Using brazing rod for small parts - good idea? ..and what about the flux?

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awake

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I've used 1/16" and 1/8" brazing rod for small parts but I think it is not as soft (harder) as 360 brass rod. Can anyone comment or verify?
Hmm - perhaps work hardened from the drawing process. Have you tried annealing it?

You should be able to get bronze TIG rod at a welding supply .
Note that TIG brazing rod is a different alloy (silicone bronze) than gas brazing rods and never have flux on them (flux would be counterproductive in the use of TIG). Whether or not the difference in alloy matters when using some as a part in a hobby machinist project ... that is, of course, for the machinist to determine!
 

VicHobbyGuy

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Update: I bought some brazing rods on clearance and, as reported, the flux is easy to remove. I just soaked the rods in a bucket of water for a few hours and the flux came off with a Scotchbrite pad.
 
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On the subject of removing fluxes.... many fluxes are in one chemical state when in a powder form, but "activate" when heated to melt/ liquify. Then when they cool, the mixture of un-used flux and chemically changed flux (from taking the oxygen from the oxides) forms a ceramic. Usually, this slag can be either knocked off as it is mechanically brittle, or washed off by soaking in water. Be careful. The shards from brittle slag are hard and sharp like glass. The chemical solution of flux and oxidised flux is corrosive, so can cause chemical burns. Read the safety data sheet before playing around with this stuff.
Hard to remove slag may be dissolved in acidic wash, such as an acid pickle. I use central heating descaler.... but some slag can take a week of soaking to become loose enough to wash-off. I have never found a slag that won't succumb to pickle solution.
Toymaker, I have not found a specific reference telling us what alloy rods you used for the aluminium joints of your Freon spray bar?? Can you help please?
Ta.
K2
 

Bentwings

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. I may have been misleading yes. No flux needed unused silicone bronze mostly for the copper Rc functioning scale exhausts also used on some very thin stainless. However I had double regulators so back purging stainless was easier than just using thin rod I just sold my Lincoln 275 square wave welder plus almost all ofvthe rods I had considering I leased it to a company I worked at right after I got it then got paid to use it it didn’t owe me anything. I guess I scored on this one . LOL one thing that is rarely noted is most TIG welders have a very short higher amount start than you Tink it only lasts a moment but when welding very thin materials this can make poor starts and burned holes . The way to get around this is to have a copper starting block . You start the arc on the copper then quickly move to the area you are welding . Some old timer told me this even with a pedal start and the welder set on very low power it’s still enough to make a fault in the weld. I did a lot of aluminum fuel and oil tanked on racers lots o edge welding. Another thing this guy showed me was doing just the opposite when tack welding edges start the bump up the power or pre set it . With practice you get so the tacks are in just the right spots so you can full penetrate weld the seams. He was very good gas welding aluminum . I never did get good with this even with all the best equipment . The TIG welds worked very well but gas nope don’t bother . Welding or silicone brazing copper was tough . Copper soaks up heat like a sponge so you either build in heat sink or have to stop and cool it befor it degrades from excess heat
Hmm - perhaps work hardened from the drawing process. Have you tried annealing it?


Note that TIG brazing rod is a different alloy (silicone bronze) than gas brazing rods and never have flux on them (flux would be counterproductive in the use of TIG). Whether or not the difference in alloy matters when using some as a part in a hobby machinist project ... that is, of course, for the machinist to determine!
 
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