Which gas to use for welding a stand?

[evandena]

Hey guys,

So I picked up a little Lincoln Weld-Pak 100 on Craigslist. I want to take the time to teach myself how to weld, so I can work on a brew stand.

It came with the gas conversion kit, so all I need is a cylinder. A lot of people recommend a 75/25 for general MIG welding. That's fine, but I'd have to rent a cylinder, and this would only be used for hobby welding.

Now, I have a full 20lb tank of CO2 in prep for kegging, which I could borrow for welding. I think I'll be learning on cheap angle iron, eventually getting to 2"x2", 1/8 square stock.

Would the CO2 be too hot and harsh for me to learn and build a stand on? The 75/25 might be better, but is it worth the extra cost when I already have CO2?

Thanks!

 

[user 4295]

Without a doubt, if you want to learn how to weld, use the argon/CO2 mix. Here's a great write up that may help you decide. I know it will require you to buy another tank, but I think you'll find it difficult to learn to weld well using CO2 alone.

Weld Gas Comparison

 

[petrostar]

I'm actually building my Brutus this weekend using the 2" tube stock. I have a forum about it. I'm using a 90 amp flux wire welder with .035 Lincoln wire. 40 ft of that tube is really cheap btw. I had zero experience as of yesterday and am now welding like a champ. My suggestion, just go for it and make sure your joints are really clean.

 

[n2fooz]

There is no substitute for using the gas. 75/25 not pure CO2.
Top is with gas, bottom is without...

 

[Berniep]

There is no substitute for using the gas. 75/25 not pure CO2.
Top is with gas, bottom is without...

Straight co2 will be somewhere between those two pictures. It has more splatter than the mix but not as much as the flux core wire.
It also has more penetration but unless you are welding less than 1/8 inch stuff it wont be an issue.
Actually looking at the bottom weld more it looks like a very fast unsteady run, maybe at the wrong polarity. You can get much better welds with flux core than that, just takes some practice.
I say try the co2. A little wire brush action and maybe some anti splatter spray before and you will be in business.

 

[OneHoppyGuy]

2 x 2 x 1/8" is way overkill and will way a ton (figuratively).

 

[Goose5]

CO2 is just fine. That's what I learned with while in school. The weld mix runs smoother yes, but straight CO2 you get deeper penetration.

 

[OneHoppyGuy]

Most stands are made of thinner material (.065) so we use Argon/CO2) to keep from burning through.

 

[evandena]

Most stands are made of thinner material (.065) so we use Argon/CO2) to keep from burning through.

What's the sweet spot for stock size?

 

[OneHoppyGuy]

There aren't many choices for thickness. All our stands are .065. For hr we use 1.75 square stock and 1.5 x 1 for lower rails. 1.75 SS is more expensive than 2 so are SS stands are 2 x 2 and 1 x 2 for lower rails.
No center brace is required up to a 72" span. In, fact, a vertical brace does little to prevent sagging and is just a waste of steel and time. Angled braces on the back side are superior to a straight rail.

 

[evandena]

There aren't many choices for thickness. All our stands are .065. For hr we use 1.75 square stock and 1.5 x 1 for lower rails. 1.75 SS is more expensive than 2 so are SS stands are 2 x 2 and 1 x 2 for lower rails.
No center brace is required up to a 72" span. In, fact, a vertical brace does little to prevent sagging and is just a waste of steel and time. Angled braces on the back side are superior to a straight rail.

Good info, thanks.

One more question, are argon and co2 tanks interchangeable? What tanks do mixes go in?

 

[n2fooz]

Good info, thanks.

One more question, are argon and co2 tanks interchangeable? What tanks do mixes go in?

Airgas swapped a CO2 tank for a 75/25 tank for me. They will charge $20 if your tank is out of date. Also this is only if you have a steel tank and not aluminum.

 

[evandena]

There aren't many choices for thickness. All our stands are .065. For hr we use 1.75 square stock and 1.5 x 1 for lower rails. 1.75 SS is more expensive than 2 so are SS stands are 2 x 2 and 1 x 2 for lower rails.
No center brace is required up to a 72" span. In, fact, a vertical brace does little to prevent sagging and is just a waste of steel and time. Angled braces on the back side are superior to a straight rail.

Couple more questions...

1) What do you use to cut your square stock? I'm on the fence about buying a cutoff saw, but they're hard to find used.

2) What do you pay for your stock? I called two local places, same price: $32 for 24 ft for 1.5 square.

 

[OneHoppyGuy]

We use a cut-off saws. They're messy and require a lot of post cut clean up. I have wet dreams about cold saws (pun intended).
We're moving to band saws this year.
$32 for 24 ft is a pretty good price (better than California prices). 24 feet is an odd size, usually it comes in 20 foot lengths.

 

[petrostar]

Chop saw will give you a more square cut but bandsaw more clean in my short experience.

 

[Bobby_M]

Caveat: I suck at welding. I use co2 because I have a tank full. I don't weld often enough to dedicate a mix tank.

 

[n2fooz]

Airgas is willing to swap for a mix tank, they would probably swap back to CO2 after you are done.

 

[phoenixs4r]

Just use flux core wire for mild steel..... I don't understand what folks have against it.... why go through the hassle of disconnecting or swapping tanks for hobby welding when you can just fire the thing up and go?

 

[evandena]

I ended up getting an Argon mix. Renting it for ten cents a day. I can do that.

 

[Huaco]

2) What do you pay for your stock? I called two local places, same price: $32 for 24 ft for 1.5 square.

I got (2) Sticks 20' each of 1.5x1.5 square tube for $30... of course, I work at a metal fabricator and these two sticks were included in with an order of about 30,000 pounds of steel!

 

[day_trippr]

Just use flux core wire for mild steel..... I don't understand what folks have against it.... why go through the hassle of disconnecting or swapping tanks for hobby welding when you can just fire the thing up and go?

Have you ever done any MIG welding? It's so much cleaner, no shower of sparks, virtually no smoke or spatter, and imo easier for noobs to produce a good weld than flux core...

Cheers!

 

[OneHoppyGuy]

nah... go TIG

 

[phoenixs4r]

Have you ever done any MIG welding? It's so much cleaner, no shower of sparks, virtually no smoke or spatter, and imo easier for noobs to produce a good weld than flux core...

Cheers!

I've done stick, mig, tig and the flux core you build bridges with. I'm not saying flux core via a 110 buzz box is the best, but gas is not necessary when you can wipe most of that **** away with a wire brush.

 

[phoenixs4r]

nah... go TIG

learning TIG is the best experience ever, when you mess up you shock the **** out of yourself, and you tend to learn quick!

 

[day_trippr]

I've done stick, mig, tig and the flux core you build bridges with. I'm not saying flux core via a 110 buzz box is the best, but gas is not necessary when you can wipe most of that **** away with a wire brush.

Whatever, I didn't say "best" or even "necessary"...

Cheers!

 

[evandena]

nah... go TIG

Have you tried cutting square stock with a portable bandsaw, such as one of these?
Amazon.com: portable band saw

 

[evandena]

Screw it, I picked up one of these while they were on sale. Decent reviews too.
http://www.farmandfleet.com/product...ef=/catalog/find.aspx?t=chop+saw#.Tx5O8jES37Q

Now it's time to order some steel.

 

[Airplanedoc]

Have you tried cutting square stock with a portable bandsaw, such as one of these?
Amazon.com: portable band saw

Portabans are great for many things under 4" , but it takes some practice to make a straight cut.

 

[Misplaced_Canuck]

Here's my 2 cents:

I was welding a set of trailer ramps for a neighbor, made from angle-iron (I think 1/8"). I was using my CO2-Argon mix, having an easy time at it, and I ran out. I pulled out my keg CO2 tank, and started welding with that. The first thing I noticed was that I had to bury the nose DEEP into the weld to keep a decent weld, but it still worked OK.

I handed the ramps to him. A few weeks later, I noticed that one of them was bent... Turns out he had tried to load up his 25HP John Deere on the trailer using the same ramps. Oops. The welds held up though.

MC