This is some method I found on the net for solving the problem of protecting the cooper of self produced PCBs.
What is done is the PCB is tinned before parts are soldered on it.
I discovered that this was exactly what I was looking for in order to solder a lot of small vias on more advanced PCBs with vias under the ICs.
In short: etch the PCB, drill the holes, make the vias, tin the PCB and you have a nice double sided PCB for soldering parts on 🙂
A more detailed description: