MAPP vs MAP//PRO for welding?

Martin H. Eastburn wrote:


We don't *have* Home Depot in the UK. Or anywhere in the EU, afaik.
You can buy argon or argon mix bottles in the UK, and swap them out (if you are near the only place that does it properly, in Kent, which I'm not - carriage fees usually make it uneconomic otherwise, but if you only use a little bit it might be okay - or are lucky enough to have a supplier who caters for small orders, which is unusual but not unheard of. But try getting industrial helium!).
But TIG gas isn't acetylene, and you *can't* do that with acetylene in the UK, it's seriously against the law (for all practical purposes).
Oxygen isn't quite as bad, but it's still not easy.
A local gas supplier also does a free weekend or weekdays-in-a-week loaner of TIG gas, and even oxygen bottles - but this is unusual in the UK, to put it mildly! Won't do it for acetylene though.
There's a whole bunch of newish EU law about gas bottles (actually it's oldish EU law, but the exemptions people have been working under have ended), which the UK takes seriously, and especially about oxy and acetylene bottles.
Been bad for a few years now, especially for small scale suppliers who have almost all gone out of business - the big boys just charge more for the paperwork, and even more than ever for smaller orders (which they never really wanted in the first place).
There are probably some safety benefits involved, but they are swamped by the cost of paperwork ..
.. and also because the Fire Brigades close off the roads next to a fire where there is an acetylene cylinder for 24 hours, which costs Megabux. Even if it's not needed for safety reasons, that's the regulations. More than my job's worth not to comply.
:(
And can anyone answer my original question please!!: can you weld steel with oxy/propylene? Is the inner flame hot enough, is the outer flame too hot? For my purposes, you can just about weld with oxy/MAPP.
Just got a case of propylene (bought as MAPP, but supplier is cool), don't know whether to open it or send it back - and it's burning a hole in my imagination (or something) ...
Thanks,
-- Peter Fairbrother

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Base gasses, such as Methane, Propane, Propylene, Propadiene, methyl-Acetylene, and butane are all LP gasses, as in Liquified Petroleum gasses. They are all derived from Petroleum Production.
These gasses can be made into mixes such as MAPP, Flamal, or Chemtane to name a few. MAPP stands for Methyl-Acetylene Poly Propadiene, and is a gas mix.
Here is a decent comparison of some fuel gasses.
<http://www.bernzomatic.com/bernzomatic/consumer/jhtml/gasTypeComparison s.jhtml>
MAPP is going away in the US because Propadiene is becoming more valuable to the plastics industry than the welding industry. Flamal and Chemtane are newer mix gasses that are replacing MAPP.
Here in Seattle, it is nearly impossible to get a large MAPP cylinder filled.
Propylene is a little hotter than Propane, but not as hot as any of the gas mixes.
None of these gasses are appropriate for gas welding of steel because of he high Hydrogen content of the flame, which gets infused into the weld puddle, rendering the weld very brittle.
Soldering, Brazing, Cutting, heating, bending are all excellent uses for LP fuel gasses.
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Ernie Leimkuhler wrote:

No - it stands for Methyl-Acetylene, Propadiene, Propane.
MAPP gas is, or was, a mixture of these chemicals*, made almost exclusively by Dow Corning, who have now ceased selling MAPP gas - though there is also a similar mix available in Australia, can't remember the name, which afaik is not made by Dow.
* these are proper-ish chemical names btw, all identifying exact substances; unlike "propylene", which is often used to mean many different things unless it's marked UN 1077 - in which case it is then an alternative name for propene, CH3-CH=CH2.

It doesn't include propylene (or propene) though.

:(
That's what I thought - but am not still sure of.
Is oxy/propylene hot enough to weld with? Is the inner flame hot enough, or the outer flame too hot?

As I explained in an earlier post, that isn't significant to me.
Thanks,
-- Peter Fairbrother
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If I were you, I would look into a small inverter TIG welder. Since you have been using gas welding, I think you would find TIG easy. It is very much like gas welding, but the " flame " is hotter.
Ernie is the US expert on welding. If he says you are out of luck on the gas, you probably are.
Dan
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snipped-for-privacy@krl.org wrote:

I have one :)

I have the greatest respect for Ernie's knowledge of welding - but he's not a chemist.
I agree that it's going to be almost impossible to get MAPP gas - but will oxy/propylene weld?
No-one has answered that question. So I did a bit of chemistry math, and it seems unlikely :( - but not impossible, and any reports from practical experience would be good.
Oxy/MAPP gas will weld, it was designed for welding - but oxy/propylene wasn't.
An alternative might be acetylene from carbide. I can get carbide cheaply enough, but only very small low-pressure (~ 1 psi) generators and I'm not dumb enough to try and make my own - acetylene is extremely dangerous!
-- Peter Fairbrother
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Ernie Leimkuhler wrote:

Flamal is propene, aka propylene - but Chemtane and Flamex are just outright cons.
If only there was effectiveness regulation for these wild advertising claims.
-- Peter Fairbrother
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wrote:

Even higher than stick welding with an ordinary rod? Seem to recall that you posted that hydrogen embrittlement with stick only becomes an issue at thickness greater than 1/4 inch. Guessing that exception does not apply here.
--
William

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You did have Home Depot...
But the point was to buy your bottle. Not rent it. Then it is a trade in and buy gas only.
Leasing a bottle normally requires a deposit and a yearly fee. It might be that acetylene is only for business customers only or those with accounts. It might have been removed as being more dangerous and only top tier companies can get them.
I'd talk to your dealer and find out what are the facts. And to provide specs on the gas. And is it equal or better.
Comparison to Acetylene would be important. Temperature and heat.
http://en.wikipedia.org/wiki/Propene C3H6
Search your vendor gas company web pages. Get hasmat as it might contain more than you think.
Martin
Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com /
Peter Fairbrother wrote:

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On Sat, 06 Sep 2008 00:37:28 +0100, Peter Fairbrother wrote:
<snip>

<snip>
Hi Peter
Could you tell me the name of the supplier in Kent please? That's where I am. I don't use much Argoshield per year & I'm fed up of paying 60 odd PA for rental. Prolly used 1/4 bottle this year. I used to be able to buy CO2 from our local welding supply shop (pub gas bottles)
Many thanks
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Balders wrote:

Adams Gas 2 Bath Road Margate Kent CT9 1SJ
0800-1954445 snipped-for-privacy@adamsgas.co.uk http://www.adamsgas.co.uk/Default.aspx
The rent-free welding gas bottles are 1.37 cu m / 1370 l / 48 cu ft. Not huge, but okay for maybe 1-3 hours of occasional work depending on flow, and much better value than disposables.
I don't know whether they do Argoshield as such rent-free - though they do do 5% and 20% CO2/argon mixes in rent-free bottles, 64.66, and you get 40 back on the bottle.
I think they also do CO2 rent-free, but I'm not certain.
People are keeping a close eye on their business model, and it may spread, but not yet afaik.
HTH,
-- Peter Fairbrother
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On Mon, 08 Sep 2008 17:26:31 +0100, Peter Fairbrother wrote:

Thanks for that Peter. I quite often go for a surf near there, Broadstairs (I'm in Gillingham). Will give them a call before I go next time. It would make sense for me being a light user, well until I do a resto on my van!
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replying to Leo Lichtman, 6G Jedi Master Open Root Assasin wrote: Not so, the welding procedure that map was used for and quite effectively was ALUMINUM TORCH WELDING theres a company that developed rods for this, but if you can't torch weld it wouldn't do any good youd just make a mess...... I just tried it with a bottle i got from the parts monkeys exited mistakingly thinking they now carried map..... Nothin doin not hot enough..... Well guess its time to find a Cobramatic Lil Green Giant ....Anyone have one for sale please hmu tiresmoker at Gee Meyl u know the rest.......and what's this about needing acyteline to Weld ??? What is this 1955 ?? What are u going to do with the acyteline ? I know your not talking about welding with it oxy-fuel torch steel welds are inferior, obsolete and eat up enough consumables to put u in the poor house... And saying the reason they still have acetylene around is u have to have it to weld steels is patently assinine at best .. They still have it around because it's cheap to produce and because there will always be shade tree ham & eggers who use it to cut pieces, and for the Ironworkers doing commercial erections where the asme code doesnt prohibit metal weakening torch cuts .. .. So Pony Up Greenhorn who buys his picante sauce in New York City on some 7018 Low Hydrogen rods and a DC machine or a couple car batteries wired in series
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replying to Peter Fairbrother, 6G Jedi Master Open Root Assasin wrote: Very Impressive you must be the brains of this operation... .. .. .. Do you know by any chance of a A/C amperage amplifier of some,type for 110/120 V A/C 60Hrz Current ?? I have an old craftsman electric push mower that ive restored and had to invest in a 50Ft 10AWG cord, and I plan on getting one more to be able to go out a little further, and i know the voltage drop will be substantial,
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