Page 4 of 20 FirstFirst 12345678914 ... LastLast
Results 46 to 60 of 289
  1. #46
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Quote Originally Posted by Ed.. View Post
    I rang Speedgas the other day enquiring about their E size gas cylinders (4.0 cubic mts) and that cylinder to buy was $496 ( D size to buy is $376 and 1.7 cubic mts) and I don't think it included the first fill, the E size fill of 93%Ar 5% CO2 and 2%O2 was $184 delivered. BOC was charging $198 rental per year and about $104 for a refill. So with speedgas you are paying the equivalent of 2.5 years rental up front and then you are almost paying double for the gas refill than what BOC charges forever. Probably after 4-5 years you may get slightly ahead by owning your bottle, also I live near Caboolture and they deliver about every 3-4 weeks to my area, so I wouldn't want to run out in the middle of a job! Looks like I am going to stay with yearly rental as I live within 15 minutes of a BOC dealer. Supagas rental is the same but they charge about $141 for the gas delivered. If you don't use much gas and take several years to empty an E or D size then Speedgas may work out better as you don't pay yearly rental anymore.

    I have almost emptied my bottle so I think I will switch from Supagas and back to BOC.

    Cheers

    Ed.
    the cylinders from speed gas come filled
    https://www.nationalwelding.com.au/gas-c-460

  2. #47
    Join Date
    Mar 2013
    Location
    Ningi Qld Australia
    Posts
    64

    Default

    Thanks for that link, those prices are different from the ones I got from the Speedgas Qld branch and these are from National. I think that they apply only in NSW cause it's quoting me $289 delivery.

    Cheers

    Ed.

  3. #48
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    I'm getting a bit confused when trying to compare the economics of my 6.8Kg beer gas cylinder to the alternatives. For example, the first time I got it filled, it was completely out of CO2 and the homebrew shop guy wrote Tare: 13.55Kg on it before he filled it. I assume he added about 6.8Kg of CO2, so it would have weighed a bit over 20Kg when full. WelderMick pointed out in the previous page that this corresponded to 3,462 litres at standard temp and pressure.

    So what letter size does this correspond to? Looking at that Speedgas site, their D size weighs 17.4 empty and 20Kg full, so 2.6Kg of gas which they say is 1,700 litres. Their E size goes from 32.2 to 41.6Kg, so 9.4Kg of gas or 4,000 litres of gas. Note that neither of the weight vs. litres match WelderMick's calculation, despite argon being a similar molecular weight to CO2.

  4. #49
    Join Date
    Aug 2009
    Location
    Quindanning, WA
    Posts
    175

    Default

    I've seen the same numbers mentioned... 3463L for 6.8kg CO2 (at 0 degrees celcius and 1 atm) and 4000L for E size argon (at 1 atm and an unspecified temperature). I pay $30 for a CO2 fill vs around a $100 the last time i got argon so the economics seem pretty clear.

  5. #50
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by RustyArc View Post
    I'm getting a bit confused when trying to compare the economics of my 6.8Kg beer gas cylinder to the alternatives. For example, the first time I got it filled, it was completely out of CO2 and the homebrew shop guy wrote Tare: 13.55Kg on it before he filled it. I assume he added about 6.8Kg of CO2, so it would have weighed a bit over 20Kg when full. WelderMick pointed out in the previous page that this corresponded to 3,462 litres at standard temp and pressure.

    So what letter size does this correspond to? Looking at that Speedgas site, their D size weighs 17.4 empty and 20Kg full, so 2.6Kg of gas which they say is 1,700 litres. Their E size goes from 32.2 to 41.6Kg, so 9.4Kg of gas or 4,000 litres of gas. Note that neither of the weight vs. litres match WelderMick's calculation, despite argon being a similar molecular weight to CO2.
    Are they all filled to the same pressure?
    Oops... Stupid question on my part there. Yeah I get 1458 and 5271 litres (argon) in theory based on your figures above for the D and E bottles. CO2 is about 10% denser (so less volume for a given weight). The difference between STP and room temperature pressure is minimal, I think (something like 1%??).

  6. #51
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    Just dropped past the local Gasweld who are flogging the Speedgas Swap'n'Go cylinders. It seems they also do CO2 "for welders over 250 amps". The D size CO2 cylinder is specced as 6Kg, whereas the Argon and MIG gas D cylinders are specced as 1.7m3. So why they use weight for CO2 and volume for the other gasses is a mystery. From memory, the volume was claimed at 15 degrees and 100kPa (i.e.one atmosphere).

    D-size CO2 is $319 then $49 to swap, the latter is cheaper than the $70 or so the homebrew shop charge to refill my 6Kg. That said, my cylinder cost $220, so the $100 difference would take 5 refills to make up.

    MIG gas D size is $339 but costs $99 to swap (same price for Argon).

  7. #52
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Good info there Rusty.
    CO2 will be liquid within the cylinder (just like LPG), so doesn't doesn't follow a constant pressure vs volume relationship. I guess also the fact that it is more of an 'average consumer' type of gas might mean that people understand weight better than expanded volume. I don't know, just thinking aloud.

  8. #53
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    I think the penny has kind of dropped for me on the difference between CO2 and MIG/Argon gasses. CO2 enters its most "compact" liquid phase well within the pressure rating of the cylinder, meaning you can pack 6Kg in there. That's not the story with Argon, or a mix of it, meaning you can only get 2.6Kg or so into the same cylinder, resulting in less than half the amount of useable gas.

    So provided you can live with the aggressive behavior of CO2, it's effectively a quarter of the price of a MIG mix in terms of how many litres of gas blow through the torch.

  9. #54
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by RustyArc View Post
    I think the penny has kind of dropped for me on the difference between CO2 and MIG/Argon gasses. CO2 enters its most "compact" liquid phase well within the pressure rating of the cylinder, meaning you can pack 6Kg in there. That's not the story with Argon, or a mix of it, meaning you can only get 2.6Kg or so into the same cylinder, resulting in less than half the amount of useable gas.

    So provided you can live with the aggressive behavior of CO2, it's effectively a quarter of the price of a MIG mix in terms of how many litres of gas blow through the torch.
    Yeah that's it. Still doesn't explain the Kg vs. m3 thing, but there's no doubt CO2 is way cheaper. Even comparing something like 100 argon vs. 93%/5/2, the mix seems quite a bit cheaper.
    So I guess you're sticking with CO2? Which cylinder/reg combo do you use? I'm using argoshield at the moment but considering the swap.

  10. #55
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    Quote Originally Posted by WelderMick View Post
    So I guess you're sticking with CO2? Which cylinder/reg combo do you use? I'm using argoshield at the moment but considering the swap.
    I like the idea of the nicer-looking bead profile you get with MIG gas, and the ability to work on thin sheet a bit easier, but the fact is most of the work I do is farm related using Duragal, and CO2 works really well, and with a bit of technique I can improve the appearance of the profile of the bead.

    I got a 6KG Keg King cylinder of Ebay for $220 delivered (full of gas) and found a CO2 regulator/flow meter at Gasweld - I think it was about $80.

  11. #56
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by RustyArc View Post
    I like the idea of the nicer-looking bead profile you get with MIG gas, and the ability to work on thin sheet a bit easier, but the fact is most of the work I do is farm related using Duragal, and CO2 works really well, and with a bit of technique I can improve the appearance of the profile of the bead.

    I got a 6KG Keg King cylinder of Ebay for $220 delivered (full of gas) and found a CO2 regulator/flow meter at Gasweld - I think it was about $80.
    Have you got any info on cylinder life? are their any inspection/maintenance requirements for refills? One big plus with rental is that those aspects aren't my problem. I'm stuck with rental here in Ballina for my argon, which suits me because I use my TIG all the time, but I've found my MIG usage is much more sporadic - I'll use it flat out for a week, then not at all for a month or two (but I've got quarter of a tank left, so don't want to return the cylinder) - much better suited to having my own cylinder in that situation I feel.

    Much of my mig is on gal 1.6mm RHS and 0.8 wire - how does this go with straight CO2?

  12. #57
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    Quote Originally Posted by WelderMick View Post
    Have you got any info on cylinder life? are their any inspection/maintenance requirements for refills?
    I'm going to guess off hand there's a 10 year thing, and that's one advantage of the Supagas swap'n'go setup - you don't have to worry about your bottle going out of date as you get a different one each time.

    Much of my mig is on gal 1.6mm RHS and 0.8 wire - how does this go with straight CO2?
    Same here. It works really well as far as I'm concerned, but I have never welded with a MIG mix so I can't really make a comparison. If I get a moment I'll fire her up and do a demo weld.

  13. #58
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    And seeing as it's a lazy Sunday arvo:
    IMG_0047 Tack.jpgIMG_0048 Butt.jpgIMG_0052 Fillet.jpg

    40 SHS 1.6, 18volts, 6.5m/min

    Bead width is due to me weaving a bit.

  14. #59
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    thanks Rusty, It looks like the main difference is with the bead profile on the fillet. With the 93/5/2 Ar/CO2/O2 I use, the fillet will tend to be concave if anything - but obviously depends on settings too. On my setup I'd be turning up the volts and wirespeed for that fillet to fill and flatten it out a bit. If you did that with the CO2 what would happen? would it be too hot and burn through?

  15. #60
    Join Date
    Jun 2010
    Location
    Canberra
    Posts
    1,322

    Default

    Quote Originally Posted by WelderMick View Post
    thanks Rusty, It looks like the main difference is with the bead profile on the fillet. With the 93/5/2 Ar/CO2/O2 I use, the fillet will tend to be concave if anything - but obviously depends on settings too. On my setup I'd be turning up the volts and wirespeed for that fillet to fill and flatten it out a bit. If you did that with the CO2 what would happen? would it be too hot and burn through?
    That setting is pretty much as hot as I can go without blowing holes while allowing me to weave a bit to flatten out the profile a bit. At 20V 8m/min I have to do a straight, fast run which results in an even more convex bead.

    The same run with stick (when I get it right) produces a concave bead with nicely wetted edges. I think the less attractive bead profile is one of the main drawbacks of CO2.

Page 4 of 20 FirstFirst 12345678914 ... LastLast

Similar Threads

  1. E versus G argon cylinder pricing
    By WelderMick in forum WELDING
    Replies: 7
    Last Post: 1st Jul 2011, 01:19 AM
  2. How much Argon left in cylinder?
    By matt_o in forum WELDING
    Replies: 8
    Last Post: 28th Nov 2007, 06:00 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •