Rust removal with molasses.

I thought I'd give it a go myself. I have some badly rusting 101 parts that I want to remove the rust, stop the rusting and then measure them up so I can draw them up and get them re-manufactured from gal.
Attachment 30199
I bought 2.5kg of molasses from the local stock feed suppliers round the corner for less than eight dollars. I put half of it with four litres of water and mixed it up well. I put the two bits of mostly rust in about midday today. I have just checked the progress and noticed some very fine bubbles of gas above where the parts are.
Attachment 30203
Evidence of a chemical reaction taking place.

Oh and it makes the laundry smell nice if you like the smell of molasses.

DON'T place Any none ferris metals in molasses as you wont get it back. It converts allay and brass to a horrible sandy mess in the botton of the tub.

hodgo

I'd be interested to see how these come out - keep us posted on the progress...

Cheers - Gav

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Originally Posted by hodgo

DON'T place Any none ferris metals in molasses as you wont get it back. It converts allay and brass to a horrible sandy mess in the botton of the tub.

hodgo

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I'll be testing that. There are the remnants of some rivets in the parts I've put into the bucket.

That is a pretty strong brew Mick!

1 part molasses to 10 parts water is usually strong enough. Quite often one can see the outline of the part in gas bubbles on the surface :D

Cheers Charlie

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Originally Posted by chazza

That is a pretty strong brew Mick!

1 part molasses to 10 parts water is usually strong enough. Quite often one can see the outline of the part in gas bubbles on the surface :D

Cheers Charlie

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Molasses is cheap. Less than a medium Big Mac meal deal.
There was a lot of rust.
Do you think I should dilute the solution?

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Originally Posted by Mick_Marsh

Molasses is cheap. Less than a medium Big Mac meal deal.
There was a lot of rust.
Do you think I should dilute the solution?

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Used to be cheap. 200 l for $25 direct from Nambour Sugar Mill.

Damn site more expensive than that now.....if you can get it.

20 Lt tub from my local stockfeed/hardware store was $32 last weekend but I'm a long way from where any sugar cane is grown.

Regards,
Tote

Gleamed from another site:

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Question
I have a friend who uses molasses to clean rust off old iron items collected from the bush. The rusty iron article is placed in a jar of molasses solution (nine parts water, one part molasses) and left for two weeks. After this time, the article comes out clean and almost shiny. What is happening here?

Answer
Molasses contains chelating agents. These are made of molecules that are shaped a bit like the claws of a crab--the word chelating comes directly from the Latin word chele, meaning claw. They can envelop metal atoms on the surface of an object, trapping them and removing them. Molasses owes its properties to cyclic hydroxamic acids which are powerful chelators of iron.

More of these compounds are found if the molasses is derived from sugar beet rather than cane sugar. The plants from which molasses is made presumably use these chelating agents to help them extract minerals from the soil. Interestingly, there are aerobic microorganisms that use similar cyclic hydroxamic acids to scavenge iron. So plants and microbes appear to use the same chelation strategy to obtain their daily ration of iron.

The same process is at work when you clean old coins with Vegemite or cola. The power of chelating agents also explains why the insides of tomato tins need to be lacquered. The citric acid in the tomatoes would dissolve the metal of the container if the lacquer were not present. Household cleaning agents, especially detergents and shampoos, also rely on chelation. These soften water to make it more effective during the cleaning process.

Chelation has its uses in medicine, too. EDTA or ethylenediamine tetraacetic acid is used as a chelating agent to control levels of calcium in the body and can reduce the effects of mercury or lead poisoning.

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Hi Mick,

The molasses needs to ferment before it really starts to work effectively - depending on the temperature this takes a few days and a froth forms on the top. It's a good idea to move the items occasionally to stop masking by bits sitting against each other.

In the fermentation process acetic acid is formed and that is what does the de-rusting. If you have small items - ie nuts and bolts, etc just go to the supermarket and get a bottle of cheap cleaning vinegar - it works the same way and quite quickly!

Hodgo's warning is important - no aluminium, diecast, non-ferrous - they will dissolve. Some cast iron is also affected.

Bob