[Bernard]

I am a beginner at welding. I have managed some ok welds in steel but cannot even get started with aluminium.

I have a basic AC/DC 200ST IGBT made by Stahlwerk

I cannot manage to strike a stable arc and get a weld pool.
I have a 2.4mm 2% Ceriated Tungsten (grey)
I have tried current ranging from 34A to 100A
I have tried balance set to zero = 70 - 30 and also at the extremes +5 & -5.
Filler is 2.4mm 4036
Argon gas at 8 l/m
Size 7 cup


Results look like this. What am I doing wrong?

20200217_165457.jpg (68.6 KiB) Viewed 5160 times

Electrode starts like this

20200217_165457.jpg (68.6 KiB) Viewed 5160 times

Finishes like this

20200217_165457.jpg (68.6 KiB) Viewed 5160 times

Machine

20200217_165457.jpg (68.6 KiB) Viewed 5160 times

[Poland308]

How thick is the base metal, and how large are the coupons. IE surface area. Aluminum is notorious for absorbing heat. 100 amps may not have been enough.

Edit
From the pictures it looks like you may have a gas issue.

[Mac's Crew]

I agree... with the gas issue... that looks like a #6 cup... I would double your gas see if that helps.

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[Mac's Crew]

Edit... you said it was #7. But I use the rule of 2 x cup size for a base.

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[Oscar]

Edit... you said it was #7. But I use the rule of 2 x cup size for a base.

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That's when you are looking at CFH. For L/min it's roughly the same as the cup size.

OP:

Crank the machine all the way up.
You did not disclose the thickness of the base metal.
Crank the machine all the way up.
You did not disclose if it is anodized and/or the alloy.
Crank the machine all the way up.
Your tungsten is sharpened too sharp. Try a blunt 60°included angle, with a flat on the tip.
Crank the machine all the way up.
You need to find out which "way" your AC balance is calibrated. Is more on the dial more EN, or is it more EP? Once you do do find this out, you need to set it to about 65-75% EN, or equivalently 25-35% EP.
Crank the machine all the way up.
Make sure you have an actual AC arc. Do you know what that looks/sounds like?
Crank the machine all the way up.
Show us how you assembled the TIG torch. Take out all the parts and lay them out and snap a pic.
Crank the machine all the way up.

Address these issues and/or answer these questions and we'll be that much closer to help you out.

[imita_tion]

In a similar vein to Oscar's point about AC balance, make sure your torch is connected to the negative plug. I point this out, because, well, I've done it the other way

Your welds and tungsten looked much like mine did when I goofed my polarity with the standard 30% balance on my machine.

[tweake]

Argon gas at 8 l/m
Size 7 cup

not enough gas flow. try about 15l/min.
use a blunt grind on tungsten, think crayon.
reduce stick out a bit.

[Oscar]

try about 15l/min.

I personally feel that 32 CFH is a bit too high for a #7 cup.

[BillE.Dee]

I don't see a foot pedal that comes with the machine, so, I'm assuming that the machine is triggered by the torch switch. Set at 2T you will have on at full amperage setting and off at release of the switch. In your pictures, it appears that the material is cut with a hand shear so won't be too aweful thick. If the torch is connected properly, (to the port that has ARGON gas flow) and the work clamp connected to the + you will control ac and dc at the switch marked so. Since you stated that you have made some decent welds on steel, you were set at dc. Welding aluminum you want to be on ac and keep the tungsten close to the material with a slight tilt of the torch as if you were going to push the puddle that is formed. You are looking for a shiny puddle and it will probably come about quickly. I'm not sure which direction you want the balance set on your particular machine. Try it at 9 o'clock position and if that causes the tungsten to ball in a hurry go to 3 o'clock . I tried to watch a video of that machine but couldn't understand the demonstrator.

[tweake]

try about 15l/min.

I personally feel that 32 CFH is a bit too high for a #7 cup.

yes, but keep in mind gauge may not be accurate, may have gas leak and excessive gas will still work.
once hes up and running then you can track down the gas usage issue.

[BillE.Dee]

tweake IF the gas flow is set at 32cfm, (or 16 l/m) wouldn't that make the torch whistle a tune?? thru a 6 cup?? and also cause a gas flow disturbance?

[Oscar]

tweake IF the gas flow is set at 32cfm, (or 16 l/m) wouldn't that make the torch whistle a tune?? thru a 6 cup?? and also cause a gas flow disturbance?

I think it might exacerbate the problem if there isn't a shielding gas leak.

[tweake]

tweake IF the gas flow is set at 32cfm, (or 16 l/m) wouldn't that make the torch whistle a tune?? thru a 6 cup?? and also cause a gas flow disturbance?

hard for me to say because i only use gas lens. but i use 5 cup gas lens/gas saver with ~10l/m.
with a 7 cup is doubt it would cause a problem, with a 6 maybe.
i can't quite remember but i have tried it with much higher flow rates before and have run into issues, i just can't recall how much it was,

8 l/m is to low even with a gas lens let alone a standard cup.

[Bernard]

Thank you for the advice. There is no foot pedal with the device. The material is 2 mm thick. I am melting the material right through. I have tried 15 l/m and a 6 cup. The result is better but still not like any of the videos I have seen.

I definitely have the torch and earth cable the correct way round. The machine manual says that with the balance set to zero I should have 70% negative and 30% positive. If I turn plus I should get more positive and obviously if I go minus I get more negative but the manual does not specify by how much.

I will keep practicing.
Thanks

[Oscar]

i just hope you don't keep practicing the same (wrong) way. You need to diagnose before you continue practicing. You still haven't told us if that aluminum is anodized, scrap, etc, etc. 70% DCEN sounds good, but we didn't know that at first (your equation looked 'off', lol). Lots of little things that all add up.

[Backsheddave]

Hi, guessing you have the problem sorted by now but just thought I’d put my 5 cents in. Looking at the photo, is the torch connected to the correct port? I just wondered if where you have it connected is for mma stick welding and that maybe the torch should be connected to the - port next to it? I do most of my aluminium welding with a 5 cup and the argon set at about 12l/m and seems to work fine for me. Advice I remember from Jodys videos, clean, clean, clean wipe your rods and the aluminium edges you’re going to weld with acetone or similar as this makes quite a difference to your weld pool.

[Peter69]

I've only played with my new TIG a few minutes and suffering the same results.

Some of you mentioned a gas issue, could it be the gas hose simply hasn't purged of air yet? Will play more tomorrow and try getting some more gas through the hose.

Bernard did you resolve the issue? If so how? Cheers.

[LtBadd]

I've only played with my new TIG a few minutes and suffering the same results.

Some of you mentioned a gas issue, could it be the gas hose simply hasn't purged of air yet? Will play more tomorrow and try getting some more gas through the hose.

Bernard did you resolve the issue? If so how? Cheers.

Peter welcome to the forum, I have a 25' (7.6 meters)TIG torch on my machine, I would guess if there is any air in the line it would be gone within a few seconds, all of this is assuming there isn't a leak somewhere.

[Poland308]

.00051 cu ft of gas to fill 1 ft of 1/4 inch I’d tube. 15cfm of Argon will purge 29,411 ft of said pipe in 1 min.

[LtBadd]

.00051 cu ft of gas to fill 1 ft of 1/4 inch I’d tube. 15cfm of Argon will purge 29,411 ft of said pipe in 1 min.

Ok, maybe less then a few seconds.

[Spartan]

.00051 cu ft of gas to fill 1 ft of 1/4 inch I’d tube. 15cfm of Argon will purge 29,411 ft of said pipe in 1 min.

Doesn't sound quite right to me. Perhaps if filling a vacuum, but not if actually displacing the atmospheric air in over 29,000 ft of 1/4" tubing.

Think of the delay when turning on the spigot to an "empty" (filled with atmospheric air) 50 ft garden hose laying on the ground. Upwards of several seconds before the water starts flowing out even for a 50 ft run.

[Oscar]

Don't matter OP hasn't even returned. Yet another askhole, lol. Ask a question, never come back to inform anyone. Where has common decency gone?

[Spartan]

Don't matter OP hasn't even returned. Yet another askhole, lol. Ask a question, never come back to inform anyone. Where has common decency gone?

Wait a minute, aren't you a math teacher?? Perfect man for the job. This riddle needs to be solved. Is the argon really coming out the end of my torch at over 300 MPH when using typical settings on the flowmeter?

[Peter69]

Thanks for the replies guys, I'll start a new thread as I'm getting nowhere.

Oscar I agree mate.

[Poland308]

50 ft of 3/4 inch hose holds .1515 cft of water. 1 gallon takes up .13336 cubic ft. Of 3/4 inch hose. At average pressure ( 20-100 psi). Is 23 gpm. So yes it takes a few seconds to get water out of a 3/4 inch hose. ( plus pipe restriction ft of head calculations).