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If you are working on 8N tractors you will probably be working with some old parts that have set out in the weather, the parts may be covered in rust, grease, old paint, and other (possibly unmentionable) material. Search for Rust Removal on the web and you will find a wide assortment of solvents, strippers, oils, and converters. Most of these products range from mildly to highly dangerous to work with, so I stopped using them. They never worked as well for me as the label on the containers claimed anyway. Nothing seemed to work much better than plain old scraping, wire brushing, and sanding for me and those methods were basically free.
But then I came across some web sites describing one process that was supposed to remove ALL kinds of rust, grime, and paint using nothing more hazardous than washing soda. The process is called electrolysis and it is by far the BEST way I have found to clean all sorts of iron and steel parts. Even some aluminum and brass parts can benefit from a brief dunking. I started with a 5-gallon bucket. That was large enough to clean small parts that would fit in my powder coating oven and was a good size to see if the process would work for me. The setup is very simple. Fill your container with water (I used water straight from the faucet). Stir in about 1/3 cup of Washing Soda for each 5-gallons of water. Place sacrificial steel electrodes around the edge of the container. Hang the parts to be cleaned from a wire or chain in the middle of the container. Make sure the part to be cleaned is completly immersed in the water and does not touch the sacrificial metal at any point. IMPORTANT! Connect your positive lead to the sacrificial electrides and the negative lead to the part you want to clean. My setup is currently using a 30-gallon plastic trash can and a 2/10-amp battery charger. It costs almost nothing to operate, and "MOST IMPORTANTLY" it works on the rust while I sit and relax or work on other projects! Stick "rust removal electrolysis" in any search engine and it should take you to several pages of detailed information. TIPS AND TRICKSELECTROLYTE: Electrolyte is the washing soda and water solution in your tank. You only need about 1/3 cup of washing soda for each 5-gallons of water. That is enough to get the current flowing. Adding more washing soda will increase the amount of current flow, but does not appear to speed up the process. This is a case where more is not better, it simply wastes energy. The electrolyte will last indefinetly. If you have a lid for your tank to keep trash out, there is no need to ever dump it and replace it unless you want to clean the dirt, rust, and paint sediment from the bottom. A lid keeps bugs from dying in it and greatly slows evaporation loss. You don't even need to add more washing soda when you replace water lost by evaporation. Only the water evaporates, the original washing soda stays in the tank. SENSITIVE SKIN: The solution is basically the same as reaching into a sink full of dirty dishwater or your washing machine. It can be irritating if you have sensitive skin. But I often reach in and retreive dropped parts with my bare hand and arm with no damage. You will immediately be made aware of any cuts or scrapes, though. Rinsing with fresh water quickly takes care of that. Don't splash it in your eyes. BATTERY CHARGERS: My power supply is an old Sears Craftsman automatic battery charger. It has a switch to select 2 or 10 amp output. I use the 2 amp setting. This is another case where more is not better. Any current flow starts the process. Using the 10-amp setting just wastes energy and makes more heat. Some battery chargers do not work well for electrolysis. Electrolysis requires CLEAN DC power. Battery chargers convert 120 volts Alternating Current (AC) to about 14 volts Direct Current (DC) for charging. But, some chargers do not filter AC power as well as they should. Any AC power that gets through the charger into your electrolysis tank slows down or can even stop the process. If your system does not seem to work well, try putting a 12 volt battery in the circuit as shown on the following diagram.
STAINLESS STEEL: There are some warnings on the web that using STAINLESS STEEL for the sacrificial metal may create hazardous waste. Stainless steel would certainly last much longer and should work better than plain steel. But, the warnings claim that, as the stainless steel breaks down, it releases chromium and other toxic substances into the water turning it into toxic waste. I doubt if this is completly true. It sounds to me like one of those warnings that is only partially true. But I am sticking with plain steel for my sacrificial metal because I have an abundant supply of used welded wire fence fabric. This material makes a great sacrifical liner for my tank and has a much larger surface area than using a few pieces of rebar. It works great for me. MONITORING: Electrolysis requires very little monitoring. Iron and steel parts can be left to cook indefinitely with no damage. They may get a little warm, but the process only converts rust and loosens paint. Once all the rust is converted, the parts just hang in the vat with a little current going through them. I have often left parts cooking overnight. Be very careful with parts made with aluminum, brass, and other metals. Plated finishes could easily be ruined. I have not had any problems using my tank to remove paint from the few non-steel parts I have tried, but you could ruin some non-steel parts if you left them cooking unattended. LINE-OF-SIGHT: Electrolysis is a line-of-sight process. The sacrificial metal needs to be able to SEE the rust. Loose paint and dirt can block the process from working on the rust. Most paint is conductive enough to allow the process to work through it and loosten the paint, but I have found that it helps to pull the parts out and knock the loose stuff off. It can also be a bit tricky to get all the rust out of cracks and crevises. I usually have to do a little wire brushing and sanding before the parts are completly clean. NEGATIVE LEAD: PLEASE make sure your good part that you are cleaning is ALWAYS connected to the NEGATIVE power lead! Hook it up backwards and your vintage part will become the sacrificial metal. FINISHING: All rust is converted to a black oxide coating on your parts. If you are not planning to finish your parts immediately, leave teh coating on them since it is a pretty good rust preventative. Certainly better than nothing. Later, you can remove the coating or paint right over it. Your choice. Most of my parts still need some wire brushing and sanding before I feel like they are ready to be painted. Do the normal surface prep you would before finishing any bare metal parts. EXPLOSIVE GAS:YES! This process does generate hydrogen gas which is explosive if confined. DO NOT leave your tank running in an enclosed area. You need lots of ventilation. Better yet, set your tank up outside. Mine sits outside all winter and does not freeze because the salt content apparentlylowers the freezing point well below the average low temperature for VA.
This is my grill after an overnight dunking. You can see that it has a dark finish. This is the black oxide coating that is left as the rust is converted. Years of paint literally floated right off while I slept! It would have taken hours for me to clean around all those bars by hand. This is the largest part I have been able to do so far. It has a large surface area, so the current was a bit higher than I liked, even with my charger on the 2-amp setting. I checked on this one a few times to make sure nothing was getting too hot before leaving it to cook overnight. The biggest problem with large pieces is keeping them from making contact with the sacrificial electrodes. Electrical current will always follow the path of least resistance, so if the part touches your sacrificial metal it shorts out. This could ruin your charger. Some people have provided physical protection to prevent the sacrificial metal from touching parts. The best idea I have seen so far was to cut a piece of 3/4" PVC pipe for each piece of rebar. Drill a series of holes in the pipe about 1" apart and put the piece of rebar inside. The rebar can still "see" your parts through the holes, but the PVC helps keep them from actually touching. |
