[RamboBaby]

A month ago I tested for a kitchen fab shop and failed the test miserably. You guys were very helpful with some of your tips. I went back today and failed it again but not so miserably this time.
I can't really practice scratch start on my machine because it's lift tig or high freq. Lift tig feature does not work either. It will scratch off about 20% of the time when set on lift tig but mostly it just sticks. I watched a couple of videos on scratching off and only stuck it one time today in roughly 30 starts so I think that I have that part down.
I asked the shop foreman what amperage they generally weld at (it's almost all 16 gauge) and he told me 70 amps but that I was welcome to reset the machine. That stuff got cooking in no time flat and I didn't have a tig finger on so I had to choke way back on the torch which resulted in a weld that looks like I had Parkinson's disease.
I have six pieces of 16 gauge that are 2"X10". I want to be able to go back in there and pass their test but I don't have the luxury of messing up these few practice pieces.
Tacking from he center of the joint out to the ends. I know that I'm gonna need to take my tig finger in when I go back. Would lay wire work better for this than dabbing? Back and forth like pipe welding? How fast to travel?
Waiting on your replies before I go and destroy what little metal that I have left to practice on. Anyone have a video link on how to weld stainless that is this thin when the torch is this hot? I just wanna be able to do it their way.
Thanks guys.

[Rick_H]

What type of joint? What position? Backer or open if not a fillet

[RamboBaby]

Flat closed butt and flat t-joint. No filler on the butt weld. I pony clamped a piece of 1/8" X 1" X 2" aluminum tubing to the back of the t-joint. I took the tubing and clamps in with me and they didn't seem to have a problem with me doing that.
I don't know if I'll be willing to show my face around there agin if I flunk the test a third time.

[Poland308]

As long as they see improvement I don't think they will mind testing you again. It shows your working at getting better on your own not just begging for a job.

[Rick_H]

Here just whipped these up for ya..

Maxstar 150 STH, 1/16" tung, CK gas saver, 70amps

16g 304L Stainless, butt weld with alum backer, I moved fairly quick straight pull

16g 304L Stainless, fillet weld, dabbing (didn't sugar the backside on either)

[RamboBaby]

So you just do a couple of inches at a time? They're giving me joints that are about 12" long. The first time I tested they told me that they sometimes do runs that are 30 feet long.

[Rick_H]

So you just do a couple of inches at a time? They're giving me joints that are about 12" long. The first time I tested they told me that they sometimes do runs that are 30 feet long.

I just stopped there, with the thin metal if I were to continue it would warp and pull around.. you could stitch it across in 1.5"-2" sections then go back and fill those in. At that point you have starts ands stops to worry about.

Depends what they are asking for with the test....I would weld a 16g fillet 36" long, would it stay straight, most likely not

[RamboBaby]

I stitched it in about 2" sections, then filled in the gaps a few minutes later. Apparently I'm moving way too slow because I got very little color other than gray and silver. Can't figure out why some of the sections were silver because my travel speed didn't increase.
The pieces that they had me test on were about 6" X 12" so it really wasn't gonna warp too much if I gave it a minute to cool. That's definitely not the case with the practice pieces that I picked up today.
How many seconds each did it take you to do those short runs?
What's your gas flow set at?
Edit:
Torch angle? Stickout?
I've been using about 5/8" stickout, 1/16" tungsten on a #4 cup with about 8 cfh because I'm getting low on gas with no money to buy more.
Looks like you're pushing about 3X as much wire into the puddle as I have been. I'll have to try that.

[Rick_H]

Do you have Instagram, I took a small video... I even did this lay wire instead of dab

I welded about 4" in 40 seconds or so with 3/32" filler, I got lit up and started moving and didn't stop. I tried to slow up and blew through. PERSONALLY Id run lower amps, but I wanted to stay at 70amps to keep this conversation consistent.

Stick out is around 3/4" because of what I am doing and the large lens I have on, 25cfh... I don't think 8 cfh will allow good gas coverage. Angle is right at the joint, nearly 45° with a slight push angle.

[RamboBaby]

I just installed instagram. Glad I didn't need a Facebook account because I deleted that months ago.
I only have 1/16" 308 & 309 & 1/8" 309 to practice with. They gave me 1/16" rod for the test and I'm just assuming that it was 308 because the parent material is 304.
8 cfh on the #4 cup was to save gas. Last job wanted to use me as a cleanup man for that junk yard they call a fab shop and I didn't sign up to clean 20 years of clutter @ $10/hr. Gotta get another job before I can buy more gas. I can turn it up for a few short runs but I gotta save some to fix my buddy's ATV.
Where do I find the video on instagram?
On the test they're using a #6 cup with what sounds like between 20 & 30 cfh. I doubt there is a gas lense in there (I didn't look) because of the way the gas flow sounds. It's as loud as I've ever heard gas flow from a tig torch.
Scratch start with a knob on the torch to turn on gas flow.

[Rick_H]

Search for RNHFAB

I have to finish a few things up then Ill grab some more scrap and a small cup and rock a good video out for ya 1/16" filler

[RamboBaby]

Thank you brother

[Rick_H]

New video posted, hope that helps....

[RamboBaby]

It do. Thanks.

[RamboBaby]

14g mild steel practice cause I don't have much stainless left. 18" of weld, 90 amps, 4T peddle switching. Stops & restarts were at 6 1/2" & 13 1/2" respectively. There's a little bit of undercut in a couple of spots where I tried to reposition my torch hand without coming off the juice.
I'm really pissed at myself for blowing that test a couple of days ago.
He only real problem that I'm having with the stainless now is coloring. I'm not sure if it's not enough gas flow or just hanging around for too long. I tried cranking the flow up to 20cfh and the color got worse. Afterward I noticed that my welder's cooling fan was blowing on the joint.

[HELacey]

I don't see 16ga stainless and anything more than about 45 - 50 amps. It'll allow to slow your travel speed just a bit and not have your puddle out of control, but still enough so that you can move along the joint.

I work with a lot of stainless for poultry (we do lots of contract work for the local tyson plant) and I got lucky as all get out when I tested for my job. I hadn't really welded a whole lot of stainless before hand, and I was still in school at the time as well, but I made sure that day I was in the dime layers club.

The faster you can get that puddle established and start moving, the better. Stainless is super sensitive to heat input. The coefficient of thermal expansion is 1.5x that of carbon steels, and the fact that chromium is reactive to heat, and when it gets hot it get bombarded by oxides like crazy! Proper shielding will also go a long way as does a tight arc length. I'll run stainless on the edge of nipping my tungsten in the puddle, and always with a gas lens.

Best advice I can give is just keep goin for it

[RamboBaby]

I bought a cheater lense to take that test. Turns out that the cheater was as much of the problem as anything else. When I took it out at the house this is what I get:

BILu3oGhUVU.jpg (35.73 KiB) Viewed 1099 times

I know it is a little wobbly but I had to move it pretty far away from me because I was taking video of the weld.

[HELacey]

Your consistency is on the way there, but your heat input is way too high. You need to either turn downs the amps or move faster across that joint. That dark burnt purple is the hexavalent chromium burnt off which defeats the purpose of stainless to begin with. I'd try to move along the joint faster.

[RamboBaby]

That's about as fast as I can move. My hands aren't suited to feed with my thumb so I use my first and second fingers to extend the wire into the puddle. This causes problems with missing the mark if I don't feed slowly because the filler is moving in an arc instead of a straight line. I guess I'm just gonna have to turn the heat down.

[exnailpounder]

From the looks of that weld, you are weaving your torch. I can't really tell from the pic but if thats only 14ga. you don't need a weld that wide so weaving to get a wider and fuller bead is smoking that thin metal. It looks like weaving because you don't have that stack a dimes look. Like I said, I can't really tell from the pic so tell me to shut up if I'm wrong but thats what I see from reading that weld.

[RamboBaby]

From the looks of that weld, you are weaving your torch. I can't really tell from the pic but if thats only 14ga. you don't need a weld that wide so weaving to get a wider and fuller bead is smoking that thin metal. It looks like weaving because you don't have that stack a dimes look. Like I said, I can't really tell from the pic so tell me to shut up if I'm wrong but thats what I see from reading that weld.

Yes sir, I have been weaving to compensate for the fact that I have never been able to stab the rod straight into the puddle. I pretty much learned how to tig with aluminum because how I feed the rod into an aluminum puddle didn't matter. Because of your post I just went out to the shed and tried feeding with my thumb. Apparently I have developed a much lighter touch now and feeding with my thumb went just fine. As a result the rod is now feeding in a straight line rather than an arc. Now I'm gonna go try actually welding like that and I'll post pics of the results. Thanks for the "Eureka" moment!

[exnailpounder]

You bet bro! I can't feed rod worth a damn so I had to get good at hiding my starts and stops. Go get 'em!

[RamboBaby]

Brother!,
I owe you a few pitchers of beer at least!
I started out with my same old BS and then asked myself, "Self, what in the hell are you doing?".
Then I straightened up and just look what happened!

[exnailpounder]

YOU NAILED IT! Good color too! Bravo! There is no shame in starting and stopping. We all strive for excellence but in the real world sometimes it's not completely possible. I wish I could do big long runs but I never get the kind of work that requires long runs so I concentrate on making my short runs look good and my start/stops almost unnoticeable to the untrained eye.

[RamboBaby]

Now how in the heck do I do autogenous tacks? I just can't seem to do it without burning through and those big globby filler tacks look like total crapola!