Copper Electroplating part 2 (mixing the solution)


In part 1, we covered how to build the plating “tank”.  Now we’ll go through mixing our plating solution, using commonly avilable chemicals.

{snippet chemicalwarning}

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.

  1. Heat water (perhaps 70 C) – mainly to help the crystals dissolve in step two
  2. Fully disolve Copper Sulfate Pentahydrate Crystals in the water
  3. The water will now be blue – it is a good idea to let it cool before adding in the Sulfuric Acid
  4. Carefully add in the Battery Acid, mix thoroughly
  5. Add in Muratic Acid, mix
  6. 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.

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Posted in Prototyping and Fabrication
  • zizo

    can I use Salt instead of Muratic Acid?

  • Amir Allparts

    Wear eye protection. gloves etc . and be gentle!