MAPP + Oxygen question

[HauntFreaks.com]

I picked up a small torch, it uses disposable MAPP + Oxygen bottles... well I was doing some test brazing, then about 10mins in the Oxygen runs out... these were both new bottles.... does this sound right?? shouldnt it last longer then this??.... did I get a dud bottle? .... please let me know what you think??

[tat2INDY]

you might of gotten a dud bottle or you had the oxygen to high , you dont need alot to braze, your better off getting the portable ox./ac. kit from homedepot ,$299 i think, they last acouple hours , map gas bottles are hit and miss , and add up quick

[Robb]

The Oxy bottles don't last long...............and aren't needed for brazing the small materials we use on RCs. A simple MAPP bottle/torch will be all you need. Skip the Oxy.

[Mnster]

Yeah they last about 15minutes or so depending on the use. They add up quick as far as price. There were a few bone heads that returned empty ones at the local menards.

[crawlbe4youwalk]

Originally Posted by Robb

The Oxy bottles don't last long...............and aren't needed for brazing the small materials we use on RCs. A simple MAPP bottle/torch will be all you need. Skip the Oxy.

Oxy-Acetelyne and Oxy-Natural Gas are examples of Oxy-Fuel torches. In them pure oxygen is used instead of air. This is done to create a higher temperature flame. Since air is composed of about 70% nitrogen and 30% oxygen and since all gasses involved in the flame are heated to a high temperature it is apparent that using part of the heat of the flame to heat up nitrogen (which contributes nothing to the probuction of heat) is wasteful. so while it is possible to achieve high temperatures wit an air torch, you can do even better with an oxygen torch and there is no waste of fuel to heat nitrogen. It really depends on the material you are using. You can buy a cheap brazing rod or wire and it will have to be heated to over 1400 deg to melt. You can buy a smooth melting Harris Welco brand that melts at 1100 deg. The puddle flows smoother and your material will have less warpage. Hope this helps a little!

Nick

[ecoli]

Originally Posted by Robb

The Oxy bottles don't last long...............and aren't needed for brazing the small materials we use on RCs. A simple MAPP bottle/torch will be all you need. Skip the Oxy.

x2. If you're just brazing brakeline/thin steel and are using Safety silv braze, then don't bother with the oxygen. The safety silv melts quite readily using just MAPP gas.

[Double J]

Only use oxy/mapp for thick material that takes forever to heat up.
Other than that there is no use for the oxy.

I've had my oxy/mapp set up for a while and have only used it a few times for some thick material. total usage probably 7min maxx.

[HauntFreaks.com]

thanks for the info. guys... here is a pic of the torch i have... I would love to use it... very small tight bud on it... might look into a full size oxygen tank... please dont beat me up to much that is the first bead I've ever layed.... lol

[kaetwo]

What if the torch has an Oxy line, do you have to use it or can you just braze without the oxy setup. I have a Smith Mini torch and it's also Oxy/Mapp.

[HauntFreaks.com]

I know with the tips I have if there is no Oxy, its just a candle...lol

[Flynfrog]

HauntFreaks.com,
Which mini torch is that? -- Smith?

Flynfrog

[HauntFreaks.com]

Yes its a Smith.... I really like quality so far...

[frdtrkguy]

Originally Posted by Mnster

Yeah they last about 15minutes or so depending on the use. They add up quick as far as price. There were a few bone heads that returned empty ones at the local menards.

I recently got an empty Oxy. And I thought that it leaked out or something Now I see what most likely happened

[crawlbe4youwalk]

you will get a hotter flame with oxygen as the accelerant. You have to realize you are still using oxygen with mapp gas. The only problem with using just propane is your flame does not get as hot, and it takes longer to heat your product, less producing More metal fatigue and your braze may not hold. Your torch what they refer to as a jewlers torch. That is the perfect torch to use for brazing, good controlled small controlled flame.

[crawlbe4youwalk]

what size oxygen cylinder do you have. You all should get much more burn time than your getting. You need to make sure your not cranking the regulator up to high. I have pro plumbers that use a 20 c.f oxygen for brazing jobs and they can get over 30-35 minutes of continuos burn time on a 20 and a #1 acetylene, or mapp tank.

[HauntFreaks.com]

this is the bottle I used that lasted 15mins.... what size is a 20??... the flame that this torch produces is the size of a pencil point... kinda why I dont get why it would only last 15mins...

[crawlbe4youwalk]

1.4 ounces is nothing man. You need to get hooked up with a refillable 20 c.f oxygen cylinder. These will last you forever on a jewlers torch. If you need a price just pm me, I sell them!

[MasterShake44]

Originally Posted by HauntFreaks.com

thanks for the info. guys... here is a pic of the torch i have... I would love to use it... very small tight bud on it... might look into a full size oxygen tank... please dont beat me up to much that is the first bead I've ever layed.... lol

This is the same torch I use except mine is the older model with the brushed aluminum grip. This torch does produce an awesome flame, very precise and functional for brazing tubers. I just want a larger oxygen bottle. The disposable ones are too expensive. That's a good joint you have on the tubes, what brazing rod did you use?