brazing questions

[RebelRacer]

i had a couple of questions that i cant seem to find the answer to about brazing...

why does everyone use brakeline? is there anything else you can use and/or is it that its just the strongest thing.

ive brazed copper pipe together using copper phosphorus brazing rod and a mapp torch without using a flux paste... is flux paste a must use thing and would the copper pipe be strong enough, only looking to build some bumpers for now..

Can brass pipe be used?

Just dont want to spend a fortune on safety sliv, wire and brakeline... looking for a cheaper way. any information/opinions would be greatly appreciated

 

[Szczerba]

I just learned to braze last weekend and used flux coated 3' (~$1.50ea) bronze brazing rods from the autoparts store and 3/16" (~$4 for 3') solid steel rod from Lowes. I did clean and flux the joints before hand to make sure they were clean but with the flux coated rods you probably dont, i just wanted too.

 

["N8"]

You can make a tube chassis out of anything you like. Copper and brass are super heavy, soft, and expensive though. Steel break line is usually used because its cheap, strong, and abundant.

Flux must be used as it removes impurities in the braising joint.

Good luck.

 

[vw_thing]

Brakeline is cheap and can be found at any auto parts store. It is certainly not the best or only metal you can use. Copper or brass will do just fine if you prefer working with them. Safety silv is only one of a huge list of brazing rods. Silver rod does have better flow and can join dissimilar metals, but is more expensive and requires very close fitting joints. Brass rod melts at a higher temperature, and gives a little less flow with a higher fill.

If you are doing things "by the book", you want to use flux for any kind of brazing. You can often get away with a very good cleaning, preferably chemical, but flux will always help joint purity. Flux coated rods are good and bad. They are convenient, but any moisture or cracks in the coating will ruin the rod (big concern among stick welders). Try to store them in an airtight tube and use them within a month or so. A can of heat-and-dip flux will last a very long time, and isn't that hard to get used to.

Clean joints are important, flux or not.