Pencil Butane Torches for Brazing?

[redhatman]

Hey everyone, I am working with making a frame out of brake line and I have a propane torch and some lincoln electric flux coated brazing rods. I can get the brake line red hot, but the braze rods wont melt. I guess that is because im using propane and there is a lack of heat.

I was wondering if I could just buy one of those pencil torches that run on butane. I heard they get very hot. Does anyone know if I can use these? All input is greatly appreciated. Thanks
-Pat

 

[Mad Scientist]

There is no way you would be able to braze with a butane pencil torch. It won't get hot enough, and it won't hold enough fuel. You would have much better results with a setup that uses MAPP gas, and a micro torch.

 

[Cole82]

I think it's the rod you are useing.
This is what most use "Safty-Silv 56"
http://www.rccrawler.com/forum/showthread.php?t=24898&highlight=safty+silv

 

[redhatman]

There is no way you would be able to braze with a butane pencil torch. It won't get hot enough,

I thought these things got like 2000 degrees? Or is that false advertising?

 

[Mad Scientist]

Well, I suppose I really shouldn't say you can't braze with one - I have never tried it.

I looked up the flame temps in air of the four commonly used gasses -

Butane - 3,200
Propane - 3,450
MAPP - 3,650
Acetylene - 4,350

I am mainly skeptical because people have reported poor results using Propane, which burns hotter than Butane. Although this could also be contributed to other variables as well, I just am not sure if Butane would get the job done efficiently enough to use a pencil torch. Chances are, you'd be re-filling it way too often for it to be convenient. But hey, try it out if you want, a pencil torch and some butane are pretty cheap. And if it dosen't work, at least you'll have a nifty little pencil torch for various other uses.

 

[redhatman]

are you sure they burn that hot? I didnt think propane even got past like 1200. Because people say you have to have at least 1200 degrees for braze rods and they said propane woudnt cut it.

 

[thaclodking]

The butane torch just won't cut it. It may have a rated temp that would seemingly exceed the necessary requirements but the total output (volume) isn't enough to braze anything suitably sized enough for your intended use. Unless you are using brass and solder you will need to get a larger setup.

 

[Madcratebuilder]

Come on...all the smart guys on here. Any of the above gases well work IF you have sufficient BTU's.

A BTU, short for British Thermal Unit, is a basic measure of thermal (heat) energy. One BTU is the amount of energy needed to heat one pound of water one degree Fahrenheit, measured at its heaviest point.

 

[redhatman]

ok, i guess i wont get one of those. This is weird tho because i called up Magna, the company that makes my torch, and they said that It burns at about 1700 degrees farenheit. I thought that would be plenty enough? Then they said the MAPP Gas burns at about 2400 degrees farenheit. Wouldnt my propane torch be fine?

 

[quick5pnt0]

Propane just wont burn hot enough to braze. I've tried it before without much luck. You can get a kit at the local home depot that allows you to use those small blue propane tanks with the red oxygen tanks that will get more than hot enough for brazing. The biggest problem i have found with that setup is that the oxygen tanks run out much too quickly. If i were to ever try making a tuber again i'd invest in a good oxy/aceteline torch, because in the long run it'll actually save money.

 

[redhatman]

well good news. I got it to melt the braze off!! I then held the torch on there a bit longer to let it kinda sit on it. But after it cooled, I tried to pull the braze off the steel brake line and it came off pretty easily.

Is there something I should do to make it stick? I didnt use flux, and I didnt sand the metal or anything. Should I do either of those? Thanks for all of your help.
-Pat

 

[Mad Scientist]

Yes, by all means, prep your surfaces. Automotive breakline often has a galvanized coating, which is toxic when burned. You need to sand off the coating, and clean the area with some alcohol. Flux will help a great deal - it cleans the joint, and allows the brazing material to adhere better.

 

[RD400]

This is coming from the son of a man who was a welding inspector for 35 years.

You can braze with MAPP gas, but just barely. Even though the MAPP gas will burn at a temp hot enough to melt the brazing rod, it does have a hard time getting the tubing hot enough to flow it correctly. I use an OXI/MAPP setup. It burns up to 5600* +or-. Hot enough to cut 1/4 mild steel. It is much easier to braze with a torch that is to hot then one that is to cold.

As far as going through oxygen, I can make a chassis and go through 1 to 2 bottles. You only need to crack it open a little to get it hot enough to braze.

 

[redhatman]

ok, well. Like I said, I did get the rod red hot and got some to come off in pressure. Should this stuff just melt off like solder?

 

[RD400]

Yep, when I braze the tubing is hot enough to melt the brazing rod.

 

[1BadJeepBruiser]

I bought a MAPP tourch kit from lowes, it came with 2 bottles and the top which has a button that you click on it which will keep it lit for you without holding it in. I got it for like 50 60 bucks or something and it works mint. I did originall try using brazing rod that they sold at the store but it sucked. I went online and went to Ram Welding Supplies and ordered the harris safety silv 56 and a huge jar of white flux paste. I have been using this to do the exo on my 4runner and it works great. I always get the coating of the brake line by running it across the bench grinder which gets the coating off and roughs it up a little bit.


Mike

 

[Robb]

Go to Lowes/Home Depot, and spend $8 on a bottle of MAPP Gas. It will attach directly to the torch you are using on your Propane bottle. Dealing with the propane just isn't worth it.


edit: yea, like Mike said ^^^^^^^ :mrgreen:

 

[redhatman]

Go to Lowes/Home Depot, and spend $8 on a bottle of MAPP Gas. It will attach directly to the torch you are using on your Propane bottle. Dealing with the propane just isn't worth it.


edit: yea, like Mike said ^^^^^^^ :mrgreen:

I would just buy the bottle, but supposedly mapp gas is to hot and will melt my tip? Thats what the guy at the store said and that I would have to buy a new tip. I dont want to spend $30 on a new tip.

 

[thaclodking]

You won't melt the tip using mapp gas. The fuel and air mix in the torch tip but combustion takes place outside of the tip.