Ask your WELDING questions here.

[Wadester]

I've got my own oxygen and acetylene bottles - when you take them in, you have to wait for them to be filled (was next day IIRC). If you take a swap, then it is hard to tell who owns what.

I inherited the O2 bottle from my dad, and got the acetylene as military surplus. Both had to be hydro'd when I took possession.

[FixerDave]

Originally Posted by JAFO

...

I have a shed out back behind my house- It's not airtight, but sturdy enough.

I know at least this:
-bottles need to be stored securely, ideally upright. If they can't be upright, they need to be placed upright for a day before use.

Always take the regs off and ensure the valves are closed when finished.

Keep a cylinder cap on them when not in use

NEVER use grease or any hydrocarbon to "lube the threads", particularly on O2 tanks.... pretty much asking for a flashover there.

never drop the tanks, for numerous reasons: concern of sheering off the valve, and in the case of acetylene there's a chance of the bottle going endothermic and blowing up.

Anything else?

Yeah... secured upright with fireproof material, aka metal band or chain.

My take... not saying it's right or anything... just me. Cylinder caps are for transporting. I don't take the regs off when not in use. When finished, I do make sure the bottle valves are closed and the torch valves OPEN such that if anything is leaking it will keep leaking and not build up pressure in something that can't take it. Also, I'd be nervous about storing any explosive gas (inc oxygen) in an airtight enclosure. Ventilation is good.

There's a picture floating around of some guy's SUV... leaking propane tank in the back. After he noticed, he drove it out of the garage and decided it would vent faster if he opened the windows... electric windows. He lived, the interior was fine, but all the panels blew off both sides of the shell. Stupid thing looked like it was skinned. Enclosed space is what gets you. A ventilated shed sounds good.

David...

[JAFO]

Yeah I saw tha same thing- a yellow FJ with "TNKA TY" custom plates. At least it was only a modern FJ, thus not a big deal.

Just as a minor point- O2 isn't explosive. O2 is an oxidizer- it promotes combustion but does not itself burn. A pedantic point perhaps, until you see some dumbass use O2 to cool off after a hot day in the shop... and then pretty much explode into flame. Self-emolation by way of stupidity. So yeah, WON'T be doing that!

Also- and not trying to start something here- but you may wish to re-think your storage protocol. The caps are there to protect the valves... both from being knocked off in event of a drop, and to prevent them being bumped and made to leak.

NOT trying to be a safety-mommy sort, (but honestly that wouldn't be bad with acetylene- I understand it's one of the most dangerous gasses to work with in terms of it's explosive percentage (2.5%-80% mix with air). Just... be careful out there, huh? Building shit is all kinds of cool, but the tools and processes we use can bite you if you're not careful..

(this said, I'm the dumbass that was welding up the frame for a welding cart the other night.... looked up after I made the base and remembered I had a bike full of gas and 15 gallons of "loose" gas in cans, 5 feet from the job. This makes me a bit more cautious now... :) )

[fxstbiluigi]

Originally Posted by JAFO

Yeah I saw tha same thing- a yellow FJ with "TNKA TY" custom plates. At least it was only a modern FJ, thus not a big deal.

Just as a minor point- O2 isn't explosive. O2 is an oxidizer- it promotes combustion but does not itself burn. A pedantic point perhaps, until you see some dumbass use O2 to cool off after a hot day in the shop... and then pretty much explode into flame. Self-emolation by way of stupidity. So yeah, WON'T be doing that!

Also- and not trying to start something here- but you may wish to re-think your storage protocol. The caps are there to protect the valves... both from being knocked off in event of a drop, and to prevent them being bumped and made to leak.

NOT trying to be a safety-mommy sort, (but honestly that wouldn't be bad with acetylene- I understand it's one of the most dangerous gasses to work with in terms of it's explosive percentage (2.5%-80% mix with air). Just... be careful out there, huh? Building shit is all kinds of cool, but the tools and processes we use can bite you if you're not careful..

(this said, I'm the dumbass that was welding up the frame for a welding cart the other night.... looked up after I made the base and remembered I had a bike full of gas and 15 gallons of "loose" gas in cans, 5 feet from the job. This makes me a bit more cautious now... :) )

Explain to me how oxygen promotes/supports combustion but does not burn.

[Wadester]

Originally Posted by fxstbiluigi

Explain to me how oxygen promotes/supports combustion but does not burn.

Oxygen, or some other oxidizer is necessary for fire - but it doesn't "burn" - that's what the fuel does. Does air burn? Fire is rapid oxidation - rust is slow fire.

[fxstbiluigi]

Originally Posted by Wadester

Oxygen, or some other oxidizer is necessary for fire - but it doesn't "burn" - that's what the fuel does. Does air burn? Fire is rapid oxidation - rust is slow fire.

What does oxy become after it has gone through a fire?

[Poolside]

Originally Posted by fxstbiluigi

What does oxy become after it has gone through a fire?

CO2 mainly, and some CO. All fuel is a hydrocarbon (CxHx) chain of some sort, well except H2 and hydrazine of course. Call it any CH compound that was built with photosynthesis say.

[fxstbiluigi]

Originally Posted by Poolside

CO2 mainly, and some CO. All fuel is a hydrocarbon (CxHx) chain of some sort, well except H2 and hydrazine of course. Call it any CH compound that was built with photosynthesis say.

Why was hydrazine banned as a fuel for dragsters way back when?

[JAFO]

Originally Posted by fxstbiluigi

Explain to me how oxygen promotes/supports combustion but does not burn.

What is this, a test? Crap.. it's like those dreams in highschool- I'm naked and there's a test today that I forgot to study for...

[dmaxmike]

Originally Posted by JAFO

I was given them by a guy who took them as part of a trade. They have current VIP and HYDRO ,not sure if there's any other inspections needed.

A local gas company said they'll take them in tradeout on filled bottles, so long as they're not marked AIRGAS.

Worse come to it, I make some money on steel salvage. But I've been needing a cutting rig, so going to try that first. I already have a torch I was given, just need some gas and maybe a reg and I'm golden. Granted, I was looking at one of those small, portable rigs, but they're $300 and up, and require more fills. I will likely never need to fill these bottles again.

Before that, I need to learn how to use them, though.. .I believe there are minimum and maximum pressures to be concerned about?

Definitely going to run anti-flashbacks on torch and regs as well.

they sound pretty new so they should be able to be filled. i have never heard of taking them in on trade for new bottles when you own your own but maybe its different down south. i am at an advantage since my family does at least $100,000 a month with our local welding supply company. So i don't pay for shit for my home garage.



if you already have a gas rig and are looking for regulators just buy a new set as they will have all the modern safety features such as the flame arrestors already built in. as far as pressures go i run about 10-12psi for my ace and anywhere from 30-50 for my oxy. no need to take the regs off after use. just close the bottle valves and drain the psi from lines and regs by cracking the valves on the torches.

[Wadester]

Originally Posted by fxstbiluigi

Why was hydrazine banned as a fuel for dragsters way back when?

Hmm. Maybe because it is outrageously toxic? Threshold Limit Value (max exposure level) is 0.1 ppm (parts per million) or 0.13 mg/m3.

Also, for high pressure oxygen - everything is a fuel. Specifically metals that are used to contain it. Here's a picture of what happens with a little contamination:







Single frames taken from high speed video of an ASTM G175 Phase 2 promoted ignition test. Each frame was taken after the first frame to exhibit flame corresponding to the following milliseconds time periods from this point: (a) 4 ms, (b) 15 ms, (c) 26 ms and (d) 65 ms.

Oxygen fires like this usually only last a few milliseconds - but pretty much blast everything. They tend to self-quench, but only after going off like a bomb. Imagine your hand on the valve handle there.

Info from here: http://www.astm.org/SNEWS/ND_2008/ch...wton_nd08.html

[JAFO]

So yeah, that's gonna be fun having it stored in my garage...

[Wadester]

Originally Posted by JAFO

So yeah, that's gonna be fun having it stored in my garage...

It's not that bad. Just be sure to keep that 3rd leg of the triangle (heat/ignition) under control. Make sure fittings are clean and dry (no oils!) when connecting. And always open valves slooooooowly to reduce the chance of particle impact ignition. It's not like the old days when you were making acetylene by dropping calcium carbide into water in a big sealed tank (an exothermic reaction that creates a gas that can detonate/explode).

[JAFO]

Honestly, the heat is the biggest concern. This will be in an exterior, unattached garage. In South Cackalacki. 100 degrees in the shade during the summer...

[KTM640Dakar]

Originally Posted by ChrisE

What happened here





Welding Class....Welded an aluminum box using stainless steel rod...

Why? Did you grab the wrong TIG rod? That looks like poop.