Molasses Rust Removing!


Edsel Sending Unit

Mustang Drums



* Recent tests have shown that this process is NOT safe for Zinc Die Cast Metal, also known as "Pot Metal" Unless your goal is to dissolve the pot metal, do NOT immerse those parts in Molasses!!
It is not clear what other metals may also be affected by this process, so use caution.

Removing rust using Molasses uses a process known as Chelating. Without a good, scientific explanation, the process can be described as "Reverse Oxidation", wherein certain acids or chemicals in the molasses solution strip the oxygen from the Iron Oxide, leaving the iron behind. While I'm not absolutely positive about what exactly causes the rust to be removed, I am sure about one thing: It works.

The process is slow compared with other methods; electrolysis, various other acids, abrasives. Surface rust can be removed in a day or several, while heavy rust will require at least a couple of weeks. However, there are several advantages!

1. The ingredients are inexpensive. I purchased 5 gallons of feed-grade molasses from the grain elevator yesterday for less than $9, and that included a dollar for the container (because I didn't have one with me). This is enough to produce 20-50 gallons of solution (usually 1:4 or 1:10 is used).

2. There are no dangerous chemicals. Unlike some of the other methods, there is nothing that can burn your skin or eyes, and most other metals are unaffected, by this method.

3. There are no toxic by-products. The solution can be used repeatedly, for many months, but when it's time to dispose, you can safely pour out onto the lawn, where the molasses and water will decompose naturally.

4. It's effective. All oxidation will be completely removed, given enough time in the bath. The clean metal underneath will not be affected. For heavy rust it will take longer, and certainly a wire brush will help remove the large depsits, and help the process by allowing fresh molasses to come into contact with the rust.

Now, there are a couple of drawbacks. First, the process is slow. I've already mentioned that, but if you have more time than money, it's a great way to get rid of the rust on your restoration projects. Also, the Molasses solution smells like molasses. Even worse, once the solution starts to ferment, it will smell even more. I've tried using chlorine bleach to prevent fermentation and mold, but was unsuccessful. It's possible that the bleach evaporated out. I've read that people consider the fermentation process necessary for the process to work good, but I doubt that's the case. It will likely increase the acid level of the mix, but I expect the regular solution to still be very effective regardless. I may try the chemical that winemakers use to prevent fermentation in wines and see if that is effective.

Also, the parts will come out of the process with no protection from future rust, and the oxidation will commence again immediately. You must be prepared to clean the molasses from the parts, and protect the metal right away, either by painting, oiling, or or other means, otherwise your parts will quickly begin to rust again. I've soaked brake drums, heavy with rust for a couple of months (forgot about them) and after washing them with soap and water, they began to rust even before they were dry. Be ready to protect your parts!

Oh, and your parts must be degreased completely, since the solution does not cut grease, and the grease will prevent the solution from contacting the rust.