cheapest acetylene ?

[zardoz]

I promise i did try to look it up here. But after half an hour of scouring threads, I still cant work out which is the cheapest method of obtaining acetylene. There are so many variables. Taking in to account bottle size, Bar pressure, transport charge,(pick up charge!) filling cost and rental cost, etc.

Please help a puzzled fellow forum member.

 

[hotrodder]

Fill pressure ain't gonna vary much with acetylene due to it's properties... can't pressurize it directly to more than 15psi safely so it's dissolved in acetone and the cylinders are stuffed with a porous material to 'soak it up'. Max cylinder pressure is only 17.2bar/250psi IIRC giving less scope for the 1/2 full cylinder thing

There's 2 rent free sources that i'm aware of, Albee (airliquide) and hobbyweld. Southwest gas were talking about it, dunno if it's happened yet. You'll have to find and call your local agent as prices will vary

The biggest variable in working out which is the best value supplier is how much gas you'll get through. Used daily, dragged out once a week/month etc

Very roughly the Albee-flame appear to be about the same size as a BOC flamepak 20. Dunno what the equivilant size from Airproducts is off the top of my head. Find the BOC forum/Volkszone offer threads, phone 'em up and ask for the same deal with a flamepak after reacting appauled at the regular prices. Whether anything will come of it is anyones guess but if you don't ask...
Same thing with Airproducts, a forum member (SBK?) got some sort of deal for the forum and there's a name and number somewhere, just search the gas subforum for 'airproducts'. Again, it's for shielding gas but if you don't ask...

Rental, for BOC at least, is done on cylinder size not contents i.e. flamepak 20 is same rental/cylinder as X sized shielding gases currently £71.65 +vat per cylinder/year. Flamepak 50 = Y sized O2. Pick up/delivery prices are done per transaction

From random internet prices and the June 2013 BOC pricelist...
Albee acetylene refills are only ~ £5 more than BOC flamepak 20 but the O2 refill is virtually double the price
Hobbyweld acetylene is half the size and a tenner more, O2 similar price to albee but only 137 bar i believe which'd make it ~ 3 - 4 times the price of BOC until you factor rental into the equation which heavily influences the total price per year

Any of those three could be the cheapest or the most expensive depending how much you use as albee is high start up price but no rental while hobby weld is high gas prices (higher than it appears due to small volumes) with a returnable deposit i.e. cheapest if you rarely use it but gets to be the most expensive if you use a lot

 

[Mr shiney]

I worked out that it was cheaper to rent a BOC flame pack 50 and pay he rental than the cost of getting the sampler sizes and keep swapping them. I get 6-12 months out of a 50.

I thine try to time it so I change the Argon, O2 and Acetylene at the same time so I only have one collection fee.

 

[AndyStobbs]

Speak to Co2 services in Connors Quay. I get all my gasses from them - rent free. Haven't had to change the Acetylene yet so can't quote you any figures. They deal with Air products and Air liquide so if you had an empty you may well be able to save the deposit.
Just got my Argon from them, its an Air Liquide cylinder, almost six foot tall (insert size letter here) 200Bar fill. Deposit was £120inc VAT and gas was £72inc VAT.

 

[CRS51]

As above, I get my gas from CO2 services as well they are very helpful. Last time we had a full size acetylene it was getting expensive but cannot remember the exact price.
Chris.

 

[zardoz]

WOW. I really wasnt just being dim, it is extremely confusing. I suppose as Hottrodder says, it depends 'how much you use'

I will take all your advice on board. A big thanks to everyone who replied.

ps: i forgot about acetylene being disolved in porous stuff. I remember being told once it was cement! Anyone know if thats true ?

 

[lshigham]

WOW. I really wasnt just being dim, it is extremely confusing. I suppose as Hottrodder says, it depends 'how much you use'

I will take all your advice on board. A big thanks to everyone who replied.

ps: i forgot about acetylene being disolved in porous stuff. I remember being told once it was cement! Anyone know if thats true ?

It's called Agamassen, used to be a mixture of coal, cement and asbestos but I can't find what is used now. It's not actually dissolved in it but in Acetone or DMF which is soaked up by the Agamassen.

 

[AndyStobbs]

I thought it was Capock now - not sure how its spelt but phonetically I was taught to pronounce it as Kay-Pock.

 

[Jim Davey]

It is kapok, again not sure if my spelling is any better than yours but that's definitely what they put in the Acetylenes these days.

 

[Jim Davey]

WOW. I really wasnt just being dim, it is extremely confusing. I suppose as Hottrodder says, it depends 'how much you use'

I will take all your advice on board. A big thanks to everyone who replied.

ps: i forgot about acetylene being disolved in porous stuff. I remember being told once it was cement! Anyone know if thats true ?

How much do you get through then? Our sums worked it that even if you got through 3 Albees in a year you were still saving money over an average rental account customer. (Once you get past the original purchase price of the bottle that is)

 

[hotrodder]

Spelling is kapok, it's a natural fibre and one of several different materials/mixtures of materials used over the years to create a 'porous monolithic mass' in the cylinder that looks something like this (no i didn't gas axe a cylinder in half! pic stolen from google)

Another potential plus point for Albee i forgot about is that the cylinders are their integra type i.e. they supply and service the regulators. Mute point for anyone that's just bought a shiney new kit that includes regs and probably a negative point for anyone that's sprung for dual stage regs (MUCH nicer but ££) as i'm guessing they're single stage affairs?

 

[Jim Davey]

They are single stage as far as I'm aware.

 

[hotrodder]

Cheers Jim. Pretty grim title but talks about the different materials used over the years... http://europepmc.org/articles/PMC1007946/pdf/brjindmed00141-0071.pdf
More modern... http://www.asiaiga.org/docs/2010_meeting/Safety%20Features%20of%20acetylene%20cylinders%20and%20bundles_Ernest%20Khoo_web%20version.pdf

 

[zardoz]

Thats an interesting read, Hotrodder. Cheers!

(As i took my asbestos awareness safety certificate, not long back. I actually knew what Crocidolite and Chrysotile asbestos was. Seems like more workers at acetylene plants died of asbestos related diseases, than ever died of gas explosions! )

 

[Agautosport]

Southwest Gas Supplies have been trialling Propylene as a replacement for Acetylene with good results.
We have 10 litre and 20 litre cylinders available branded as "profuel" .
As propylene is an LPG all you get in one of our cylinders is fuel , no acetone or solid mass , therefore we believe our cylinders will out last comparable Acetylene cylinders many times over.

Alan

 

[backpurge]

Alan, how do you find it for welding

 

[Agautosport]

Alan, how do you find it for welding

Hi, certainly seems ok from the feedback we are getting , you have to increase the nozzle size and reduce the pressure compared to Acetylene .
We have a stock of specific nozzles to help make welding and brazing easier with profuel.

Alan

 

[backpurge]

That is an interesting alternative for people not wanting to use DA

 

[hotrodder]

Does propylene not suffer the same oxidised weld thing that applies to the other acetylene alternatives? I've read conflicting stuff about it with some saying no good for welding and others saying it's OK but most of it was forum comments or those with a vested interest i.e. selling it.

AIUI mixture wise it's a little worse than MAPP with regards to O2 consumption so unlike acetylene it's not taking O2 for the secondary flame from the surrounding air resulting in a 'proper' CO2 shield around the weldpool? I've welded with MAPP (Ok, generic replacements for it) and while it kinda worked on thin sheet it was like trying to use O/A with a slightly oxidising flame

Propylene appears to produce slightly more heat than MAPP from it's primary flame but it also produces more in it's secondary. A lot more, closer to propane than it is to acetylene in that regard

Figures from TWI...

 

[Agautosport]

Does propylene not suffer the same oxidised weld thing that applies to the other acetylene alternatives? I've read conflicting stuff about it with some saying no good for welding and others saying it's OK but most of it was forum comments or those with a vested interest i.e. selling it.

AIUI mixture wise it's a little worse than MAPP with regards to O2 consumption so unlike acetylene it's not taking O2 for the secondary flame from the surrounding air resulting in a 'proper' CO2 shield around the weldpool? I've welded with MAPP (Ok, generic replacements for it) and while it kinda worked on thin sheet it was like trying to use O/A with a slightly oxidising flame

Propylene appears to produce slightly more heat than MAPP from it's primary flame but it also produces more in it's secondary. A lot more, closer to propane than it is to acetylene in that regard

Figures from TWI...


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I guess what the job you are welding comes into the equation .
Most of our products go into garages where Oxyacetylene is manly used for heating , cutting and the occasional bit of welding such as a bracket on an exhaust or similar.
In these instances our Propylene works fine.
If you are doing more technical work you would have to satisfy yourself as to the suitability of the product.

Alan
Southwest Gas Supplies Ltd