How to stop rust in metal water barrels?

Greetings,

Not sure if this is the proper subforum but here goes.

I am attemnpting to heat and cool my greenhouse using 3 55 gallon black metal drums connected together and cycling through a radiator with a fan behind it. Similar to https://northernhomestead.com/car-radiator-for-heating-and-cooling-a-greenhouse/

The problem is its producing a ton of rush. Any ideas on how to treat the rust or stop it, or am I doomed to have them rust out? I went with metal as it absorbs the heat from the sun much better than plastic.

Thank you,

Hi Brent;
I am not aware of any product to stop rust forming. I could be wrong.
I think you should expect these barrels to be good for a few years.
Long enough to see if they do the job for you.
At that time I would replace them with the plastic barrels.  I would think a black plastic barrel  would do almost as well as the metal ones.

I run a micro hydro. The first 5-8 years I used several metal barrels as my water dump. About 2-3 years before they rotted thru.
In the 20 years since then I have bought one plastic barrel and it is still as good as the day I bought it...

are you opposed to using a Polyethylene Plastic drum liner?

https://www.mcmaster.com/9772T29/

You could use a corrosion inhibitor like they do for outdoor furnaces... something like this one. https://altheatsupply.com/wood-furnace-parts-accessories/maintainance-treatment/inhibitors-rust-scale.html

You could use a liner, they make them especially for metal barrels.  Another way would be to use neutralized distilled water, that would shorten the speed of rusting.

thomas rubino wrote:Hi Brent;
I am not aware of any product to stop rust forming. I could be wrong.

Yeah they make them. I did a quick search and could not find one though.

We use them on big tanks at electrical powerplants for the boiler water. Its just an electrical box that converts power to very low amperage power that basically is electrolysis. The higher voltages clean the rust from the steel, but this just induces enough current to keep rust from forming on tanks to start with. I am talking a whopping half an amp of current.

They might even be affordable and available for home use. They are small, about the size of a kids lunch box and just attach to the steel tank by a wire. It looks like a grounding nut but its just half an amp of current to upset the chemical reaction that creates rust.

I am sure a homemade version can be made, I am just not sure what they are called. I am no longer involved in boilers but instead operate hydro stations.