to flux or not to flux?

[W8BYA]

This has been very helpful all the way around and I wanted to say thank you. One last question, I have decided when the money does becomes available and I do get a "MIG" it will be a bare wire system. WAY back in the 70's when I was taught how to weld we used pure Argon.......I now hear of CO2 as well....maybe even a mix of inert gases are best to use. Is there one gas that works well in all cases or are certain gasses or a mix needed for certain metals etc?

 

[kenmac]

This has been very helpful all the way around and I wanted to say thank you. One last question, I have decided when the money does becomes available and I do get a "MIG" it will be a bare wire system. WAY back in the 70's when I was taught how to weld we used pure Argon.......I now hear of CO2 as well....maybe even a mix of inert gases are best to use. Is there one gas that works well in all cases or are certain gasses or a mix needed for certain metals etc?

I use 75/25 mix. you can use straight argon. I have done it many times.
I have found using pure argon provides a little more splatter and less penetration when welding at the same temps as 75/25 mix gas
I don't care for flux core

 

[kenmac]

No one ever looks at the stamped date upon refill. Never had to pay for a re-cert. Simple swap an empty for a full tank. I suppose it is baked in to the cost. The tank I owned is in someone else's shop. I imagine when tanks 'expire' they get pulled aside, re-cert'd and put back in the population.

they do around here. Had mine filled about a month ago and purchased a argon tank for my tig unit. The re cert test cost me $25.00
Also had my small nitrogen tank filled. they did that while I waited

 

[W8BYA]

I use 75/25 mix. you can use straight argon. I have done it many times.
I have found using pure argon provides a little more splatter and less penetration when welding at the same temps as 75/25 mix gas
I don't care for flux core

Great info, TU !

 

[Fallon]

No one ever looks at the stamped date upon refill. Never had to pay for a re-cert. Simple swap an empty for a full tank. I suppose it is baked in to the cost. The tank I owned is in someone else's shop. I imagine when tanks 'expire' they get pulled aside, re-cert'd and put back in the population.

They did on my argon tank on last fill. Was just a $10 fee & they swapped it out for a full one. Well also a $50 fee as I took the opportunity to upgrade to a bigger tank.

My local home brew shop wont fill my 5# tank (for soda carbonation) as its expired & they only fill. No swapping or rectifying there. They recommended several other places that do. Irionically the closest is a liquor store.

It's not a big deal or hard, but is the cost of owning vs renting/leasing. It's a pain, but if you've ever seen the destructive power of compressed gasses, even inert ones, it's well worth knowing your & others tanks arent ticking time bombs. Pretty much litterally.

 

[otlski]

Somewhat of a tangent here, but what exactly to they do when they re-certify a tank and who is qualified to do so? Do they run a bore scope down inside, magnaflux, proof test, eyeball it, shake holy water, check serial numbers? What?

 

[W8BYA]

Somewhat of a tangent here, but what exactly to they do when they re-certify a tank and who is qualified to do so? Do they run a bore scope down inside, magnaflux, proof test, eyeball it, shake holy water, check serial numbers? What?

I don't remember all (most) of the details as it was many years ago but I asked that question when I 1st bought my O2 and Acetylene tanks. It was a pretty sound process with no BS performed by companies certified & accountable for the task. I remember tanks being X-Ray'ed, visually inspected, pressure tested to more then rated numbers to ensure no leaks etc. He also said he gets a chuckle when people insist on "new" great looking tanks because knowing what he knew he would not hesitate trusting and owning tanks that were well over 50 years old. When needed the insides get changed, valves replaced, etc, etc. They may look used on the outside but like a book that is just the outer skin of another tank and you cannot judge the insides by what you see on the outside. At that point I stopped worrying about getting a pretty newly painted tank when I did an exchange.

 

[Fallon]

A "hydro test" of technically hydrostatic test. They pull the valve off & do a visual inspection. Then they put the tank in a vat of water they then fill the tank with water (well maybe before putting it in the vat so it doesnt float). They then note the vat water level, then pressurize the tank to somewhere over the rated tank pressure. They then note the water level in the vat again. How far the water level in the vat raised indicates how much the tank stretched when it was pressurized. That volume needs to be within certain specs to pass. If its below a certain spec they stamp them with a + sign next to the hydro date stamp & you can slightly over fill them. If the tank stretches to much, its scrapped.

As water or other fluids arent compressible there isnt much energy to explode if the cylinder ruptured during testing, at least compared to if it was a gas. The vat & the water in it helps disperse any energy in the event of a failure too.

 

[Tractor Seabee]

No one ever looks at the stamped date upon refill. Never had to pay for a re-cert. Simple swap an empty for a full tank. I suppose it is baked in to the cost. The tank I owned is in someone else's shop. I imagine when tanks 'expire' they get pulled aside, re-cert'd and put back in the population.

Mark, Pacific where we go (I assume you do) always checks the date. That is why I had to pay the re-cert I mentioned earlier in this thread. For an obvious damaged valve; there is a cost for that also. The valve is pulled out and checked when the re-cert hydro test is done. Different process for acetylene due to the filler and acetone. Not sure how that is done. I have used 2 other WS here in Bremerton in the past, and they all have the same process.

Ron

 

[gsganzer]

I'm planning to try some dual shielded. I think it might be the best of both worlds allowing me to deal with some less than clean metal while minimizing splatter and maintaining appearance. I have a stick welder for doing outdoor work (fencing, corrals etc.), but would use the wire feed for shop projects like building deer feeders, blinds etc.