Small Oxy/Mapp Kit

[Pat Masterson]

Sorry if I’m putting this in the wrong thread guys but I thought this made the most sense. I was curious if anyone has ever used one of these small kits? And obviously what you thought of it. Of course to you guys with giant oxy acetylene set ups this is a joke haha but for someone like me working with 1/2” and smaller 99% of the time, I thought this might be pretty useful for localized heating - rivets, tight bends, upsetting etc etc. I simply don’t have the funds, or the space even if I did have the funds, to go with a real deal oxy set up. Thoughts?

 

[JHCC]

I see the appeal, but unless you're only using it rarely and for thin pieces, I wouldn't bother.

I took a look at some of the online reviews, and the general consensus seems to be that the bottles run out quickly, the flame is hard to adjust, it's good for brazing and soldering, and not much good for anything else.

It's been my experience that if something looks like it will do the job easily and cheaply but no-one's doing it that way, there's probably a pretty good reason why not.

[Irondragon Forge ClayWorks]

I have a set like that and about the only thing I use it for in the shop is to heat small rivets for peening them. Like JHCC said they run out of fuel & O2 rapidly and are expensive to replace the bottles.

[Frosty]

For the price of 5-6 of those you can buy a modest Oxy Propane torch set which won't run out of propane or oxy before it pays for another 50-60 of those little bernzYoWallet torches.

A $60, 160cu/ft bottle of oxy and a $20, 20lb tank of propane runs mine for quite a while. A few hundred rivets easy. I can't estimate how long it lasts, the 20lb. propane tank will out live 6-8 oxy bottles so I don't know why I included it.

The one thing it won't do better than oxy acet is gas weld, it doesn't weld worth spit.

Frosty The Lucky.

[Pat Masterson]

22 hours ago, JHCC said:

It's been my experience that if something looks like it will do the job easily and cheaply but no-one's doing it that way, there's probably a pretty good reason why not.

That’s what I was afraid of. 

I’ve seen little torch kits that are made to fit up to a regular 20lb propane tank. I always have a few tanks around so it wouldn’t be an issue to leave it hooked up to one and they’re cheap enough I wouldn’t be angry if it turned out to be terrible. With the material I use being as small as they are maybe just the propane would be enough. 

Thanks guys. 

[Ted Ewert]

I was in the same boat you were not so long ago. All you really need is a big oxygen bottle and a 20 lb propane tank like Frosty mentioned. 

I bought an old used oxy acetylene rig and then traded both bottles for one big oxygen bottle.

Having a good torch was a game changer for me. I use it a lot. 

[JHCC]

I would be using mine a lot, except I didn’t get a big enough oxygen bottle, and I just ran out!

[Purple Bullet]

Speaking of things that might work but you don't see anyone using - has anyone tried using an oxygen concentrator on a small scale? When I worked offshore there were large, expensive units but I see the small medical units go fairly cheap. They don't produce very quickly but I thought that with a large volume tank at low pressure (~100 psi) you would have an inherently safer O2 source that wouldn't require high pressure cylinders. I never use any higher than about 30 psi at the torch when cutting so as long as you aren't in a hurry it might work.

[JHCC]

As far as I can tell, home oxygen concentrators are designed to deliver 20 psi, with a maximum flow rate of about 21 scfh. For a regular oxypropane torch, that's barely adequate for heating and cutting thin material, and you're not going to be able to pressurize a storage tank to a higher pressure without additional equipment.

However, I do see a number of things online with people using oxygen concentrators to supply a Smith Little Torch set up for oxypropane. That's great for jewelers and other small work, but you'd have to think about whether that's big enough for the applications you'd be using it for.

[Frosty]

Before you convert a used or new oxy acet torch to propane is is NOT as simple as switching tank fittings! Propane is VERY chemically active and degrades the diaphram, seals and hoses rated for acet. 

Most new torch sets are multi fuel rated but be sure it comes from a manufacturer that cares about customer safety.

I thought about using a reverse osmosis oxygen generator but research showed the price of a compressor and hardware necessary to safely up the psi over 5-6psi generated by the medical generators (of the time) would keep me in bottled oxygen for decades. Buying an oxy generator that produced a reasonable volume and a psi running to 30psi was again enough to keep me in bottled oxy for a long LONG time. They wouldn't produce 30psi at their max volume either.

It's been at least 30 years since I was thinking about it so I wouldn't be surprised if prices have come down and suitability gone up.

Frosty The Lucky.

[Ted Ewert]

I'm wondering how hydroxy would work with propane. I know there are Chinese rigs for cutting steel. Maybe one of those would work all by itself.

Hydroxy has some interesting properties. I've heard that you can pass your finger through the flame and not get burned, yet still cut steel with it. It would be interesting to see how effectively it heats steel, and if it would be practical alternative. 

[JHCC]

Since hydroxy (properly “oxyhydrogen”) is simply a mixture of H2 and O2 gasses that do just fine generating heat from their own reaction, I’m not sure what adding propane to the mix would accomplish. If one were using an electrolytic fuel cell to split water into hydrogen and oxygen, there wouldn’t be any O2 left for the propane to burn.

Hydrogen is used as a cutting gas in industry, but its tendency to cause hydrogen imbrittlement pretty much rules it out for welding. 

[Frosty]

It'd be like adding some diesel to your gas tank. Mixing fuel gasses isn't done by companies who make their living providing high quality fuel gasses. Most who want to up performance refine propane further, cracking out the butane. 

The addition of acet to propane to make Mapp is the only exception I know of and my oxy propane torch is far more effective.

Frosty The Lucky.