I live in Byelorussia, I am interested in welding by gas MAPP. Ask to give council where it is possible to receive the free-of-charge information on work with this gas. I thank.
This continuation of discussion of a theme. Excuse my computer for translation quality. I hope, it all the same can be understood.
I work with gas MAPP two years and I think his(its) perspective enough for welding and cutting of steel. The basic condition of his(its) application for welding is application of a welding wire with the raised(increased) maintenance(contents) of manganese and silicon, for neutralization of superfluous oxygen. We use gas MAPP for welding at construction of houses, for repair of automobiles and for other works.
It would be desirable to receive the message on successful application of gas MAPP from you. You apply what equipment and, that you advise for success.
Most everyone on this side of the pond went throught the learning curve with this gas. Personally, I think it is not worth the money for cutting, heating or welding.
I must confess my ignorance. What does it mean MAPP?
Giovanni S. Crisi
Sao Paulo - Brazil
MAPP is Methylacetylene Propadiene, a fuel gas used in place of acetylene. It is more stable and can be used at full cylinder pressure (although I don't know of any reason to do so) unlike acetylene at pressures above 15 psi.
CHGuilford
I was told many years ago its the cheapest of gases and is equivalent to sewer gas with a few additives.
Back in the 80's, the welding supply houses were trying to market this stuff, nobody liked it for one reason or another. I tried preheating with it on some heavy base plates, I wasted a lot of time, give me bottle of propane and an ol' weed burner for preheating. It also made funky cuts on steel, lots of slag and dross. Spent more time grinding the garbage off also.
Never tried to weld with this gas, nor would I want to.
I don't know anyone who uses it in this millenium.
Probably, you used not so good equipment for cutting. As a rule quality of cutting depends on the equipment and cleanliness of oxygen, instead of from structure of warming up flame. We use the equipment of the design for cutting and we receive excellent result at work with gas MAPP.
Vasiliy.
At increase of pressure of acetylenes it is capable to blow up spontaneously. Therefore it(he) is not suitable for underwater are sharp. MAPP well works on the big depths.
Vasiliy
I once worked in a large shop where we built oil rigs from heavy steel. We use Mapp gas on everything from 1" (25mm) thick and lower, in order to save money, but used Acetylene for above 1" because the MAPP gas would not make clean cuts on the thicker material. Everyone prefered Acetylene over MAPP, but the MAPP works OK once you get used to it. Also, Mapp gas requires a special, two piece cutting tip that does'nt last very long.
If you consider that it takes twice as long to complete a cut with Mapp as with Acetylene, and you have to buy a lot of special cutting tips, and you have to spend more time grinding, I don't see purchasing MAPP gas as much of a cost savings over Acetylene.
FUEL GAS MAPP
THE BOTTOM, LINE I DONT BELIEVE INDUSTRY NEEDS THIS FUEL GAS MIX, IT OFFERS NO BENEFITS TO PROPANE
MAPP C3H4
METHYLACETYLENE PROPADIENE
MAPP IS STABILIZED WITH
PROPANE ISOBUTANE ISOBUTYLENE
MAPP 1-lb = 9.06 cf 0.25 cu m
1kg = 19.9 cf 0.56 cu m
MAPP MOLECULAR WEIGHT 42.3
VAP. HEAT 227 btu/lb 0.53 MJ/kg
MAPP TOTAL HEAT OF COMBUSTION
21700 btu/lb 50.5 MJ/kg
MAPP BOILING RANGE 1 atm
101.3kPa = -36 -4oF / -38 -20oC
MAPP FLAME TEMPERATURE IN OXY
5301oF 2927oC
MAPP AUTO IGNITION TEMPERATURE
IN AIR 851oF 455oC
MAPP FLAME VELOCITY
15.4 ft/sec 4.69 m/sec
MAPP FLAMMABLE LIMITS IN OXY
2.5-60%
MAPP FLAMMABLE LIMITS IN AIR
2.5-11%
MAPP VAPORIZATION PRESSURE
70oF 21oC = 94 psi 645 kPa
MAPP SPECIFIC GRAVITY GAS
60oF 15.5oC = 1.48 AIR=1
STORAGE EQUIPMENT FOR MAPP
SAME AS PROPANE
MAPP SERVICE LINES
IRON - STEEL ALLOY - Cu OK
DON'T USE Cu CONTAINING
MORE THAN 60% Cu
REGULATORS TORCH MANIFOLDS
VAPORIZERS - USE MAPP APPROVED
Above info taken from http://www.weldreality.com/, a GREAT SITE, especially for GMAW and FCAW enthusiasts !!!!!!!!
Been there done that. We have gone back to acet.
MAPP benefits
Bottles are DAMN lightweight, I miss picking a MAPP bottle up, REALLY!!
Can take great pressures
Not as explosive as acet if leaked in shop
less expensive
Thats ALL
Negatives
cannot be used for all oxyfuel welding and brazing
tips are OUTRAGEOUS and TERRIBLE to maintain and DO NOT LAST
DOES not cut heavier steels as well as acet.
Is cheaper than acet for heating but propane is just as good, however if weight is an issue I will admit a MAPP bottle is much lighter than both
My opinion
If you are only cutting, need maximum mobility or underwater capability its viable,
otherwise, go with acetylene. I do wish I could pick an acet bottle up like that though!!!
good luck !!!
Greetings to all.
It would be desirable to continue a theme. Thank for the data from the directory, but me would be desirable to read opinion of the skilled welder. What equipment is better for applying? What receptions of welding should be applied to elimination of some lacks of gas? If it is possible, give the address in the Internet on sites connected with gas welding
go to www.weldreality.com
you will have to look under consumables
then fuel gasses, its all there
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