Commercial PCB washing solutions are relatively expensive, much cheaper and still powerful one can be prepared at home. It's based on trisodium phosphate, highly alkaline substance able to reduce oxides and react with grass forming soaps. Soaps in chemical meaning, not something we buy at store.
A sample PCB smashed into two pieces - on the left original state, on the right washed up.
- trisodium phosphate - 1,5g
- water - up to 200ml
The procedure is simple - a PCB is just placed into the solution and shaken from time to time to speed up the cleaning. Heating is not needed.
I'm using a cheap ultrasonic washing machine - I still don't know if it's working or if it's just a placebo and a bit of a noise, but it seems that at least it mix the water. I've placed the mixture into a glass and then placed it into the water in the washing machine. This is less efficient, but device is easier to clean after use.
Note: trisodium phosphate is highly alkaline - it's visible on below below on below universal indicator. Use protective glasses and gloves.
In case of skin contact, wash the solution wash it with a lot of water. In case of a skin contact with the powdered substance whip it by using a rug and then wash it.
Trisodium phosphate was widely used till 70's, it's an inexpensive and effective cleaning agent, but is not environmental friendly.