This is my first serious attempt at making a copper clad board.
I made the board from fibre glass mat impregnated with resin and then sandwiched between to sheets of MDF with Al foil to stop the resin sticking - the Al foil peels off the cured resin quite easily.
The problem is that it is quite hard to get the board perfectly flat even after sanding it. There always seem to be some divots that I can't seem to get out. And it is quite a bit of mucking around.
I have made some more boards out of thin masonite and smeared those with the same resin. This method of producing suitable boards would be much easier and quicker. And you can always find thin masonite or MDF on the backs of dumped furniture (re-use and re-cycle). I tried coating some scapr MDF with the resin and left it sitting in water for a couple of days - there was no sign of the MDF swelling due to water penetration.
Once you have your boards prepared you then need to make graphite paint. I got some graphite powder and mixed it it clear epoxy paint to a creamy texture.
Then I used a small roller to coat the boards. I did one coat but, after this current experiment, I would recommend at least two coats to make sure the board is thickly coated.
Then the next important step is to give the dried graphite pains a sand with fine emery paper to fully expose the graphite particles for maximum conductivity of the surface.
Then I immersed the board in copper sulfate solution along with some scrap copper pipe. The positive terminal of a battery charger was connected to the pipe and the negative terminal to the board.
It is important to include a 56R or so resistor to limit the current in the circuit to tens of mA.
If you don't the high current (3A or more) will prevent the copper depositing evenly over the surface of the board.
With this board, some divots around the edge prevented the emery paper reaching the surface of the graphite coating resulting in poor conductivity and poor deposition of copper.
I trimmed the board with an angle grinder however than caused a bit of de-lamination of the copper as you can see.
It will be far easier to get the smooth surface of the masonite totally flat and therefore the copper should deposit in a completely even surface.