Category Archives: Cast Iron

cast iron electrolysis tank

cast iron electrolysis tank for cleaning rusted metal

After acquiring several old rusted up pieces of cast iron cookware we decided to get a cast iron electrolysis tank.  Some of the pieces were large, like an old dutch oven, so we wanted a large tank to accommodate it.  We had a plastic 33 gallon drum that held syrup for beverages that would be ideal for our job.  Any container that is not made from a metal will work.  The contain must absolutely be non-conductive!

The sacrificial metal for your electrolysis tank

A quick search of the topic on YouTube will show you lots of different metals being used as the sacrificial metal.  You will find everything from pieces of rebar all the way to pieces of old scrap metal.

To maximize the surface area available to attract rust from the item being cleaned I elected to use flat stock material.  It increases surface facing the item to be cleaned.  It also is easier to clean with a scraper and a wire brush.

Our cage was made so that when it is dropped into the tank it does not touch the sides or the bottom.  Admittedly I don’t know if touching hinders the electrolysis process.  I’m absolutely a novice at this and you should do your own research.  With that said, I liked the idea of the solution being able to freely circulate around our cage.  That is why it was built to not touch the container any where inside the solution

Cleaning the rusted item at regular intervals

While running our cast iron electrolysis tank I like to stop it every day to clean everything.  My assumption is that using a brush to remove lose pieces of rust from the item being cleaned and the superficial metal will speed up the process.

I’ve been running the electrolysis tank on the old cast iron Dutch oven for awhile.  Every day when i stop it for a quick cleaning I am seeing some great results.  It still needs some more rust removed but the water was so nasty and rust colored I decided to start over with some clean water.

At the end of each day the Dutch oven has come out of the tank and scrubbed with a brush made for washing drinking glasses.  The crud and rust that has come off after each scrubbing has been impressive.

The cage had a lot of rust built up on it when I removed it and dumped the water.  Most of the buildup came off easily with a wire brush.  While it was out we went ahead and hit it with the power washer.  Hopefully tomorrow the cage will go back in the tank and we will fill it and see how it does with fresh water and sodium carbonate.

Removing crud from the sacrificial metal

This picture of the cage was taken AFTER it was quickly attacked with the wire brush.  The bottom two steel bands looked just like the top one when this Dutch oven went into the tank.

electrolysis tank for cast iron
This is the tank we built to serve as our sacrificial metal in our electrolysis tank for cleaning cast iron

This was taken at the end of the first day of removing rust from the Dutch oven. You should have seen the water at the end of day 3.  That heavy number nine wire is suspending the oven in the tank and off the bottom.  The negative connector goes on that wire.

cast iron electrolysis tank and cage
electrolysis tank for cast iron working on that rust

While there is a lot of carbon on the bottom of oven in the next picture it is far better now than at the beginning.  When we started the entire bottom and most of the sides were covered with it.


And finally here you can see the inside of the old cast iron.  You can see the bottom of this old cast iron again!  When you compare it the picture that was taken at the beginning you get an idea of how much rust was removed.  There is still more work to be done, but I am satisfied with my setup.   The battery charger has been running at 2 amps during the process so far.  We could kick it up to 10 amp but I’m satisfied with doing this slow and easy.

The Dutch oven is out and I’ve dropped in a rough and rusted number 8 skillet.  After an hour in the tank I found this on the top of the water.

cast iron electrolysis tank removing rust
electrolysis tank for cast iron

You will need an automotive battery charger

Fortunately an inexpensive 12 volt battery charger works well for electrolysis.  My go to battery charger is a dual amp capable of 2 or 6 amps.  There are models available for less than $25 that will work for your electrolysis system.

You do not need a big and expensive battery charger to remove rust through electrolysis.  However, if you already have one it can certainly be used.

 

Electrolysis tank for removing rust from old cast iron

This project is one that I’ve been wanting to complete for some time now.  We have several pieces of old cast iron cook ware we’ve acquired that have a problem with rust and decided to try removal with electrolysis.   

An old plastic 33 gallon barrel that my brother gave me was perfect for the tank after cutting one end of of the barrel.  A local welder fabricated the cage for me using rebar and flat material.   I requested the flat steel to be used to increase surface area during the electrolysis process and to make it simple to clean up.

For our purpose we are adding one tablespoon of washing soda per gallon of water.  The electrical current is being provided with an old two amp charger.   Currently the old Dutch oven I’ve got in the tank has been there for less than two hours.  It has a long was to go but there is defiantly a noticeable difference in the amount of rust.  

My cage can easily be removed from the barrel to make cleanup and water changes as simple as possible.


Here you can see the flat steel bands that serve as my sacrificial metal.  It is easier to clean than a bunch of round rebar.  With a putty knife I’ll be able to quickly knock off the sludge that develops during the electrolysis process


Here ís the old Dutch oven that shows the level of rust before going in the tank.


The negative connector is attached to the wire suspending the item to be cleaned.  The positive cable is connected to my sacrificial metal, for my instance it is the cage I had made to fit inside my barrel. Do not use stainless or copper in any part of your build!

horse shoe trivets

Horse shoe trivets for dutch ovens

We had a local guy make some horse shoe trivets for us to be used with our Dutch ovens for cooking outdoors.  They hold the Dutch ovens up off the coals and are suited for baking cakes, biscuits and such.  The shorter trivet also works well for setting a lid on when you remove it to stir or add ingredients.

We used a bead blasting cabinet to remove all the rust and dirt before applying a black high temperature rust-oleum spray paint.  The ones that look silver in color are what they looked like after bead blasting.  They all received a few coats of black paint.

horse shoe trivets for a dutch oven
dutch oven trivets made from horse shoes
horse shoe trivets for a dutch oven
dutch oven trivets made from horse shoes
horse shoe trivets for a dutch oven
horse shoe trivets for a dutch oven

Why use a trivet?

Cooking in a dutch oven on a trivet allows you to better control the temperature.  To add more heat to your dutch oven, or other cast iron, one simply adds more coals around the trivet.  If your food is cooking too fast one simply uses a shovel or other tool to take coals out from under the trivet.

In addition to controlling temperature a trivet helps to keep dirt, leave or other debris out of your food.  By putting the lid on the trivet you don’t get dirt or grass in what you’re cooking when the lid goes back.

I’d like a trivet but can’t weld

If you can’t weld or don’t have access to one you have a few options.  You can hire a welder to weld up your horse shoes and stand for you.  You can find the horse shoes by reaching out to farriers, farms that board horses, Amish and Mennonite communities.  Interestingly enough, you can even buy used horse shoes on Amazon.

Lodge does make a stand for dutch oven lids.  I wouldn’t use it in place of my trivets to hold a heavy oven, but I do use one for my lids.  You can also find the dutch oven lid stand on Amazon or in the camping section at many Walmarts.