Compatability of EZ Torch with MAPP-PRO gas

I just got one of these from Otto Frei and was told by Steven Frei that customers had reported it getting clogged by MAPP-PRO. I realize that there is only a hundred some odd degrees difference between the current MAPP substitutes and propane, but every little bit helps. Does anyone have any experience with this who can shed some more light on it?

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I’ve never used this torch with MAPP-PRO gas, but I have used the EZ torch with Ametalene with no problems. Ametalene is a variation of propane gas that AirGas sells. I’ve assumed it’s like MAPP gas, but I’m not 100% sure? AirGas said Ametalene is what they supply to plumbers using atmospheric torches. I tried Ametalene for a bit, but now have gone back to a 1 lb propane tank. No reason for the switch except I wanted to test out Ametalene, but ultimately didn’t want a bigger gas tank in my shop.

I don’t understand why, but the EZ torch tips will clog over time with a gooey residue with all variations of propane gases. For me, it’s about every 3-6 months. 1 minute in an ultra sonic easily cleans the tips up. If you don’t have an ultrasonic, then a quick clean with dish soap, water and toothbrush will do the job as well.

Is there a reason that you’re choosing MAPP gas over propane? I’d recommend trying a 1 lb propane tank first and going from there.

Steve Frei was also the person who told me about EZ torch tips clogging with all propane-based gases. But again, I’ve found it to be an issue that just pops up occasionally. It doesn’t happen daily or weekly.

Hope that helps!


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Hi Jeff:

My only reason for considering MAPP-PRO was it’s making a slightly hotter flame than propane. I haven’t attached anything to my torch yet as I’m still lacking a number of pieces of soldering equipment. I do have an ultrasonic cleaner, which, if I understand you correctly, I’ll have to resort to anyway as propane itself will also clog the EZ tips. One of these days, probably before too long, I will in all likelihood make the switch to oxy/propane as I have found an oxygen concentrator reasonably priced at $480; for now, however, I’ll be using straight propane and hopefully not come up against its limitations for awhile.



Congrats on the oxygen concentrator! I’ve never used one, but they’re really popular on the forum.

The EZ torch is a cooler flame, but I really like it for jewelry scale objects. But I think you’ll also like propane/oxygen when that happens for you.

Good luck and keep us posted as needed!



MAPP gas was available in 1lb disposable bottles like propane, but is no longer available. It was a mixture of propadiene and methylacetylene and propane. MAPP pro which superseded it, is 95.5% propylene and 0.5% propane, with some formulations containing dimethyl acetone. Propylene will spontaneously but slowly polymerize into polypropylene plastic which accounts for clogging with gooey material, over time. All of these gases have 3 carbon atoms, but vary in the number of hydrogen atoms they contain (degree of saturation)… double bonded (unsaturated) hydrocarbons will tend to polymerize, causing clogging which shouldn’t be difficult to clean.
Ametalene, is a trade name for a mixture of propane and saturated 4 to 8 carbon molecules (butane 4 carbon, pentane 5, hexane 6, septane 7, octane 8)… the higher number carbon molecules burn hotter than propane as does butane, as they release more energy per molecule, but will also consume more oxygen per molecule. Double bonded carbon atoms will release more energy when burned than single bonded ones, with less oxygen consumed since the double bonds have more stored chemical energy than single bonded carbon. This does come at the expense of more fuel being burned compared to more oxygen with single bonded carbon atoms that are saturated with hydrogen atoms. Acetylene is a two carbon atom with a triple bond and only two hydrogen atoms. It burns even less oxygen at the expense of more fuel… the triple bond between the two carbon atoms is under strain energy which causes it to snap apart, releasing the most stored energy. That is why it also can be spontaneously explosive and has to be dissolved in acetone to stabilize it in the tanks that hold it…

For practical purposes, I don’t see much advantage of using higher energy content fuels than just plain old propane… as these fuels do not significantly raise the combustion temperature either in air or with oxygen, and at a much higher cost. The only exception, is oxyacetylene, which I have used for melting, where a high temperature results in quick melt and less oxidation…I also find it too hot to solder with without overheating the metal, unless done carefully.

I hope that I wasn’t being too technical, as this forum is one for artists and not chemists…

for the chemists among you, it also was an oversimplification, as the heat of enthalpy of combustion of oxygen and saturated hydrocarbons are higher than those of unsaturated molecules… temperature of combustion being a function of kinetics as well as enthalpy.

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PS: MAPP gas went out of production when the only plant making it was closed down in 2008. The amount of sales wasn’t worth the cost of restarting it at a new plant, when cheaper substitutes were available…the original MAPP gas was also deemed an occupational hazard by OSHA. Although MAPP gas burned at a temperature just a less hotter than acetylene, it was not satisfactory for steel welding, as it added hydrogen to steel, causing embrittlement. Union Carbide was the original manufacturer. Now Linde gas.

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congrants too on getting an oxygen concentrator. If you were using air and MAPP pro, you’ll find that oxygen and propane will burn at a higher temperature- 3,600 to 4,000 degrees F. That’s sufficient to do do everything. Also much cheaper to use propane with oxygen especially with a concentrator. Disposable oxygen bottles aren’t worth it… too expensive with too little oxygen.

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I think you’ve figured out another retirement job for yourself! Working for AirGas. I asked them what the difference was between Ametelene and Propane, when I experimented with it. They had no idea.

Also, I’m going to pass on your comments to some jewelry tool companies as they have no idea why propane gases clog up tips.



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Googling turned up this:

Does propane gas leave a residue?

Propane gas does not spill, pool, or leave a residue; this makes it harmless to soil or water if a tank were to leak. Propane furnaces can be up to 95 percent efficient, saving energy without you having to give up comfort.Jan 14, 2019

This makes some sense, since propane and the MAPP gases discussed previously are both organic molecules unlikely to be contaminated with anything but other gases like butane, pentane, etc.

Then I found this:

Can LPG be contaminated?

“Remarks concerning vehicle application issues like residues in vaporisers or injectors - The presence of plasticizer additives (e.g. phthalates) in elastomer hoses or other materials which can come into contact with LPG can lead to increased contamination of LPG by high molecular substances.

Based on these comments, I’m going to hazard a guess that the gunk may be coming from the hoses rather than the gases themselves. Perhaps contaminants that burn off in other applications using larger orifices gunk up the small tips used in jewelry work? Just a thought. -royjohn

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Finding the information is available on the internet. Just have to know where to search for the most relevant FACTS… the ASTM, ANSI, and multiple other professional standards organizations provide exact information about chemicals, steels, electrical equipment, industrial processes and about everything that is made industrially to standard.
There was a cartoon in the New Yorker several years ago where a man holding in iPhone was asked “if you were able to go back in time to the 1960’s, what would you tell teh people about your phone?” His response was that “I hold in my hand a device that contains all of the knowledge in the entire world… I use it mostly to look at pictures of cats and insult stranger…!!!” LOL!!!

But seriously, everything is available on the internet. Precise and factual information can be gleaned from the societies that set industrial standards, although it’s not necessary to go that much into detail most of the time.


My EZ Torch initially got “gooey”, but after a few cleanings, it got over it. As a result, I suspect that it is caused by the hose or manufacturing residue in the the torch handle. I use it all the time as an annealing torch because of the softer flame and lower temperature…Rob


Pure propane does not polymerize or leave a residue…unsaturated gases as found in MAPP pro do contain gases that will polymerize. If there’s a problem with pure propane, the source of contamination has to be elsewhere. If gunk builds up with pure propane, it could be coming from hose plasticizers or small of amounts of residual ethylene or propene (propylene) or other unsaturated low molecular weight carbon gases, in the gas. The latter would be more likely since propane is not purified to 100%…it’s produced by gas fractionation from natural gas…

According to the Gas Processors Association’s HD-5 specification for propane, it must consist of at least 90% propane , no more than 5% propylene, and 5% other gases, primarily butane and butylene.

Propylene or propene (the latter is the proper chemical name for CH3-CH-CH2, where the last 2 carbons are double bonded) and butylene (butene-1), C4, has double bonded carbon atoms that can spontaneously polymerize-- CH3-CH2-CH-CH2, with a double bond between the last to carbon atoms, butylene 2 (CH3-CH2-CH2-CH3, with a double bond between the middle two carbons) also can polymerize …butane is saturated and will not, with the exception that it propylene or butylene could react with it, but far less than with itself…The practical explanation is that contaminants in propane gas will more likely cause gunk build up than plasticizers in the hoses, I have had problems with the orifices on air propane torches, which are very small holes, clogging up. When that happens, the orifice is toast… can’t clean them… gunk build up with hoses hasn’t been a problem, but I suspect there’s gunk build up within them also, as a very thin film.

Couldn’t edit the post, but I wanted to mention that I always try to fact check, sometimes even as I write by using a second window.

The biggest complaint that I’ve heard about the EZ/Orca torches are the tips clogging. It took my EZ torch about 6 months for it to happen to me. And like I wrote somewhere, all that was required was about a minute or so in the ultra sonic to clean the tip up.

The reason it’s happens though I’ll it up to the scientists on the forum to theorize. I have found that it’s no big deal.

Like you Rob, I especially like the broad cool flame for annealing.



see my comments to Roy John… also note that proprietary gas mixtures may change in composition year to year depending of customer needs and sales…proprietary information won’t give out the precise mixture but only the general composition. what I wrote about “pure” propane comes from industrial standards. Even with standards, of 90% propane, the residual “impurities” can vary by composition with the source gas… i.e., wellhead to gas separation refineries… I have a friend who was a chemical engineer for Exxon who was able to give me a lot of information about petrochemicals. Polymerization of raw natural gas that contains ethylene is a problem for the pipeline carrying them… it’s also in crude oil, polyethylene plastic gums up the pipelines which have to be periodically cleaned by sending a “pig”, a large heavy ball, just the size of the inside diameter of the pipe, to sweep out the gunk by gas pressure pushing it along. It’s an old technology so I don’t know if it’s still in use or superseded by something newer. This more of a problem for gas pipelines than oil… natural gas is for household use is nearly pure methane, having been “scrubbed” but other 2 carbon and 3 carbon gases will still be present in trace amounts…not enough to gum up your stove or oven

Steve wrote:

When that happens, the orifice is toast… can’t clean them… gunk build up with hoses hasn’t been a problem, but I suspect there’s gunk build up within them also, as a very thin film.

I defer to you, Steve, as to knowledge of gas refining and impurity amounts and types in the propane or other torch gases (like MAPP mixtures). The impurities coating the hoses as well as being in the torch orifices themselves is an interesting twist I hadn’t thought of, either.
I am surprised that you say the orifice is toast, since the gunk should be soluble in some cleaner or other, no? As others in this thread have said, they use the ultrasonic, but I’d think some chemical solvent would work, too. The tip cleaners that welders use are obviously too large and too abrasive to use in our small jewelry tips…the gunk doesn’t corrode the brass, does it?

I have tried to clean them by soaking in solvent but not successfully… the orifices are pin hole so I can’t find anything that small to push thru them… it happens mostly after a period of heavy use followed by disuse for a long time…which is why I think the residual gunk is hardening. You used to be able to buy replacement tip orifices at the hardware store with minimal cost… now I think you have to buy the whole torch set again… cheap enough for the generic Bernzomatic type air/propane handheld disposable cylinder type torches but nothing’s cheap nowadays…haven’t had to look recently… my hand held has piezoelectric torch sparker that doesn’t work… never worked well even with low flow. but not a big deal, a cigarette lighter does it.
Thankfully the gunk isn’t corrosive… it’s plastic…polypropylene…the stuff that food storage bags and Tupperware are made of…I don’t think that the polymerization reaction generates organic acids as a side reaction, which would like vinegar or citric acid but less acidic…
I think of spontaneous polymerization of unsaturated hydrocarbons as the same thing that happens with polyunsaturated oils like linseed oil and cooking oil…boiled linseed oil makes good glazing on paintings to protect them… the painters used them to harden the paint into place… cooking oil does the same thing in my kitchen hood vent filter… gets thick and gooey…and harder with aging… and harder to clean.

My 2 cents worth on this topic… I have been using Orca/EZ torch for about 12 yrs now. It currently is the only torch set up in my studio and is the torch that I use with my students as well. I generally use 1 pound disposable propane cylinders and have occasionally used MAPP gas as well. I have 2 of these torches in my studio. I have never seen any “gunk” in my torch tips. In all of the years that I have been using the Orca, I have had to replace one or two tips, but this was caused by mechanical damage to the tips due to dropping the torch. I have never used MAPP Pro gas or Ametalene, so can not comment on those gases.
So while I agree that unsaturated gases can slowly polymerize, (I am a chemical engineer), I have never experienced this phenomena with propane and the EZ/Orca torch.
So my advice is stay away from the “Man Made” propane substitutes that are full of unsaturated hydrocarbons and stick with regular propane.


I only had the problem with bernzomatic air’gas torches… the orifice is very small, designed to create a venturi effect with holes around the base of the nozzle to draw in air.
100% agree that propane is good enough and far far far cheaper.!..if cheap gets the job done, stick with cheap.
the fact that the industry standard is 90% propane and 10% other gases including unsaturated still makes it cleaner.

to Milt: I really liked your exposition of weighing and burning propane with disposable 02 bottles… disposable oxygen bottles are far far too expensive to be worth using!!!

That sounds like great advice! When my EZ/Orca torch tip clogged I was using Ametelene. It hasn’t happened again since I returned that and went back to little 1 lb propane tanks.

Thanks for the tip!!