oxy propane

[BrokenBiker]

what are the 'average' sized bottle of oxy and propane people are using in a hobby/home workshop and how long do they last for general pinpoint heating with say a welding tip to get nice clean tight bends in say 30x3mm flat bar of a bit of 12mm round bar?

 

[hotponyshoes]

If that's the biggest section you will be heating I'd look at induction.
Probably cheaper to get the kit (unless you already have the gas stuff) and certainly easier / cleaner / cheaper to run.
Possibly safer as well.

For oxygen the 'choice' (and the cost) will probably be whatever is available locally.ci currently have the hobbyweld rent-free.
Mainly because that's all that's available within an hours drive.
The rent-free suits me as I don't use it much.
Basically, if you use less than 2-3 bottles a year, rent-free works out cheaper.

For the fuel I have refillable gas cylinders so just fill them up at the lpg pump.
If you buy calor/flowgas/whatever propane cylinders it works out far cheaper per kg in the 48kg bottles.

Another cheap option for the size you are bending is just use propane alone.
Heating times are longer but, if it's a repetitive job, make up a jig that holds the torch and you drop the piece in. Contain the heat with fire bricks.
Once the first piece is hot you can heat the next while working the first.

 

[BrokenBiker]

If that's the biggest section you will be heating I'd look at induction.
Probably cheaper to get the kit (unless you already have the gas stuff) and certainly easier / cleaner / cheaper to run.
Possibly safer as well.

For oxygen the 'choice' (and the cost) will probably be whatever is available locally.ci currently have the hobbyweld rent-free.
Mainly because that's all that's available within an hours drive.
The rent-free suits me as I don't use it much.
Basically, if you use less than 2-3 bottles a year, rent-free works out cheaper.

For the fuel I have refillable gas cylinders so just fill them up at the lpg pump.
If you buy calor/flowgas/whatever propane cylinders it works out far cheaper per kg in the 48kg bottles.

Another cheap option for the size you are bending is just use propane alone.
Heating times are longer but, if it's a repetitive job, make up a jig that holds the torch and you drop the piece in. Contain the heat with fire bricks.
Once the first piece is hot you can heat the next while working the first.

i have an induction heater, albeit a small hand held 1000w one, but im not really finding its working all that well. its ok on the flat bar, ive made a coil that fits well with the proper gaps required, but the 12mm rod needs to be at bending heat to roll a meter length around a 55mm form to form rings and the induction doesnt heat up a large enough area, if i get 1 bit red then move the heater, the previosu bit cools before ive got the rest hot.

i value time and ease more than an initial cost or an added cost per job. its all a hobby for me so if i can do a job in 15 mins after work rather than 2 hours on a saturday i see that as a major benefit, plus i could see a decent heating set up ebing handy for the cars/bikes and the odd bit of heat treating.

 

[hotponyshoes]

It's certainly handy to have gas about.
I've got a big induction but still kept the gas and use it occasionally. If it wasn't for the local boc depot closing I'd probably still be happy paying cylinder rent for the odd times I use it.

On cars etc it's quicker to blow the flame round a bit of bent metal to get into an area than it is to make up a custom coil for the induction.

There is a bit of a gap in the induction market as well, seems to jump from small hand-held ones without much power up to big hard-wired machines that can't be moved around.

Gas is easy to drag out to the middle of the yard or bung in a truck and take out to the middle of a field.

I've got the hobbyweld ultra oxy, that comes with a quick connector. It's a decent size cylinder that I can lift into a van easily enough.
Fit quick-connects to the propane as well and you could have a 48kg in the workshop and a 6kg for the jobs when you want to go out & about. I use the same one that's on the acetylene so it's easy to swap over.

My only concern with the hobbyweld is if the connector would allow enough flow for the bigger jobs but I've chopped some holes out of 1" before and it's coped with that fine.

 

[Pond frog]

For what you want 19kg propane should be enough 48kg may be cheaper in the long run but they are an awkward lump to move around, ok if you’re going to have it delivered but a pain to pick up yourself.
I use sgs gas for my oxygen as they have loads of stockists near me , 20 or 30 litre bottle should do

 

[Pond frog]

I've got a big induction

What induction heater do you have ? I know very little about them but I can see they are the future for heating metal and I would definitely have use for one

 

[hotponyshoes]

What induction heater do you have ? I know very little about them but I can see they are the future for heating metal and I would definitely have use for one

Just the generic 15kw things,


Got a farriers group buy so £650 each if you can collect from Somerset!

But, some issues,
First thing is, they are single-phase and you'll need to wire it up to an 80a breaker if you want to run it at full power.
15kw is currently the biggest one that will run from a 1ph supply.
3-phase versions are available in higher outputs (or lower draw) so go for one of those if you have 3ph available.

Secondly, they need water-cooling.
Both for the internal components of the machine and the coils.
There are heat-exchangers fitted (so no fin heatsinks) so the water-cooling needs to be running at all times even if you are only heating up 6mm bar.
The upside of this is you get 100% duty cycle. Even at full output providing your cooler can cope.

A few of the guys that have them haven't bothered with an actual cooler, they just feed them from a tap when in use. One of the guys put a meter on his and worked out the tap water was costing him about 70p an hour. I expect the electic cost of running the cooler will be more than that?

 

[BrokenBiker]

For what you want 19kg propane should be enough 48kg may be cheaper in the long run but they are an awkward lump to move around, ok if you’re going to have it delivered but a pain to pick up yourself.
I use sgs gas for my oxygen as they have loads of stockists near me , 20 or 30 litre bottle should do

i can get 19kg propane from a local garden centre and my rent free argon supplier does 20L oxy bottles...looking at the equipoment needed it looks like i can get a full set up for maybe 250 plus gas which is honestly cheaper than i expected...thats for hoses, regs, flash backs, cutting torch, few nozzles and a spark igniter...

i like having handy things that dont necessarily get used all that often, but are there ready. fast local heating has been something ive needed quite a few times over the years but never had the kit. think ill put a saturday shift in, that will pay for pretty much all of it and when i go to fill my argon up next ill grab some oxy as well.

 

[Turbo]

For heating up bar a rosebud tip is a lot better than a cutting or welding tip.
They are designed just for heating and are designated 1h, 2h, 3h, etc the higher the number the hotter they go.
I have a 3h tip and it will get a 16mm bar red hot in seconds. But it is a fearsome thing, quite noisy and it eats gas. And you will still have the problem of getting a long bit of bar evenly heated.
For your sort of work I should think a small propane furnace would be better. You would get the heat soak required to get all your bending done in one hit.

Sometimes I mess around with horse shoe art. I used to use the rosebud to heat them and it was a pain in the butt. Last time i made up a temporary furnace using fire brick and a propane torch. It was a revelation, the shoe got heat soaked, giving me a lot more working time to shape the shoe.

 

[jo1010]

+1 for the flexibility of gas ......it seems s/hand oxy ace gear is cheap these days and it gives a range of heating options ....welding tips for heating small delicate items and a gas axe cutting torch for rapid heating of big thick metal (and can also be used for rough cutting if needed - but these days I tend to use plasma for neater cuts).....oxy propane is almost as fast as oxy ace - and propane is fairly cheap these days.......I use 47kg here anyway for a domestic cooker as house is not on mains gas and full size oxy - the footprint is fairly large though but it's all low maintenance kit....not having to mollycoddle delicate tech in our wet and damp UK climate I see as a big plus