Gas welding

No idea about the MAPP gas - never heard of it. However, as your torch will have individual valves for oxygen and for gas, there's no reason why you can't use it.

But, you can get oxygen and acetylene cylinders of your own, and get them refilled - there's a firm which supplies them, and they advertise in Classic Motorcycle - ah! Found it!

If you want the phone number I will e-mail you with it.

Yes, you can reuse the Hobby Gas oxygen bottle and regulator.

Yes, you can reuse the Sapphire torch, and the hoses (if they fit).

I may be able to point you to a suitable MAPP regulator for about a tenner, depending on which MAPP bottles you intend to use.

Of not, any propane regulator will in practice usually work well enough; but you will want to change them every so often.

Details depend on usage, but for a low hobby use situation that's about every five or ten years. The MAPP can eat away at the insides of a propane regulator, depending on what it's made of, so some care in use - ie, switch off before or unscrew the regulator between uses - is called for.

However, your real problem is most likely to be - where do I get the MAPP gas from? Petrogas stopped making it some time ago, and supplies are hard to get now.

Note that eg the Rothenburger cylinders marked as MAP-GAS are not MAPP, they are propylene, as are most of the other small-scale supplies with mapp-like names as used by plumbers etc.

These are ok for eg high-heat gas-air brazing - but they aren't hot (or low-hydrogen) enough for oxy-gas welding, you will need real MAPP or acetylene for that.

It isn't impossible to get small MAPP cylinders - but it isn't at all easy. Do you have a source in mind?

-- Peter Fairbrother

There are a number of suppliers offering rent-free acetylene "from next month" - and there have been for a couple of years or more.

I don't know of any who do it right now though - but I'd like to.

-- Peter Fairbrother

I know there has been discussion in the past about Oxy/MAPP gas welding but I wonder if anybody with recent experience can help me out.

I can no longer justify the cost of the rent on my BOC Acetylene bottle and want to change to Oxy/MAPP gas. I presume my existing Hobby Gas oxygen bottle and regulator will be OK for Oxy/MAPP. I realise that I will have to change the acetylene regulator.

The question is can I use my Oxy/Acetylene welding torch (BOC Saphire)and hoses with MAPP gas?

Thanks in advance.

John H

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I faced the same dilemma over the BOC rental costs, and went over to Air Liquide. You need to pay a deposit for the cylinders, and the price of the gasses is more than BOC, but being a low volume user, it should yield worthwhile savings over the long term. And Air Liquide do offer acetylene if you would prefer to stay with that instead of MAPP

Should be

Sorry - silly fingers/keyboard - always having trouble with both...

Thanks for the answers and links so far.

The gas I originally looked at is MAP-Plus which is available from Toolstat ion at £10.78 a cylinder. It is a mixture of Propane, Propene and Dimethy l Ether. I don?t know if burns as hot as MAPP which according to Wikipedi a is Methylacetylene-propadiene.

Regarding acetylene,I have looked at the Albee Professional web site and sp oken to their stockists. I?ve been quoted an initial cost for the purchas e of an acetylene bottle in the region of £220.00 plus £70.00 for refil ls. The current annual cost of acetylene rental from BOC is £72.00.

There is one plus point from buying the Albee bottle is that it is owned by the purchaser and presumably would have a resale value.

As an aside, Hobby Gas and Adams Gas are the same people.

Any further comments would be appreciated.

John H

Having posted a reply I re-read Peter's comments about MAPP and MAP-Plus and realised he had already answered some of my questions! It might teach me to read and understand, but I doubt it!

John H

I don't see acetylene on their web site - do they do it?

AWEM

Thanks for the answers and links so far.

The gas I originally looked at is MAP-Plus which is available from Toolstation at £10.78 a cylinder. It is a mixture of Propane, Propene and Dimethyl Ether. I don?t know if burns as hot as MAPP which according to Wikipedia is Methylacetylene-propadiene.

Regarding acetylene,I have looked at the Albee Professional web site and spoken to their stockists. I?ve been quoted an initial cost for the purchase of an acetylene bottle in the region of £220.00 plus £70.00 for refills. The current annual cost of acetylene rental from BOC is £72.00.

There is one plus point from buying the Albee bottle is that it is owned by the purchaser and presumably would have a resale value.

As an aside, Hobby Gas and Adams Gas are the same people.

Any further comments would be appreciated.

John H

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I've just checked my invoice - for both an oxygen and acetylene cylinder, including gas, VAT etc, I paid £334.80. This was in June. I did ring around the various suppliers and did find some price variations.

I wasn't particularly looking at any resale value for the cylinders - I was just getting hacked off at the ever increasing BOC rental costs. I was getting the impression that they didn't really want to be bothered with small volume users.

Try here for acetylene. My Argon comes from these people.

Charles

Any further comments would be appreciated.

John H

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I have no knowledge of acetylene or other flammable gas cylinders, but as diver I owned my own air cylinders and can tell you that no commercial air station would refill them unless they had a current test mark stamped into the shoulder by a registered tester. That testing was expensive and comprised an internal and external visual examination every two years in conjunction with a hydraulic and ultrasonic test every four years.

Diving cylinders have to operate in corrosive salt water, get knocked about on boats, and still be safely filled to 3400 psi so the testing was fairly stringent, but I daresay there will be some sort of lesser controls on what gas cylinders can or cannot be filled, so it is worth investigating any such additional cost that might be involved.

Cliff Coggin.

"Charles P" wrote

Try here for acetylene. My Argon comes from these people.

Charles

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What do they charge for (a) the cylinder, and (b) the gas?

Hi Charles good to that you are still alive and kicking :)

Yes they do acetylene, but in mighty small bottles:(

Andrew

BOC always used to say inspection was needed every ten years

Andrew

Andrew

Yes, still alive and kicking - just working rather hard and not getting enough time making stuff. Still, it could be worse. I trust that you're still buying ever bigger toys to squeeze into that huge shed?

I'd quite like gas welding kit but have never been able to justify the cost of the bottles. I find that TIG is a pretty good substitute for smaller bits but regrinding tungstens is a PITA

Charles

The bottles get used for heating and cutting mainly for my occasional use, but I resist going to propane as it's just not as hot :(

As for tungsten sharpening, I spotted a dedicated sharpener on eBay the other day - looked like a glorified angle grinder with a fitting that took the electrode at the right angle, but I think that you still had to twiddle it. Absolute bargain at £450 :) Little Wrongs with that :)

Andrew

I handed my BOC acetylene back in recently as I used it so little I couldn't justify the imminent rental renewal. I'll use oxy propane instead. It has been years since I did any OA welding as I have other equipment I can weld with so mainly used it for heating, brazing and silver soldering. I doubt my house insurers would like it either what with the paranoia with acetylene. I know a local workshop has a specific exclusion on acetylene, oxygen can be kept inside, and propane has to be stored outside when not in use. I'll see how I get on with the oxy propane and have the opportunity to try an oxygen concentrator and if that is OK then I may return the oxygen bottle when it's empty. I can get a refurbished ex medical oxygen concentrator for £150 so that's about a years BOC rental, gas fill, and surcharge. The oxygen concentrator should handle my needs and I can use/borrow a big bottle if need be. I don't know when BOC barcoded their bottles but my acetylene bottle didn't have one.

Hi Charles too :)

If you have a water-cooled torch, or are using low amps, maybe just use a size smaller electrode and don't bother sharpening it? I haven't tried that ..

BTW, do not of sharpen thoriated electrodes on a bench grinder. Nasty. You probably shouldn't sharpen any tungstens on a bench grinder, but it really matters with thoriated tungstens.

Alpha emitters with a 20+ year biological half-life .. are to be avoided.

I have a 4 lpm concentrator, which runs a small torch quite well - but by itself it isn't enough for larger work.

At the moment I use a wheelie-bin full of balloons as an oxygen store (yes, it works well), but I am working on a small oxygen compressor - not a project for the faint-hearted or unknowing - to fill cylinders to about 1,000 psi. That's low enough that they are most unlikely to break, but high enough for decent mass storage,

-- Peter