To FLUX or not to FLUX

[dburly]

I use only silv 45 on copper to steel joints, been talking to another tech who uses 45 and white flux. I don't like the idea of any thing getting inside of the refer system which I'm sure some of the flux does.
Are there any standards on this practice, or is up to the individual.

[maxster]

FLUX IT...your hitting the pipe with a 1500F flame clean and quik next joint

[dburly]

No worry about the flux contaminateing the system? . Ya thats the reason he says he uses it for the quicker process.

[CHLR618]

Always use flux - makes for a quicker-cleaner and solid joint. I've done it this way for years and never had a problem.

[dgruber]

I have used flux for this type brazing, as you mention, for over 25 years.

No need to worry, except, clean the outside of the brazed connection as best as possible once completed.

I usually clean with water then sand off or file off any excess flux. Otherwise, you will have corrosion set in over time. Plus a good visual to make sure you have capped the brazed joint solid! Telescopic mirror a must.

Make sure you leak test!! After the repair you should evacuate, so make sure you are leak free or otherwise you will introduce moisture into the system!

Depending on how you can isolate the system, you could always run nitrogen through the system while you braze which will prevent oxidation inside the piping. This is always a good practice, but rarely performed including myself! Evacuate the isolated portion of the system after nitrogen has been introduced into the system, to make sure all non condensible's are removed.