That is why you have to preflux the tubing and fittings before you solder the joint.WRONG,WRONG,WRONG
Hercules as well as other companies are now offering (now means over 30+ years ) a solder in FLUX form that is a one step operation.
As a “plumber” I braze copper with a silver bearing rod with NO FLUX required as the siver content acts as a wetting agent and thus it is considered self fluxing
Any good plumbing manual will tell you not to use a core solder for sweating pipes.WRONG ,WRONG,WRONG
Rosin core is NON acid and thus rosin is one of the “approved” fluxes used in soldering COPPER,lead etc..
I know for a fact Rosin core solder in the hands of a semi skilled mechanic can solder a very decent joint.
This is especially true on working with old copper drainage lines where it is not possible to remove all the oxidation
The most likely problem when having difficulty with soldering is joint not cleaned enough (that is why the Rosin core works wonders)
The regular flux (soldering paste could be contaminated)
You either over heating or under heating a joint.
» This message has been edited by SylvanLMP on 31 January 2002