in a bath of costic soda
The soldering stand has a wet sponge on it so you can wipe off and clean the soldering iron!
both
yes you can, so long as you clean the metal before hand like in usual soldering
You could try soldering
A: The pad is not clean it has tarnish or wrong solder with not enough soldering flux. Finally not enough heat.
You can buy one of several products from your local auto parts store that will stop a small leak in the front of the radiator... Now If you are mechanically inclined you can also mark where the hole is at and then drain and remove the radiator.. Once you do this you can clean the area around the pinhole and use a soldering gun and some 60/40 solder to permanantly seal the hole...
drainit
Make sure the soldering copper (tip) is clean and free of oxidation add some type of non acid flux and do not over heat
Defluxer spray, compressed air, or water.
you need to have it flushed
The radiator can be flushed with water running continuously. This will flush out any loose particles. The only way to completely clean the radiator is to have is professionally cleaned in a chemical bath.
you need to have it flushed