TIG SS, argon/co2 possible?

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JetSet
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TIG SS, argon/co2 possible?

Post by JetSet » Wed Jun 14, 2006 11:27 pm

Hi.

I ordered a few disposable bottles (renting large bottles not viable, and only have a couple of months a year in which I can weld), asked for pure argon but received an 86%/14% argon/co2 mix instead. I cant really be bothered with the hastle of packaging/posting 3 bottles (time & nothing left in the budget!). Will it suffice?

I am just starting out with TIG, will be welding 0.9mm 304. If I do use argon/co2, what differences would I notice when getting hold of pure argon next time?

Thanks.
JS.

Al Belli
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re: TIG SS, argon/co2 possible?

Post by Al Belli » Wed Jun 14, 2006 11:59 pm

Hi JetSet,

When You go to pure argon, the arc is much easier to start and maintain because argon has the lowest ionisation potential ( voltage ) of any of the shielding gasses. When welding thin materials with low thermal conductivity (like stainless steel), the arc will inpart less heat to the material and will help to prevent warpage and burn through.
I also recommend that You use ceriated tungsten electrodes for best starting and control of the arc. Ceriated is substantially better than thoriated, and is not radioactive. ( don't breathe the grinding dust from thoriated tungsten unless You are already inhaling two packs of cigarettes and don't care about lung cancer ) !!!!!!!!!!!!!!!!!!!!

" Hazards-
Thorium (Th) is slightly radioactive with a long half life and emits mainly alpha () particles, but occasionally some beta () and gamma () radiation is emitted. Alpha particles cannot penetrate skin or even paper. However, they are harmful if released inside the digestive tract, or inside the lungs, where they act as a carcinogen.
Thorium oxide is, therefore, a low level radioactive material which may give rise to both a small external radiation hazard and an internal hazard from ingestion or inhalation. The external hazard estimated for a welder holding an electrode for a whole year is a very small fraction of the maximum permissible radiation dose and it is concluded that the external radiation hazard is likely to be negligible.

There is almost no release of radioactive material during arcing. However, to achieve maximum arc stability the electrode tip is ground to a conical point before use. This shape is maintained during use by regular regrinding. During the grinding process, particles of tungsten may be produced with thoria on the surface. It is these dust particles that create the major hazard, as they may be inhaled, and the thoria may release alpha particles from the surface.

In a review of air sampling measurements carried out during grinding it was concluded that during grinding air concentrations could approach or even exceed concentrations at which it would be necessary to consider designating the area as a controlled area as defined by the Ionising Radiation Regulations 1999"
"Preparation/Grinding
Grinding creates the greatest hazard as the exposed tungsten/thoria area is greatly increased and fine particles of potentially radioactive dust are released into the atmosphere.
It is recommended that a dedicated grindstone with local dust extraction is used, and a simple filter mask is worn unless the number of electrodes used is very small (less than about 20 per year). If the grinding wheel is not fitted with a protective viewing screen, eye protection should be worn. The air extract from the grindstone should be arranged so that the particles are deposited into a substantial disposable bag.

A safe method of collecting and handling the dust from the collection unit must be used to minimise release to the atmosphere (for example, it could be placed in a sealed paper/plastic bag.)

The area round the grinding wheels should be cleaned daily with a vacuum cleaner to remove dust particles. If a high efficiency vacuum cleaner is not available, then the material should be damped down to minimise dust.

Workers should be encouraged to wash their hands before using the toilet facilities, and before taking work breaks, and for this reason the washing facilities should be close to the work areas "



Al Belli

Dang911
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re: TIG SS, argon/co2 possible?

Post by Dang911 » Thu Jun 15, 2006 1:53 am

ummm..... Does that mean its bad to hold 3 electrodes in your mouth, while you file the fourth, and then keep switching them?

Very nice information to know, thanks.....
Louder is ALWAYS Better!!!

JetSet
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re: TIG SS, argon/co2 possible?

Post by JetSet » Thu Jun 15, 2006 2:09 am

Cool, thanks. Nice to know :-)

My set came with a couple of thoriated electrodes (red tips) I think I will replace them tomorrow (to orange tipped i believe).

Thanks.
JS.

Al Belli
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re: TIG SS, argon/co2 possible?

Post by Al Belli » Thu Jun 15, 2006 12:31 pm

Hi,

This is an excellent source for tungsten welding electrodes :

http://www.aglevtech.com/63.html

Al Belli

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re: TIG SS, argon/co2 possible?

Post by El-Kablooey » Fri Jun 16, 2006 12:38 am

You can't just buy a refillable argon bottle in the UK? Here in the states (this area at least) everyone owns their own bottles. When the bottle runs dry you go trade it for a full one, just like swapping 20lb propane tanks. I bought a pretty large tank, it's about 5' tall and 9-10" in diameter. I got it used from a guy who was quitting the trailer building business. The tank was completely full already and I only paid $60. That much gas will probably last me a year between fills.

JetSet
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re: TIG SS, argon/co2 possible?

Post by JetSet » Fri Jun 16, 2006 10:09 am

Not that I am aware of. The general thing to do here it seems is to open an account with BOC gas and rent a bottle, thats what my local welding store suggested anyway. The problem is cost; £100 setup, £10 delivery, £30 a year rental, £40 refill (figures off the top of the guys head, not accurate). I only get 2.5 months of welding a year so it just isnt worth it.

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re: TIG SS, argon/co2 possible?

Post by Jim Berquist » Wed Sep 13, 2006 1:34 am

Argon prices:

Where I work we use Argon to do a HV test to check the insulation on wire spools we construct. Glows a really cool blue color if there is a fault.

We pay $43.00 a tank and order 14 at a time , every 2 months. Our tank rental is $40.00 a year.

May be Worth just purchasing a tank and having it filled. No Rent. It's yours. When it runs down. Have it filled and pick it up??? That way you know the status of the tank, Not a exchange! and with a good valve it should last you a few year???

Just a thought!!
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pezman
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re: TIG SS, argon/co2 possible?

Post by pezman » Wed Sep 13, 2006 2:27 am

Dive shops in the US sell argon in small "pony bottles" for use with dry-suits. Maybe the same situation holds in the UK?

Jim Berquist
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re: TIG SS, argon/co2 possible?

Post by Jim Berquist » Thu Sep 14, 2006 1:19 am

There you go! There has to be other options! What about the little bottles used for Ox Acetylene set ups. 20 liter or what? As fare as I know Argon can be charged into a Ox bottle set up. Labeled as such....As fare as I know, the only special bottles would be Acetylene as they have a Reson filler to stabilize the gas. .

Jim
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