Comments from my life, family, and projects I enjoy.
Sunday, November 29, 2009
Yesterday afternoon I set up my electrolysis rust removal system. The reversal of the plating process. This consist of a 12 amp 24 volt adjustable dc power supply, a plastic tub from the dollar store and some scrap iron to use as the sacrificial anode. I keep the workpiece slightly raised off the bottom of the tub with a couple of bricks. The electrolyte solution is simply tap water with sodium carbonate (washing soda). Hook the negative lead to the workpiece and the positive to the sacrificial anode. I like to keep the battery clips out of the solution as the negative lead will lose it's plating and the positive will rapidly erode if they are submerged in the solution. The electron flow is from negative to positive, and the electrons will scrub off the oxides, paint and anything else coating the workpiece. The byproduct is rusty water with old paint and hydrogen gas. Yes, this does produce some hydrogen gas, so only do this in a well ventilated area. Avoid any sources of sparks or flame while running this process, and of course, No Smoking. You shouldn't be smoking anyway unless you happen to be on fire. A day or two in the "soup" will usually result in a perfectly clean part ready for primer after a vigorous cleaning with a green pad and tap water. This process is only for ferrous metals and should not be used on yellow metals or aluminum as they will disolve away. Rusty water with sodium carbonate is not particularly nasty for the environment on its own, but since I don't know what may be in the paint, I like to let the water evaporate and then dispose of the rust and paint in a well sealed plastic bag for the trash. I also avoid using stainless steel for the sacrificial anode as it contains chromium which is toxic to the environment.