Okay, I have wire wheeled the spots where there was rust to the bare metal, there are some small pits of rust left that the wire wheel couldnt get, what to do next?
A good primer? vinegar? recommendations? im going to put sound deadening kilmat over it, so the looks dont really matter just want to not have rust come back
that rust isn't terrible, any kind of rust stopper should do the trick. If you're not in a hurry, I recommend using boiled linseed oil (it takes a few days to fully cure).
Ospho (phosphoric acid) will convert any rust you miss to iron phosphate and stop it from spreading. The thinner the rust is, the better it works.
This will not affect bare metal without any rust. All rust encapsulators work with (generally) the same chemical reaction iron oxide + phosphoric acid-> iron phosphate + inert other stuff (it's too early for me to do analysis). Ospho is probably the cheapest.
You can wipe bare metal with a damp cloth to encourage flash rust and then treat with Ospho (this is the method recommended by POR-15), or apply primer, but don't apply paint to bare metal (unless it includes primer). The advantage of using phosphoric acid is that the iron phosphate is chemically bonded to the base material much tighter than the primer will.
Typical primers bond by adhesion; you have to use a self-etching primer to get chemical bonding.
