gas advice

[christofloffer]

hi chaps,
i am retraining as a welder at the moment. i have a mig and a stick welder and i am slowly but surely building up my kit. one thing i have got on my wishlist is better cutting equipment. at present i am using a grinder and its not really best for the situation. for one its very loud. so i looked at a plasma cutter and they are pretty expensive and fairly limited. plus i would rather fork out a bit more when it comes to getting a TIG welder and get one that will do cutting too.
so i figure oxy/fuel is the best option as it then gives me the option of brazing and heating. plus if in future i have a call for acetylene i can get some and i already have the kit. i know it leaves more distortion but for what i am doing it would be fine. at least it would vastly reduce time with the grinder.
the only thing i am unsure on is how much gas i would be getting through. as it seems fairly expensive i want to get an idea of how much i should look at. it would be infrequent use, probably just over hobby use.
so any advice on what size of bottle i should be looking at or how long they last?

thanks in advance, i know its a bit of a vague question i just want to get as much info as possible.

 

[shenion]

I have a cheap O/A torch. i set it up with propane so i can use my BBQ tank.

Works well for heating and brazing. I did some cutting with it and quickly realized I would want a bigger oxygen bottle. Mine is just a real small one, maybe 16" tall. I plan on getting a bigger oxy bottle.

I have a small acetylene bottle. I have never had it filled as I don't want to worry about safety issues. If I ever need it. I'll have it filled..

 

[Bill Edwards]

You'll need at least 3x as much oxygen as fuel for cutting. You can rent bottles at high cost, or pay a deposit where it doesn't cost you to keep them long term, but you pay through the nose for refills.
Depending on usage and how much time you have to faff around you could use oxy propane for cutting and heating as propane is dirt cheap. It's not as nice to use though, but adequate for cutting. It'll also use a bit more oxygen. Then have a bottle of acetylene for welding, if it only does that it'll last a while. It may be cheaper to pay a deposit on the acetylene and either do the same for oxygen, or rent one if you'll be using a lot.

As to actually calculating exactly how much you'll use, I've already done this - have a read:

http://www.mig-welding.co.uk/forum/...ents-how-long-will-it-last.46421/#post-515964

 

[christofloffer]

thanks guys, thats a big help. i am going for propane as fuel as i mainly need cutting, heating and brazing. so small bottle of gas and big bottle of oxygen is going to be the way forward.
i'll be going rent free i think, its probably cheapest for the time being.

 

[Bill Edwards]

Bear in mind that you can't weld with it - don't even bother trying as the chemistry is wrong!

 

[BrokenBiker]

top tip for oxy propane. if you are just wanting to heat something like bar stock to cherry and aren't worried about it taking a few minutes, don't run the oxy. if you need quick local heat, use the oxy. I tend not to use the oxy for anything except cutting, and when I need a lot of direct heat on a small area without heating the rest of the material up. saves a lot of oxy that way

 

[christofloffer]

just to extend this a little rather than a whole new thread.
are those carbon arc brazing/gouging attachments worthwhile to use for infrequent heating, bending etc?
they seem like a good, if antiquated, idea. i would only really need one for applying heat when bending bits or removing knackered bolts. possibly the occasional hot rivet. just thinking it may be cheaper than the gas or a blowtorch which takes forever to do anything.

also on the original topic, i have decided against gas cutting. maybe when i have a proper workshop and i am earning i can warrant it but its out of reach for now. i would be better off putting the money in for gas for the mig and get into that properly, then i can drop the gasless stuff. i looked around and asked various people and a plasma cutter would be a better long term investment.

 

[zzr1200]

Carbon arc is a waste of time and money in my opinion, I had one 40+ years ago used it to braze my first set of sills on my old car at the time, cost a fortune in rods and overhead brazing wasn't fun.

Find yourself a small propane cylinder and rent free oxygen cylinder if you want to heat metal, possibly look out for a cheap forge or build one...