rust removal by horse feed

[VMC 81]

I have not tried cleaning chrome with this method. As for how long I have had parts in the soup for 3 days and some of the rust came off. But normally I leave it is for 1-2 weeks sometimes longer if I am not ready sometimes a month.

[VMC 81]

I put a  81 shelf in the soup and 2 weeks later I washed it off and now it is down to virgin metal

[BrianB]

Pretty darn cool!  I might have to give that a shot.

[mznb1u]

I think you would ge the same reaction if you used my mother-in-law's meat loaf!!! 

Just kidding of course.  That is an interesting process.  How did you learn of it and can anyone explain the science behine why it works?

  Tim

[VMC 81]

I heard about this ons automotive chat site. Not sure why it worls but has to do with the molasses reaction to the rust.

[Larry]

It's hard enough to find a horse, let alone horse feed in Chicago.

Very cool.  It appears to remove rust and the galvanized plating on the shelves.

Have you ever tried a painted surface?

How about warts, o.k. I'm kidding with the wart comment.

[Crazzy Canuck]

That is just awesome!!! If there are little bumps from rust, does it remove them as well and does it leaves pits where there rust was?

Thanks for sharing.

[vendo39]

Using molasses to derust parts is a very old and well known trick to people who restore old cars.  I have done it many times but keep in mind it is not some miracle process that is better than any of the other methods of removing rust.  From my experience, it is slow, it must be warm, it can cause pitting in some metals, it does not remove most paints or grease and you still have to scrub the parts after they have soaked for days or weeks.  On the plus side, it is relatively cheap, the molasses mixture seems to keep for a relatively long time and when you’re done with it, you can just dump it on your lawn.

There is a lot of information on the web about this.  I lifted this write up from some random site.  I thought it was close to what I believe or have observed.



Sulphated molasses has been used to remove rust from iron and steel for centuries. Possibly ever since the first drunken pirate dropped his flintlock in some on a Caribbean island as molasses is a byproduct of sugar cane.

According to a PhD Chemist friend the sulphur creates a weak organic acid. This acid does not attack the base metal as do the acids many of us are familiar with; sulphuric, muriatic (diluted hydrochloric), phosphoric (naval jelly).

The molasses must be the sulphated variety which is usually found in feed and grain stores as a component of horse feed. It is sold in 55 gallon drums but the stores will pour into your or their 5 gallon pail. Cost is roughly $15 for 5 gallons.

The other ingredient is water.

Ratios of 3 and 4 parts water to 1 part molasses work well. Less concentration will also work but takes more time.

The mixture will attack aluminum so do not use any for the container. Steel, cast iron and plastic are fine as long as they are clean. Start with warm to hot water and mix in the molasses slowly; making sure it is completely dissolved. Heat speeds up the rust cleaning process also so plan accordingly with the container selection.

During 90 degree summer days a block will be finished in 10-14 days; a bit less for heads. Sheet metal, small parts about 5-10 days.

The mix will often remove thin flaking paints but it has no effect on oil, grease, dried crud, etc. A commercial hot tanking would be ideal but is often not convenient. I use various solvents and a pressure washer as the alternative.

The concoction creates a rather nasty looking crud on the surface; it will also get quite ripe so don’t do this in the garage next to the wife’s car or laundry machines.

After 3-4 days to a week, remove the item, scrape off or pressure wash the crud and skim the top layer in the container. You will have to experiment with the process the first time or two to get a feel for what’s involved in a particular environment. A covered container is best but I've had decent results in even an open cast iron watering trough.

I’ve gone into the mix with bare hands at times but I suggest a pair of cheap dishwashing gloves.

The useful life is until it doesn’t work any longer. Cover it until needed again and top off any evaporated water. For instance, I've used one drum load for 5 blocks over a period of about 7 months. One guy forgot about a set of flatheads and left them in a barrel for 5 months, no damage.

Disposal can be down the drain or in the garden since it is environmentally friendly. For garden or lawn dilute with more water as it can burn roots; it is a powerful fertilizer. It also seems to keep root eating grubs away.

Besides blocks, heads, intakes, exhaust manifolds; I’ve cleaned straight axles, wishbones, wire and steel wheels, Model T sheet metal, tools and all sorts of other odds and ends.
It also does a good job on carbs but don’t leave them in very long; check daily. The same for general automotive pot metal once the chrome is stripped with a cyanide solution.

Blocks and heads will look like they were just cast, all water jacket scale is gone.

Since the cleaned parts are virgin metal they will flash rust quickly in a hot moist area. Wrap, prime, oil as needed.

[VMC 81]

I will tell you this I do not do any scraping or cleaning of the parts before or after I take them out of the solution. For the parts I just did they were in the soup about 8 days and in cold water. pulled them out and pressure washed them. And thats all. I have used the same solution for over a year and still works the same. If you have rust and pittted metal it will remove the rust but you will be left with the pits. As for paited items it will remove some of the paint just really depends on the part.

But it will clean the parts back to virgin metal and no sweat doing it. It would take you much longer to have to sand blast the part and is cheaper too.