In part 1, we covered how to build the plating “tank”. Now we’ll go through mixing our plating solution, using commonly avilable chemicals.
We’re going to be using a 1 gallon plastic container, this should give us plenty of room for the boards we’re planning on plating. The chemical composition for the bath looks like this for ~ 1 gallon (this is based on the Think Tinker Copper Plating Solution):
|Distilled Water||.709 gal||2.683 L|
|Zep Root Kill (Copper Sulfate Pentahydrate Crystals – CuSo45H2O)||10 oz||283.5 g|
|Car Battery Acid (35% Sulfuric Acid)||.286 gal||1.0826 L|
|Muratic Acid (35% Hydrochloric Acid – HCl)||0.017 oz||.5 mL|
|Polyethelene Glycol (PEG)||.04 oz||1.134g|
Since battery comes in quart containers, we’ll be making ~.874 gal (32/36.608), so the proportion fo Sulfuric Acid is correct. The revised numbers for 0.874 gal are:
|Distilled Water||0.6197 gal||2.345 L|
|Zep Root Kill (Copper Sulfate Pentahydrate Crystals – CuSo45H2O)||8.74 oz||247.78 g|
|Car Battery Acid (35% Sulfuric Acid)||0.25 gal||0.9462 L|
|Muratic Acid (35% Hydrochloric Acid – HCl)||0.015 oz||0.437 mL|
|Polyethelene Glycol (PEG)||0.035 oz||0.9911 g|
PEG – 300mg / L . 1Gal of solution = ~3.78L 300*3.78 = 1.134g PEG
After plating an initial board, we added around 9 grams of PEG to the solution – briging the total to around 10 grams.
Steps to Mix the Solution
NOTE: Mix components in the order presented in a WELL VENTALATED AREA! Don’t breath in the fumes, wear safety glasses and gloves, protect your skin.
- Heat water (perhaps 70 C) – mainly to help the crystals dissolve in step two
- Fully disolve Copper Sulfate Pentahydrate Crystals in the water
- The water will now be blue – it is a good idea to let it cool before adding in the Sulfuric Acid
- Carefully add in the Battery Acid, mix thoroughly
- Add in Muratic Acid, mix
- Add in PEG, mix thoroughly
That’s it, the copper plating solution is mixed! Now we’re ready to activate the through hole walls and finally start plating some PCB’s – assuming a constant current source is available.