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
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!
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- (same fitting as BOC - no bottle rental.
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
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
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
---------------------------------------------------------------------------------------------------------
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.
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.
Any further comments would be appreciated.
John H
-----------------------------------------------------------
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.
formatting link
Charles
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What do they charge for (a) the cylinder, and (b) the gas?
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
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