The Home Machinist!

It's been a while since I practiced my welding for various reasons but it's time to get back to it. I bit the bullet and got a tank of gas and am looking for any tips or how-to's on welding with 75% argon 25% co2 gas. I have a roll of .030" wire and am going to be practicing on 14 gauge square tubing which is .083" thick.
What should the flow rate be on the gas and is teflon tape the proper stuff to use for the threaded connection to the tank?

Thanks,
Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

Hi Ed,

I haven't done much MIG with gas welding, so I don't have any specific advice there. Concerning the connection between the bottle and regulator, there should be an O ring or brass ball type connection which requires no sealant what so ever. I guess the bottle companies don't want us gumming up their valves and threads. I make sure I turn off my bottles (oxy acetyl) when not in use. I have only ever had one that leaked. Took it back to the supplier and they replaced it no questions.

From the little gas shield welding I have done, the technique is the same. You'll see, you'll have less spatter than with flux core, and like with stick welding, make sure air movement (wind/draft) doesn't blow your shield gas away from the arc. I know one thing, you're going to like having no slag to clean up. A quick shot with a wire brush/wheel and you're done.

Good Luck,
Terry

I use the cute little ball in the long pastic ice cube. I run between 1.5 and 2.5, depending on the cover needed.

When you first start out you will forget to turn the gas on, and forget to turn off when done, and all that. You will also find gas only runs out in the middle of a job, usually near the end, and the gas is expensive today compared to your pocket change.

You will find, by feel and observation, how the wire will 'blow' when you lose your cover gas. It will blow away with just a hint of rust too. You will quickly learn if you have enough cover gas or not, and my shop boxfan, is a killer for making artificial wind. I will sometimes use some cardboard taped to the weld table to still the air on a breezy day outside, it all depends. I keep the gas flow to known low limits for what I do, to conserve my time and materials.

Have fun.

_________________
Big Dave

Be Alert! The world needs more Lerts.

Ed, I seem to recall that you've been using flux-core wire, right? Doubtless you haven't forgotten to do this but - just in case - you'll need to reverse the connections (MIG gun and ground cable).

You'll like using gas,
Randy C

Randy,

Thanks for the reminder about the connections. Unfortunately I didn't get any time to practice my welding this last weekend. I had some landscaping scheduled for the long weekend and it ended up taking twice as long as I had planned. But, it usually does so it was no surprise. Hopefully after work this coming week I can finally try some welding using the shielding gas. I've got to get my welder cart built so it'll be my guinea pig for trying the shielding gas.

Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

OK, tomorrow is reserved for practicing welding with shielding gas, finally. I have a question that I will need the answer to when I get into welding my welder cart. I will be welding a piece of steel plate 3/16" thick to the square tubing which is .083" thick. How do I go about this so I don't blow a hole in the tubing? I assume I favor the thicker material with the gun. Is this correct? Would I also bevel the 3/16" plate?

Thanks,
Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

Ed,
.083" is pretty thick, you shouldn't have to much problem with it, as long as you keep moving.
It's always good to focus more heat toward the heaviest mass or thickness of metal and then
as you move forward wash back a bit onto the thin stuff and move forward again. It's easier
to do then it is to verbalize it. You might want to set up some test coupon's and get your
heat and wire feed rate and gas pressure setup first. You will do just fine, Just jump in and do it.
Ken.

_________________
One must remember.
The best learning experiences come from
working with the older Masters.
Ken.

Ya, a coupla test pieces to set up with, and then tweek it in on the job is the way we usually start out. Way less oopsies.

_________________
Big Dave

Be Alert! The world needs more Lerts.

Thanks guys! I do intend on doing a few coupons to get the settings tweaked. Here's an image of how I'm attaching the plate to the tubing. It's not structural, it's the platform for the gas tank at the back of the welder cart and a similar plate for setting the welder on.

Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

About ready to try my first coupon with the shielding gas. Here's the set-up. My plan is to tack the corners in an attempt to keep the tubing from moving as little as possible then go back and weld the four sides.

There's a number of things to do to change over to gas shielding welding from flux core.

Load solid wire.
Change polarity.
Change roller.
Change nozzle.
Hook up gas (because this is the first time running with gas).

I think that's it.

Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

First try at it failed miserably. Porosity city! Turned up the gas to try to get rid of the porosity but didn't help much. I think I need some guidance as to how high I should turn up the gas before it becomes an issue. I started out at about 20CFH per the manual and turned it up to about 22-23CFH. Not much of an increase but I don't want to turn it up too high and cause other problems. I used the Auto-Set feature which, from the reviews I've seen, actually works quite well. I think I need to turn up the heat though because penetration wasn't as good as it needs to be.

First picture is fillets I tried first. Decided it would be easier to diagnose the problem by just laying down some horizontal beads thus the second picture.

Help!

Ed

_________________
Vectrax 14x40 lathe, Enco RF-45 clone mill, MillerMatic 180 MIG.

Ed,

Try turning your gas pressure down. To much gas pressure will give you perosity and also
keep your cup about 1/4" to 5/16" off of the metal. Don't vary your cup hieght up and down.
Don't have a fan or breeze blowing in the weld area. This will make your gas move away from
the arc/puddle area.

Ken.

_________________
One must remember.
The best learning experiences come from
working with the older Masters.
Ken.