Argoshield light or heavy?

[Ali]

Can't say you didn't all tell me so , but those little bottles run out bloody quick don't they?! Got a big CO2 cylinder already but after experimenting with some little bottles of CO2 / Argon mix, I am well impressed with the result and now want a big one (ooo err!). Most suppliers seem to offer a 5% or 20% mix (or Argoshield Light / Heavy - whats the difference? I will be welding mostly bodywork, but upto 3mm (Land Rover chassis - holier than the pope himself).

P.S. Any feedback on the gas supplier that advertises 'medium' size bottles with a £40 deposit on the home page? (Adams gas) Or any other suppliers who will deliver that anyone can recommend?

Thanks in advance for any advice, as always

 

[shenion]

Argoshield heavy is almost the same as the 80/20 disposables.

Stick with the light, it will be easier on thin metal.

Although, i do prefer the profile of 80/20 (symmetrical top/bottom at 100% penetration), it is harder on thin metal.

 

[Ali]

Although, i do prefer the profile of 80/20 (symmetrical top/bottom at 100% penetration), it is harder on thin metal.

Huh?

 

[shenion]

Huh?

Hard to see but a cut through with 80/20 and weld on top and bottom are the same shape.

 

[Drains]

Argoshield light for up to 3mm, fine. If you're going a wee bit heavier, Universal will do nicely.

 

[Ali]

Will my Co2 be OK for the thicker stuff? What is Univeral?

Cheers for the pic Shenion, thats more or less what I was getting with the little bottles - starting to realise how sciency this welding business is now. (Wish I'd paid more attention in Chemistry now, spent most of my time trying to turn up the gas supply on the bunsen burners in the hope that Mrs Turpin would set her beard on fire. )

 

[shenion]

CO2 will work up to about 4mm, then I find it just gets too messy. It also depends on how good the wire feed is as CO2 has a smaller speed range.

 

[Vanny]

I'm glad someone else asked the question first. I use argoshield light because thats what i've got, now i know what the difference is i'm happy i've got it (though a full cylinder is anything but light!)

 

[Drains]

Ali, Universal is halfway between Light and, er Heavy. It's an all rounder, so ideal on the middle ranges, not as good as light on light, not as good as heavy on heavy.

TBH, you can use CO2 on everything if you have a good machine/ are used to it. I used CO2 for years (in the old days). The main requirement was a heater on the bottle reg to make sure the co2 was warm enough to wok, and didn't freeze the pipes.

Co2 was totally standard industry practice on the highest quality m/s Mig welds. It can be very spattery, far more than argon mixes. Shenions problems re "messy" over 4mm may be as much to do with going into globular transfer. I'd imagine it would improve a little over 28-29v or so?

 

[marknotgeorge]

I've just taken delivery of a cylinder from Adams gas. Ordered it Monday afternoon, and it arrived today, thanks to a cheery courier who told me 'It's heavier than it looks' (it came wrapped in a cardboard box). 5% CO2, 3% O2 (I think), in Argon. Connected it up to my Cosmo with the regulator I bought from Weldequip months ago, and it all works ok. It gets my recommendation, although the courier charge is a large proportion of the cost, so I'd look for a local supplier first. I did try googling 'welding gas Derby', but kept coming up posts on here by some idiot blithering about some spreadsheet...

 

[runnach]

TBH, you can use CO2 on everything if you have a good machine/ are used to it. I used CO2 for years (in the old days). The main requirement was a heater on the bottle reg to make sure the co2 was warm enough to wok, and didn't freeze the pipes.

Si, serious Q, I have only used CO2 once, and this was for a short spell (in the older days) when working at a local company when my time was just out. I remember the heater very well, I thought the heater was there to turn the CO2 to vapor prior to reaching pressure gauge and business end?

Cheers.......

 

[shenion]

Odd, I use my CO2 bottle with no heater. It does not get cold at all.

I could see it needed in a production environment, but with the duty cycle on DIY welding, I don't see any need for it. It is set up for gas out (no dip tube.)

 

[Drains]

Si, serious Q, I have only used CO2 once, and this was for a short spell (in the older days) when working at a local company when my time was just out. I remember the heater very well, I thought the heater was there to turn the CO2 to vapor prior to reaching pressure gauge and business end?

Cheers.......

Quite right T, it was indeed to ensure the Co2 was vapour, not icy cold liquid!
In more recent years (10 years back) I was doing a lot of mig with a nasty little set and a co2 bottle. The welding seriously suffered as a) the gas got cold and b) the plant got hot. Utter PITA.

Note - this was a pub gas size bottle, used over hours. I'm sure a larger bottle wouldn't suffer so.

Why are the dip tubes used? Can anyone explain?

 

[shenion]

Dip tubes are used to fill paintball gun bottles where you want liquid transfer.

 

[Ali]

CO2 will work up to about 4mm, then I find it just gets too messy. It also depends on how good the wire feed is as CO2 has a smaller speed range.

Hmm. I was sort of under the impression that a CO2 / argon mix was good for thin stuff (thats what it says on the little Clarke bottles anyway), but it would give you better results than CO2 with anything upto a certain thickness - whereupon straight CO2 takes over. Are there any rough guidelines - say I had a bottle of both (which I will, hopefully ) what thickness would the Co2 take over?

And what do you mean by CO2 having a smaller speed range - ie., the speed I move the torch? Tried butt welding some 1mm on 80/20 the other day at 30 amps and had to move lightening fast to avoid blowing a hole! Makes it proper hard to do that zig zaggy motion that is so easy with the thicker stuff! (Can you tell I'm still learning Thanks for patience all! )

 

[runnach]

Just had a wee look into my weld book library Si (plenty here if you wish to borrow sometime)

There are two types of CO2 gas, the first type allows CO2 to come out as a gas which may contain moisture (hence your pita effect) the second type is called siphon cylinder. It draws CO2 from the bottom of the cylinder, avoiding the problems of unwanted moisture. To prevent the regulator from freezing when the liquid CO2 expands into gas, an electric heater /vaporiser unit between the the cylinder valve outlet and the regulator. These are quotes BTW.

So basically Si, the dip tube sucks up the liquid CO2 from bottom of cylinder, keeping it separate from the top 1/8 which is gaseous. Easier to understand with the help of a sketch drg mate. For the record and, not sure if colour coding still exists? CO2 cylinder with a white stripe, represents liquid CO2, the white stripe representing the siphon tube.

 

[Drains]

We live and learn!

Thanks T. You're in the right job you know!

 

[shenion]

At higher currents, the arc becomes unstable with more spatter with CO2. I could do a near spatter-free weld with CO2 with my Clarke on 1mm.

The gas mix is critical for the transfer mode. Using the correct gas can change the current points that short arc, globular and spray transfer modes occur. Pulse mode MIG can extend it even further.

Short arc will work up to about 150A with just about any gas.

At about 170A it will try to go into globular transfer with high argon levels. Here is where 75/25 Ar/CO2 is best as it keeps it in short arc mode.

Above 170A using spray transfer, low CO2 is used to keep the transfer from switching down to globular transfer. Here, 5-8% CO2 and no O2 is common. Spray transfer is used in production as it has the fastest weld speed. It does not work well on positional welds though.

As an example, I worked with a guy that was doing huge storage containers out of 3/16" steel (8' x 8' x 16'). He was welding at 175A and was all positional. Using 75/25 kept he transfer mode in short arc. If he had used a higher arginmix, it would have changed to globular or spray transfer and he could not do vertical or overhead welding.

As far as speed, On my little Clarke with power setting at 1 and Ar/CO2 mix I could get a good weld 'buzz' with a wire speed from 2.5 to 3.5. With pure CO2 it was only good from 2 to 2.5. As CO2 has a lower electrical conductivity, the arc length between the times the wire touches the weld pool is shorter. It makes it more sensitive to wire speed (also lowers average current at a specific voltage.)

 

[Ali]

At higher currents, the arc becomes unstable with more spatter with CO2. I could do a near spatter-free weld with CO2 with my Clarke on 1mm.

The gas mix is critical for the transfer mode. Using the correct gas can change the current points that short arc, globular and spray transfer modes occur. Pulse mode MIG can extend it even further.

Short arc will work up to about 150A with just about any gas.

At about 170A it will try to go into globular transfer with high argon levels. Here is where 75/25 Ar/CO2 is best as it keeps it in short arc mode.

Above 170A using spray transfer, low CO2 is used to keep the transfer from switching down to globular transfer. Here, 5-8% CO2 and no O2 is common. Spray transfer is used in production as it has the fastest weld speed. It does not work well on positional welds though.

As an example, I worked with a guy that was doing huge storage containers out of 3/16" steel (8' x 8' x 16'). He was welding at 175A and was all positional. Using 75/25 kept he transfer mode in short arc. If he had used a higher arginmix, it would have changed to globular or spray transfer and he could not do vertical or overhead welding.

As far as speed, On my little Clarke with power setting at 1 and Ar/CO2 mix I could get a good weld 'buzz' with a wire speed from 2.5 to 3.5. With pure CO2 it was only good from 2 to 2.5. As CO2 has a lower electrical conductivity, the arc length between the times the wire touches the weld pool is shorter. It makes it more sensitive to wire speed (also lowers average current at a specific voltage.)

Wow. Off to Amazon to buy a welding book so I understand all this clever stuff!!

 

[V8-108]

Wow. Off to Amazon to buy a welding book so I understand all this clever stuff!!

That makes 2 of us!!

Neil