[sausageroll]

Hi Everyone,

I decided I need to make some actual progress with my welding learning, so I got a local metal shop to cut me 120 3x3inch squares of aluminium, 3mm thick.

This is so I can just weld them to each other, or weld them into cubes and can practice various types of joints etc etc.

So a few questions. Can anyone recomend some settings and setups to start with? This is what I have currently:

1.6mm white tip tungsten
Using a CK gas saver gas lens
Current is 130a but I use the pedal
Freq is 250hz
Balance is set to about 35-40 percent

Currently not using any pulsing

I am managing to get some good joints this way, but occasionally I do a tack or something, and it spits and splutters and I take the mask off, and the tack has some black soot around it. Im guessing this is caus of dirt in the metal surface? The metal had an oil on it from the shear, so I have been cleaning with a degreaser, then a contact cleaner and then using a stainless grinder brush to get the surfaces clean before welding. Is this enough?

Also I had a question about my tungsten, obviously with AC welding, the tungsten gets eaten up, unlike DC. When my three inch weld is done, what should my tungsten look like? Sometimes I get a ball on the end and it goes a shiny blue. Sometimes its just this horrible blunt powdery grey. I asked another question on this forum about tungstens after welding and everyone said argon postflow is the answer. Silly question here, but is the same true of ally?

How far should I keep the tip from the puddle? I have dipped a few times and made a mess this way.


Thanks for your help,

Pete.

[Otto Nobedder]

Unless your balance control is "backward" (I've seen that on some "made in China" welders), I'd suggest 70-80% balance (My personal preference).

I (personally) like your setup.

The "ball" on your tungsten should be shiny silver and only slightly fatter than the tungsten it's on. You didn't mention your gas flow and post-flow settings.

For tacking, I like to turn the machine all the way up, and nail my tacks quick and hot, and feed rod until they're full as I tail off. Again, a personal preference.

Steve S

[sausageroll]

Hi Otto, thanks for your reply.

I have just had a look at my gas flow, currently running 15CPH (atleast thats what it says on the ball gauge thing)

Post flow is set to about 3-4 seconds, although im impatient and sometimes just take the torch away as soon as I stop the arc. I welded scratch start for ages, and this was the only way to stop the arc on the machine I had, so I just got so used to pulling the torch away from the work as soon as the weld stopped. Im guessing the post flow would help keep the electrode clean?


As for the balance, I have checked in the manual and the low end of the scale (my scale is 30-70) is penetrate, and the high end is clean. Its a pretty decent machine, made in the UK by a british company called R-Tech. It was not cheap, although not as expensive as some others. It seems very good really and was well reviewed. I think my scale is backwards so your 80 percent is equivalent of my 20 percent, which mine wont go to. Maybe I should try sticking it on lowest it will go, 30 percent.

Is it worth cleaning the material with acetone or something as well as a degreaser?


Thanks,

Pete.

[motox]

sausageroll
i would skip the degreaser unless its super super grungy stay away for contact or brake clean
and use a stainless brush without pressing down to hard. then acetone on coupon and filler rod as well.
craig

[GaveUpOnTV]

Make sure that the stuff that you are cleaning the oils off with IS NOT CHLORINATED. UV light (Tig puts out a lot) will turn chlorinated solvents to phosgene, which is extremely poisonous. A lot of welders have died in closed areas when chlorinated solvents are present.

[Otto Nobedder]

Pete,

I always set my balace toward "penetration", so according to your information, you're doing it right (or at least the way I'd do it).

Crank that gas up. Try the same weld at 35 CFH, and compare the results.

Usually, a quick hit with a wire wheel is more cleaning than aluminum requires, unless it has grease/oil on it (like an extruded part.)

Steve S