Bronze filler.

[hotrodder]

Silicone is used to ruin the shape and feel of ladies funbags [/pedantic], silicon (and a little Mn) added to copper lowers the melting temp, improves mechanical properties and helps 'mop up' any oxides

How would you select filler rod diameter. Cheers.

Thinner material = thinner wire... with TIG the heat source is waaaay more focused/concentrated than with oxyfuel making it more difficult to melt and wet out the wire without melting the base material if the wire is too big. While 1.6mm is usable on 0.9 - 1.1mm sheet steel, 1.2mm silcopper or phosphorbronze makes life easier. On thicker stuff can just feed more of a thinner wire to build up a larger fillet or whatever

 

[ronan]

You don't have to quench copper to anneal it, air cooling is fine. Welding it will get it well beyond dull red, then when cooled down it would be annealed.
AFIAK, the only way to harden copper is work hardening.

Don't it age harden too ?

 

[ronan]

I googled this bronze filler/tig brazing thing yesterday, some people swear by using bronze filler using ac, and as many using dc. The dc appears to give a neater weld. What i want to know is, is it any good for cast iron ?

 

[Maker]

Don't it age harden too ?

As I understand it, age hardening, AKA precipitation hardening is caused by impurities/alloying elements precipitating out, therefore a pure metal cannot harden like this because there are no other metals present, I might be wrong though.

 

[TechnicAl]

As I understand it, age hardening, AKA precipitation hardening is caused by impurities/alloying elements precipitating out, therefore a pure metal cannot harden like this because there are no other metals present, I might be wrong though.

No youre correct...........copper work hardens

 

[hotrodder]

I googled this bronze filler/tig brazing thing yesterday, some people swear by using bronze filler using ac, and as many using dc. The dc appears to give a neater weld. What i want to know is, is it any good for cast iron ?

Yeah, can braze CI with TIG. Personally i'd put it ahead of brazing CI with oxyfuel but behind MMA with a nickel iron electrode and a hammer

 

[ronan]

Yeah, can braze CI with TIG. Personally i'd put it ahead of brazing CI with oxyfuel but behind MMA with a nickel iron electrode and a hammer

What i would mainly be brazing , made of cast iron would be things like motorcycle cylinder fins, no real strength needed.

 

[hotrodder]

that's messed my order of preference up. Didn't think about finned heads/barrels as 99% of the heads i see are ally, yeah i'd TIG braze 'em unless it was for some matching numbers nutter whining about colour match in which case i'd pluck an obscenely high price out of the air and hope he goes somewhere else

 

[Chris Stevens]

I googled this bronze filler/tig brazing thing yesterday, some people swear by using bronze filler using ac, and as many using dc. The dc appears to give a neater weld. What i want to know is, is it any good for cast iron ?

Done lots of cast iron repairs with TIG brazing, which has worked well on all that I have done. The only time you would want to use AC if is you are using aluminium/ bronze rod, I have used SIF phosphor bronze No 8 on everything from head fins to exhaust manifolds, and no problems at all. MMA is probably better for much heavier castings, but would say that there may well be a need for careful pre-heat and post cool in relation to this type of repair, so maybe not work to be undertaken without that in mind?

 

[ronan]

Really, you can TIG braze with pure copper wire? Any special tips and tricks? I'm gonna have to try that.

A tig time video featuring Mr.tig tig welding copper using tig vision. Apparently you really need to use 100% helium to get the heat into the material.

 

[mtt.tr]

Found pure copper hardly flows but it works.