I'd be a little careful doing this. The quick air blast to cool the metal borders on a quench which could make the material a bit less mallable and more susceptable to cracking later on. Not saying don't do it and I'm sure it may have worked for others without a problem and I may be overly cautious. I'm just throwing up a caution flag.

 

I understand small budgets! Being a commercial roofer my father didn't work much from Nov-Mar, but he was an A#1 scrounge. His work sent him to various companies sites, so you never knew what he was going to come home with! The rear wheels on the gokart were Piper cub tail wheels!!! I have no idea where he got those.

 

also note the usual cost for the yearly inspection is about 100$ tops and its usually cheaper to waste some gas and air to not have to pay the fee and reload early!
also on some lighter metal you might want to use solid mig wire which is the same thing as the brazing rods but come in a large spool from .024-3/32. i use the ER70S-2 rod for brazing and tig and my mig wire is the same thing just the letters are different the composition is the same

 

Note: brazing is a totally different process than welding. In brazing, a different metal (typically a brass alloy, hence "brazing", but other metals are sometimes used) is melted at a lower temp than the melting temp of the pieces being joined. An alloying takes place at the interface that typically penetrates no more than a few molecules deep. Dissimilar metals can sometimes be brazed together. Welding on the other hand is a fusion process. The pieces to be joined are brought to a molten state at the juncture. The filler rod, if used (filler rod is not required to be added to complete a sucessful weld) is a similar metal to that which is being joined and just adds additional volume of molten metal. The molten metal flows together to become a single piece at the juncture. Welding can only join like metals.

You only pay the inspection fee, which is required by FEDERAL LAW to be done every five years, if you own the cylinder and want to have that cylinder refilled after the last inspection has expired. The law prohibits the gas supplier from filling any cylinder with an expired inspection. If you EXCHANGE the cylinder, before or AFTER the inpection has expired you are not liable for the fee. There is no reason to exchange a cylinder that still has gas in it.
Now some suppliers do "loan out" tanks to high volume users without tank rental costs providing the tank is refilled within the specified contract period. This arrangement is usually refered to as a "demurage contract". If the tank is not refilled within the specified contract period (typically 1 year) then a penalty fee is charged. I think this type of contract penalty is what nixer is refering to @ ~ 100.00. In this case it may be more economical to turn in a partially filled cylinder rather than pay the demurage fee.

 

Maybe it was already mentioned in this thread or maybe I read it somewhere else (pretty sure it was here though) -

Brazing is probably the last thing we want to use on sheet metal or even a frame if we want to paint it afterwards as brazing doesn't take paint well.

I believe that's true and assuming it is, I think it should be stressed in this welding opus that ***** (and Ax) are putting together.....

 

That's true, paint does not like to stick to brass, and even less to the brazing flux.
Brazing is not nearly as strong as welding unless you use special high tensile rod, so it would not be used for anything structural. The major use for brazing in automobiles is to attach the vanes inside an automatic transmission converter. There a high tensile alloy is used and all the vanes are brazed at the same time in a furnace. As I mentioned brazing is sometimes employed where two dissimilar metal need to be joined. High temp silver soldering is a form of brazing as well.

 

Brazed joints need to be cleaned carefully - the one body pro we have said he went to sandplasting the joint before he spread filler and never had a come-back after that.

However, glue or brass is the only way to weld the new metal to the old metal that will always give you a strong trouble-free joint.