Bill Edwards
Member
- Messages
- 4,959
- Location
- Scarborough, North Yorkshire
I'm trying to pick my way through the minefield that is getting hold of oxy acet.
I'm still getting prices on half size bottles, but before shelling out what looks like £146 per year for a pair plus costly acetylene refills I'm trying to establish whether a rent free acetylene option could work, leaving me to rent oxy for heating, brazing and cutting using propane and keeping the acetylene for actual welding. I don't like swapping round all the time, but wasting money on gas isn't attractive either.
What I'm struggling with is figuring out how much gas I'll get through. I can work out how many rent free bottles I can go through before it is cheaper to rent, but that information is of limited use when I can't establish what my usage will be. It would be good to work it out rather than waste money with trial and error.
Hobbyweld give specs for their acetylene cylinder as:
Fill - 17.5 bar / 250 psi
Capacity - 0.81 cubic meters
Water Capacity - 5 litre
But the one that I think might be a good rent free option (no Hobbyweld places within 40 miles from me) is the 10l one from Barnet (http://barnet-welding.co.uk/acetylene).
But how much gas is there in the 10l cylinder?
If I take the 5l cylinder as having a capacity of 0.81 cubic meters then Google converts this to 810 liters. So am I right in thinking that a 10l cylinder must be double that therefor containing 1620 liters?
If that is so then according to the gas consumption figures (from http://www.twi-global.com/technical-knowledge/job-knowledge/equipment-for-oxyacetylene-welding-013/) a no. 3 nozzle will use 1.4 liters per minute. On a 10 liter cylinder I think that equates to 1157 minutes (19 hours) of welding. That seems like a long time - heck, I could get over 2 hours of welding 8mm thick steel with a number 25 nozzle!
Have I made an awful mistake in my calculations?
I'm still getting prices on half size bottles, but before shelling out what looks like £146 per year for a pair plus costly acetylene refills I'm trying to establish whether a rent free acetylene option could work, leaving me to rent oxy for heating, brazing and cutting using propane and keeping the acetylene for actual welding. I don't like swapping round all the time, but wasting money on gas isn't attractive either.
What I'm struggling with is figuring out how much gas I'll get through. I can work out how many rent free bottles I can go through before it is cheaper to rent, but that information is of limited use when I can't establish what my usage will be. It would be good to work it out rather than waste money with trial and error.
Hobbyweld give specs for their acetylene cylinder as:
Fill - 17.5 bar / 250 psi
Capacity - 0.81 cubic meters
Water Capacity - 5 litre
But the one that I think might be a good rent free option (no Hobbyweld places within 40 miles from me) is the 10l one from Barnet (http://barnet-welding.co.uk/acetylene).
But how much gas is there in the 10l cylinder?
If I take the 5l cylinder as having a capacity of 0.81 cubic meters then Google converts this to 810 liters. So am I right in thinking that a 10l cylinder must be double that therefor containing 1620 liters?
If that is so then according to the gas consumption figures (from http://www.twi-global.com/technical-knowledge/job-knowledge/equipment-for-oxyacetylene-welding-013/) a no. 3 nozzle will use 1.4 liters per minute. On a 10 liter cylinder I think that equates to 1157 minutes (19 hours) of welding. That seems like a long time - heck, I could get over 2 hours of welding 8mm thick steel with a number 25 nozzle!
Have I made an awful mistake in my calculations?