Next test of my new PCB toner transfer technique. After getting the hardware ready and getting first awesome results I decided to make an ultimate test. I wondered if I can make toner stick to something that it didn’t want to before. I had a small sheet of copper clad board that is (no joking) older than me.I really don’t know the exact year when it was fabricated, but if I would have to make a wild guess – that would be 1980s at the very least. I got it from my grandfather ages ago.
That looked like a good test subject. Mostly because no matter how hard I tried – I could never make the toner stick to it a few years ago. So it was lying in a corner as the years passed by for a very long time, waiting for the time to come. Even more difficulties – the board will be double sided.
Before doing any lamination I threw the piece into the etchant for about 30 seconds. This cleared the copper clad board a little. Next I washed it, dried and got heated up the lamination machine. The latter didn’t really like the thickness (~1.5 mm) and it occasionally stalled the motor so I had to push the board a little bit so that it would get through. But despite the results looked promising and I got both layers aligned and ready from the very first attempt (WIN!). Etching took a while. It does look like the copper was quite thick.
Now, with that in my hands I cleared the toner with some acetone. Looks like a little bit overly etched in places. Must be due to the copper thickness – the thicker the copper – the more artifacts we have on the sides.
Now I applied the solder mask. Made with the same toner as well, the very same process. 
And populated most of the board. Turned out I ran out of mechanical relays that should be to the right. Besides that everything worked like a charm and looked really sexy. 
Later, with some added relays that looked even better:
Now, I should only give it a nice wash in C2H5OH and that’s it!
And yeah, I screwed up with text on the solder mask layer. Will do it right next time.