Bath Temperature Affecting Plating Speed

A. Telling you what to expect will detract from the importance of actually doing the experiment. I think you and your father will learn a lot more by doing it rather than reading it. However, I must give you one tip; do not use such a low temperature as 40F; I would suggest you start at about 60F. Different copper plating solutions have differing operating temperatures, but I suspect you will us the simplest acid copper (copper sulphate [on eBay or Amazon]with sulfuric acid and perhaps a bit of sodium or copper chloride). The plating rate for any metal is dependent on the metal ion concentration and hence the degree of dissociation of the metal salt. It is also related the rate at which the ions can be delivered to the cathode surface. Furthermore the rate is dependent on the rate at which the ions can be reduced to the metal; - this, to the greater part, is controlled by the current density, but there are other factors that you should be able to work out when you do the experiment. Your choice of copper will, perhaps, allow you see other effects, such as the effect of temperature on the properties of the deposit. You should see a change in hardness and possibly dullness of the deposit. As far as temperature is concerned, think what happens when you get hot - how do you react; the principles are exactly the same for ions!

A. For every rule, there is an exception. Common chrome plating with a 100:1 bath will plate faster at a lower temp than at a higher one IE: 120 °F vs 140 °F. Chrome is a terribly inefficient bath to use -- 15 to 20% of the current actually goes to deposition. Most of the balance goes into heat and gas generation. The faster rate also comes with a drawback, It is more difficult to control where the chrome goes (plates at) with conforming anodes.