[450dualsport]

I have been doing some practice on mild steel and have actually found it more challenging than aluminum as far as getting the heat just right. What I have discovered is that when the heat seems about right, the bead is approximately the same width as the thickenss of the base metal. Is it possible to get wider beads on thinner material like 1/16" of 1/8" without over heating it?

Because aluminum flows like water, it seems that you can get whatever sort of bead profile you want. I'm just wondering if this is possible with mild steel.

Thanks.

[Otto Nobedder]

The three simple answers are:

If you "freehand", weave the puddle, or hold a larger distance from the tungsten to the puddle. If you walk the cup, take smaller but broader steps.

However, the narrower the heat-affected zone, the less you've affected the properties of the base metal. If your desire for a wider bead is purely cosmetic, I'd weld it as usual, and "wash" it to achieve the appearance.

Steve S

[450dualsport]

Thanks for the tips Steve, much appreciated! I tried a slight weave and got much nicer looking beads. The heat affected zone was considerably larger though. These were just practice pieces, but I suppose it would be wise to consider the application before making the decision to do that.

[ajlskater1]

Mild steel and stainless beads will narrower than aluminum. I really don't recomnend weaving unless you have to. Because it does make a much larger heat affected zone. Another option to laying wider flater veads on thin material is to manually pulse the foot pedal when you add rod I have found that works vety well and does not increase the heat affected zone, normally it will lessen it.

[450dualsport]

Thanks for another good tip. I'll try that next.

[450dualsport]

I found out why I have been so hit and miss with mild steel. It turns out that most of my rods were R45 oxy-acetylene rods with a few ER70S-3 thrown in. Lesson learned - don't buy welding rods at a tool store! I just bought a box of ER70S-6 rods from the LWS and they weld like a dream by comparison.

I have read that a lot of people use ER70S-2 for general purpose welding. I have read about what the difference is, but was wondering if they are a better all purpose rod than the ER70S-6.

Thanks.

[coldman]

Hi there,
I did my training at a college where they only provided ER70S-2 by popular demand from the students. My certification teacher (also a welding inspector) told me that they were nuts and we should only use ER70S-4 or ER70S-6. An old school pipe welder buddy told me that it is easy to roll silicon under your puddle with ER70S-2 and also the underside of the root pass tended to be flat. He preferred ER70S-4. ER70S-6 was good too but is more fluid and can sag in the 2G position. I took his advice and used ER70S-4 and my welding improved significantly. I never did have much problem with silicon rolling under the puddle - I think if you run hot enough this is not so much of a problem. But my root passes really improved with a nice rounded smooth bead on the inside and no suck back which was common with me previously. Have been using ER70S-4 ever since. I will never use ER70S-2 again!

[450dualsport]

How is the ER70S-4 in the vertical position? If the ER70S-6 sags in 2G it must be horrible in 3G.

I haven't tried any vertical welding with steel yet, just aluminum.

[Otto Nobedder]

How much Silicon you should use depends largely on what you're welding. Using an S-2 on a joint with a lot of impurities, or using S-6 on perfectly clean new steel each present problems.

The Silicon serves the same purpose as flux, essentially, scavenging impurities and floating them to the top of the puddle. Too little silicon for the impurities encountered, and the silicon "islands" can become too heavy to "float", becoming inclusions, and the ones that do float to the top will be very dark and hard to remove. Too much silicon for an otherwise clean weld that progresses smooth and quick makes excess silicon easy to "roll under" the puddle, again becoming inclusions, and the "islands" will be a very pale tan to nearly clear, and generally easy to remove with just a wire brush.

S-4 is a good general compromise for most work, but most local suppliers will carry the S-2 at the best price (most popular). I'm in the habit of using S-2 for almost everything (since that's what we have at work) and grabbing e70S-6 MIG wire for welding really dirty metal.

Just some thoughts...

Steve S

[450dualsport]

Thanks Steve, good thoughts and information. I have a couple of pieces of S-3 and of course my box of S-6. I am going to do a bit of experimenting....

Of course anything will be better that those R45 oxy-acetylene rods I was inadvertently using!

[Otto Nobedder]

I've gas-welded exhaust pipe with coat-hangers in a pinch... I wouldn't show you a picture if I had one, but sometimes you just "make it work"...

Steve S

[450dualsport]

I've heard that can be done, but with diffculty! I'll send you my R45s to keep in your coat closet. You never know when you might need them..

Last night I tried some S-3 and some S-6 on a piece of 1/8. The piece was rusty, but I cleaned it well with a grinder. I tried a bead with each filler - vertical up, horizontally and horizontal flat. I can't say that I noticed much difference in the way each filler welded or in the bead appearance. But then I am pretty new to this......

I will heed your advice Steve, and pick up some S-2. I'll make the decision as to which filler to use based on the condition of the material to be welded. I'm sure that as I get more experience it will become clearer.

A big thanks again to you and the others that posted their suggestions. It was all a huge help!

[coldman]

Thanks Steve for your information.
I make sure I grind off mill scale & crap away from the butts I weld inside and out. The old school pipe welders I work with don't. The bevel is shiny but they claim to have never dropped an x-ray as a result of not cleaning up the inside and outside surfaces so they save the time and consequently do more butts than me in a day. Much of the pipe we use has rust and lacquers, oil residue, any kind of crap on it and it smells bad when they weld it that way - I suppose they need the S4 and S6 in these circumstances as you say. Me - I can do without the burnt crap fumes, it can't be good for the chest in the long term.

[450dualsport]

Will the addition of helium allow you to weld thicker steel like it will allow you to weld thicker aluminum?

[Otto Nobedder]

Will the addition of helium allow you to weld thicker steel like it will allow you to weld thicker aluminum?

Good question. I've never tried.

I would think "yes", as I'll weld mild steel MIG with tri-mix (90% helium) and I love the results. At the cost of tri-mix, I don't do it too often; It's usually when I've been doing primarily stainless and have a wee bit of carbon to do to finish up, where swapping the gas is a pain in the.... hey, that rhymes.

Steve S

[450dualsport]

It sounds like there are now two good reasons to keep some helium in stock for the occasional thick piece.

Of course this brings up something else I have wondered about. What does the small CO2 component do in tri-mix? If you can tig stainless with 100% argon, would the addition of helium be of any benefit?

Good rhyme BTW....

[Otto Nobedder]

I have no real idea what the 2.5% co2 does in stainless MIG, unless perhaps the oxygen performes scavenging in it's ion form in the arc, and/or the carbon ions blend into the weld to approximate the hardness of the parent metal. Just speculation, though.

I've not really studied the metallurgy. I take Jody's "down and dirty" approach, using what works without too deeply questioning why.

Maybe Rediron will respond to this. His work requires some interesting mixes, including a TIG SS mix that's 2% O2!

Steve S

[Braehill]

@ Steve, the CO2 is there to stabilize the arc, but what I don't understand is why anyone would think it's a good idea to add Oxygen to a welding sheild gas for any type of metal. This is counter productive in my mind. We are trying to keep Nitrogen and Oxygen out of the weld puddle. Now if you add less than 5% CO2 to a stainless mix you wouldn't have much of a carbon pickup and the Oxygen would be negliable.

There's an article on a site called weldreality.com titled mig gases that explains the positives and negatives of gas mixes better than I can. It's well worth the read if you're buying high priced tri-mix gases.

Len

[450dualsport]

Weldreality is an interesting read. Thanks for posting it. I think there is probably quite a bit of truth to what he was saying. As with anything, I think a lot of new products provide more benefit to the shareholders and CEOs than they do to the end user.

All the more reason to just follow the "down and dirty" approach....

As a side note here, the Tip Tig setup was interesting.