon, and 2% CO2.

A-1025 contains 90% helium, 7.5% argon and 2.5% co2

Yeah, I'm not buying what you're selling Chris. 1/2 a percent will not make a big enough difference for me to give two ****s about. Not when gun angle, weld prep, pre heat, individual operator settings, wire alloy and quality, base metal quality, gas flow, stickout, etc, etc will probably all have greater effects than a 1/2 percent difference in your gas blend. Either one of you has their numbers wrong, or we might also be seeing a locality effect. Just like buying 3003 H-14 aluminum sheet is as simple as asking for it at your local metal shop on the east coast, whereas on the west coast, you have to order it, and most shops have never even heard of it.

We'll just have to agree to disagree Chris. And in reality, when a guy comes to an automotive message board to ask what gas to use on stainless, my bet is he won't get any benifit for his task with an in depth discussion of gas blends and such. However, that takes an assumption that he's not welding anything important, so shame on all of you for not asking what "Asia" is going to be making. If he's making a stainless dash for his car, either tell him that 75/25 will work just fine if he's going to grind the welds, or simply tell him to tell his welding supplier that he needs to MIG weld stainless and to set him up with gas (as long as it's not pure argon! who the hell told you that?). BUT, if he's welding a tank for a local farmer which will hold some kind of acidic liquid, the situation changes drastically.

Talk amongst yourselves, I'll be back in a few months.

[cm-67]

Matt,
Either you misread my post or you have a very narrow knowledge of welding.
You acuse me of being too general, when in fact tri-mix is about a general a term as it gets.

#1 A-1025
#2 Stargon : argon, co2, oxygen
or argon, co2,, nitrogen
#3 Helistar : argon, co2, helium
#4 Robostar : argon, helium, and oxygen

All of these gasses are a tri-mix in that they have three gasses. However the blends and percentages are different and each will produce a different result.

You use the wrong shielding gas and you will be rewarded with a weld that is full of porosity, lacks penetration, and will be covered in spatter.I do agree that all of the other things you mention are important as well.

Chris