TIG WELDING 304 STAINLESS

By Lawrence (*****)

Date 09-20-2005 16:07

Your 16 Ga. should require about 70 amps max.
Stickout limited to the dia. of your cup.
No noticible drafts in the work area.

On a piece of scrap:
Try running your Argon at about 20 CFH and striking an arc with your torch perfectly at 90 degrees. Depress the foot pedal until you have a puddle about the diameter of your electrode and then taper off slowly until the puddle freezes. Don't add wire, Don't move the torch for 10 seconds to allow some post flow to cover your metal while it cools.

If you find:
A silver, gold or light blue, your in good shape. And your problem was probably torch angle.

Grey crusty surface you still have a coverage problem.
Check fittings to see that your not sucking O2
Still bad? Now you can suspect contaminated argon.

By MDG Custom Weld (***)

Date 09-20-2005 16:34

304 and 316 tig weld almost the same. I think that your gas flow might be too low. As stated above, try some samples with your Ar at 20cfh. Make sure your filler is not dirty or oily. Using 316 for filler is really not the best choice for 304, but it will work depending on the service application of the brackets you are making.

By COMBAT Date 09-21-2005 01:09

THANKS FOR THE INFO. I TRIED THAT BUT THAT DID NOT SEEM TO FIX THE PROBLEM.

By Jim Hughes (***)

Date 09-21-2005 19:00

COMBAT,

can you tell us if it's L-grade 304 material? If it's non L-grade then it's going to run different. If it is L-grade it will say 304L. If it is L-grade then try lower amperage. 14 gage is about 1/16" thick. Also use a gas lens. A gas lens is great for better coverage but also as a cooling agent.
Jim

By Lawrence (*****)

Date 09-21-2005 19:05

Jim

You got me........ What exactly does a gas lens cool???

By Carmen Electrod Date 09-23-2005 16:09

A gas lens collet body provides a number of benefits for all but the most basic of applications. The primary benefit is improved shield gas coverage. This is achieved by flowing the shield gas past a series of concentric, layered screens of varying mesh. These screens generate a laminar gas flow which optimizes the weld zone coverage and eliminates the turbulence created by a standard collet body which can draw in contaminants from the surrounding air. A gas lens collet body is almost mandatory for TIG welding oxidizing materials such as aluminum.

A secondary benefit of this improved shield gas coverage is that the tungsten electrode can be extended beyond the end of the gas cup by as much as 1 inch (2.54 cm). This electrode extension greatly improves welder visibility and can reduce tungsten inclusions and weld defects.

By Lawrence (*****)

Date 09-23-2005 18:35

Just for the sake of conversation I'll respond to some of these notions.

Carmen; You sound to me like somebody trying to sell gas lenses..... Surprisingly enough your homepage is a welding consumables sales link :)

X-ray quality GTAW welds of aluminum are being deposited with standard collet bodies by the millions each day. The notion that Gas Lens collet bodies are "almost mandatory" for aluminum welding is so wrong as to be laughable.

Gas lenses consume more argon.... They are designed to use more argon to produce superior coverage when needed.

Jim; Raising your shield gas flow for the purpose of cooling a weld is the single most expensive way to dissipate heat I can think of. A little copper heat sink can be used over and over with 10X more heat control capability.

Next, AC powersources that provide regular sine wave current and even first generation square wave power supplies like the Synchrowave 250 or Precision Tig have a tendency to produce enough rectification and unstable arc conditions to over time melt the fragile mesh screens of Gas Lens collet bodies. I've seen numerous weld defects traced to chattered gas lens screens and the poor argon flow that they produce. At the very least, Gas Lens screens must be checked after each AC welding operation. And believe me, not very many welders are thinking about inspecting the screens on there gas lenses.

Also, The notion that a 1 inch stick out may be achieved by using a Gas Lens is an exaggeration which only politeness binds me to describe as misleading. First off nobody, (not even you) offers a gas lens that allows a stick out greater than the ID of the cup.. So while it is true that a 1 inch wide cup with a specialty gas lens can accommodate (precariously) a 1 inch stick out and a 1/2 inch cup with a specialty gas lens can accommodate a 1/2 inch stick out and a 1/4 inch gas lens can accommodate a 1/4 inch stick out, lets also consider that that specialty equipment is going to run between 40-80 bucks per unit and will increase argon consumption in the case of a 1 inch stick out to about what 50 cfh or more?

Don't get me wrong here... The Specialty cups and lens kits you sell are of excellent quality and I have used them myself and have recommend them for use on titanium where gas coverage is critical and in turban hot sections or complex castings where a long stick out was the only way to access a repair. When your stuff came on the market many craftsmen were saved alot of valuable time in that they no longer had to construct and tune their own custom cups!

But the suggestion that such equipment might be mandatory for more mundane operations just rubs me the wrong way. Especially with millions of production welds being made every day by employing simple craftsmanship and without such expensive gadgetry.

By Jim Hughes (***)

Date 09-29-2005 19:10

Lawrence,
let me get this straight, 20 CFH flowing through a gas lens is more argon than 20 CFH flowing through a regular collet body. Have you ever looked at a gas lens? If you did you would see the screens inside them. Guess what there for? To give you better coverage. Now look at a regular collet body. See the difference. I'm not talking about aluminum. I would agree with you. I don't think you need a gas lens for welding aluminum with AC. I do think it helps when using DC straight polarity. I am talking about stainless. ARGON IS CHEAP. I'm talking about when your welding stainless and you break your arc you keep your gas on for just a short time and it prevents the weld from turning black as it's cooling it.
P.S When we are welding aluminum with DC straight polarity our welders always check their gas lens. In my 23 years of working in this field I have never ever heard of a weld be rejected due to a gas lens. Remember gas lens don't make bad welds welders do.
Thanks
Jim

By Lawrence (*****)

Date 09-29-2005 19:55

Jim,

First, I think some of my snit with that sales guy rubbed off on you... Please forgive me for that.

For a given cup ID gas lens collet bodies require greater shield gas flow. Yes a gas lens will disperse gas better, no argument there.

Holding a gas lens or holding a regular collet body over a weld after the arc is broken is pretty much gonna be a push as far as cooling effect I suppose :) But i'm not sold on the idea that one collet cools a weld better than another in any practical sense. Maybe some egghead someplace has done a study on weld cooling thermal reduction via torch fed argon flow. Maybe it can be an item for a poster session at the next welding expo :)

Torch argon surely cools the hot electrodes and torch heads. Maybe it is significant and maybe your right! Gonna have to noodle this some more.

If in all those years nobody has had a reject due to a degraded gas lens why do they "always" check them :)

Every welder makes bad welds... the craftsman turns them in to good ones before they are done.

By Jim Hughes (***)

Date 09-29-2005 20:53

Lawrence,
very simple, to make sure they are getting the correct flow through the Gas lens. Gas lens 101. If it takes more argon to flow through the gas lens you need to tell the flow meter that because it can't tell the differnce.

I don't need a egghead to do a study. I know it works, we see it everyday. Stainless pipe welding 101.

Thanks
Jim

By - Date 09-29-2005 21:17

Both Jim and Lawrence are providing good details. Actually, the gas, whether using a gas lens with a screen or not, is used not really for a cooling down, although it might do that a little. It is primarily held over the completed weld to insure protection from the atmosphere. After one has welded for 10 inches, just for an example, the base metal and weld bead is hotter on the surface than when one first starts. That gas coverage is to keep out the atmosphere and allow for proper solidification rate before it is exposed to the air.

By - Date 09-21-2005 20:11

Jim,
I've been reading this thread, and would like to give my opinion. For a 1/16" filler metal, I would recommend his welding paramenters be: 11 volts and 90 Amps with 4 liter/min. shielding rate using 99.99% argon. Using a gas lens will certainly give better gas shielding, but respectfully, I'm not sure how much it is going to affect the cooling. Jim, again very respectfully, there should be no difference in welding a low carbon grade as opposed to a straight grade in the standard austenitic stainless steels. Thank you...

Chuck

By Jim Hughes (***)

Date 09-21-2005 23:53

Chuck, I think 90 amps is very high for that thin of material. I use 60 amps for 6" sch. 10 304L material, which is almost 1/8" thick. I would totally yield to your understanding of S.S material Chuck, I'm only giving my opinion from my experience. Any time I have welded thin 304 material I had a harder time keeping it from getting dark. I have never had the same problem with 304L material. I really don't why. That was why I was asking about the material he was using.

Lawrence, I was speaking about after you dry the puddle up and break your arc the gas cools the weld. Because you get better gas coverage with a gas lens verses a reg. collet body.
Thanks
Jim

By - Date 09-22-2005 00:36

Hi Jim,
Please, I concede to your expertise. I was only going on what is suggested for that wire diameter (1/16" diameter). In the Avesta Welding Handbook it says for 1/16" wire diameter the volts should be 11, and the amps should be between 80-100. Again, I would trust your judgement over what is written in a manual. But, as far as noticing a weldability difference in a low carbon grade over a straight grade of 316 over a 316L... well, I very respectfully have to disagree that there is a noticable difference. There can be as little as 0.04% carbon (max) differences in the grades, and should be no difference in the weldability. Carbon, in the standard grades of stainless steel, has been documented to not have a weldability differential over a low carbon grade compared to a straight grade. Jim, we have to remember that the "dark" color we notice is related to the heat input, but it also determines the extent of the chromium oxide layer that is burned off during the weld process. Too many poeple judge a weld by the color, and that is a big misconception.

Chuck

By Jim Hughes (***)

Date 09-22-2005 16:32

Thanks Chuck,
sometimes experience and theory don't line up. I was looking at my notes and the material (straight grade 304) had a high surfur content. 0.034. Would that affect the weldability of that material?

Also the darkness can be related to gas coverage, and other varables, such as wind, TIG torch sucking air, not just heat input.

Thanks
Jim

By - Date 09-22-2005 17:23

Hi Jim,
If I'm not mistaken, all grades of 304 stainless steel have a sulfur content of 0.03% max. I think the only difference in the two is that the straight grade 304 has a nickel content of 8.0-10.5%, and a 304L has a nickel content of 8.0-12.0%. Assuming you are using a straight 308 or a 308L welding consumable, the only difference can be the allowable carbon content. A straight 308 has an allowable carbon content from 0.00%-0.08%. The 308L has an allowable carbon content of 0.00%-0.03%. In actuallity, the chemistry can be the exact same for a 304 and a 304L welding consumable. That is the reason for dual classification. The same applies to a 304 and 304L base material. This is the reason I cannot imagine why there would be a weldability difference of a straight 304 as opposed to a 304L base metal.

Chuck

By Jim Hughes (***)

Date 09-22-2005 18:41

Chuck,
if the sulfur content was higher by the amount stated earlyer, would that have a effect on weldability?

Yes we are praying and will pray that this storm not do what the last one did. I am from Victoria, now living in Washington state. People I have talked to that live there are already leaving. They are calling for a complete evacuation of that city.
Jim

By - Date 09-22-2005 20:02

Jim,
The very minimal amount of sulfur (0.034%) over the allowable amount in a 304 or 304L (0.030% max.) should have virtually no noticable affect on the weldability. In my opinion, it is undetectable. We must realize that the effects of sulfur are to improve machinability, but it also promotes hot cracking during welding. In GTAW, sulfur does increase weld penetration, but that, too, is not a weldability issue. A 304 or a 304L, with allowable amounts of sulfur, very seldom have any detrimental affects on the welding of this grade of stainless steel. The only "bad" thing of sulfur in a 304 grade, is the slight possibility of hot cracking, but when was the last time anyone has experienced that problem with a 304 using acceptable welding procedures? The amount you stated (0.034%) is only 0.004% higher than the allowable amount of 0.030% for a 304 or 304L. This is almost a trace amount, and it is my opinion that it would not, in virtually any circumstance, have a noticable affect on weldability. On the same hand, we should never say never. Improper welding parameters can possibly punctuate the effects sulfur might present itself.

Chuck

By jon20013 (*****)

Date 09-23-2005 19:09

With all due respect to everyone's opinion in here, welding 304 or 304L is not rocket science, really pretty basic stuff! I hope COMBAT has got his brackets welded by now, lol!!! I truly and honestly don't mean this in a disrespectful manner to you COMBAT, but I can imagine a lot of this banter is way over your head?

I'm kind of curious if COMBAT was really using stainless filler metal, I am almost envisioning the silicon deposits left when using a 70 series rod. I envision this because of his statement "THE WELD LOOKS LIKE THERE IS SLAG ON IT AND IS NOT SHINY ANT ALL.

Maybe he just grabbed the wrong filler?

By - Date 09-23-2005 19:29

Jon,
Hadn't thought of that..You might have just hit the nail on the head. And, all this time I thought it took a "Brain Surgeon" degree to weld 304..Where have I been??? :-)

Chuck

By jon20013 (*****)

Date 09-23-2005 19:49

Literally laughing out loud sitting at my desk Chuck! Well, I guess we've been through the gambit of opinions, theories and suggestions now, maybe CARL will come back and tell us if things have gotten better. Eyeing the clock, now 3:56PM on a Friday afternoon, gotta stop by and pick up my dear old friend Mr. Beam on the way home, and everything should be just fine! One more hour to go and 2 weeks left before vacation time!!!! YeeeeeHaaaaaaaaa!!!

By - Date 09-23-2005 20:00

Well, I think we've just about milked this thread to death..Here's wishing you a very fun and safe vacation. Tell all "down under" Chuck says Hi..

By jon20013 (*****)

Date 09-23-2005 20:03

yep, cool, will do but that's G'day down under Mate!

By COMBAT Date 09-28-2005 18:31

THANKS TO ALL WHO HAD SOME INPUT TO THIS. I DID FINALY GET TO THE ROOT OF MY PROBLEM. I MUST SAY IT WAS THE MOST STUPID THING. SEE I TOOK MY BOTTEL TO GET TESTED AND FILLED WITH 100% ARGON. IT NEVER CAME TO MID TO CHECK WHAT I GOT. AFTER TALKING WITH A LOCAL WELDING SHOP WE TOOK A NEW BOTTEL AND TRIED IT AND THE WELDS WERE FINE. I TOOK MY BOTTEL TO HIM AND WE FOUND THAT I GOT A ARGON CO2 MIX.