After reading the recent posting on this I decided to do a couple of tests. I bought a pint of "blackstrap molases" in the grocery store for about $3.00, mixed it with 5 pints of water in a plastic bucket and put in a aluminum piston with rusted in wrist pin and piston rings and a bunch of rusted T rod caps with babbit on them. Heeding the cations about fruit flies etc. I placed the bucket in a large clear plastic garbage bag and tied it shut. After about 4 days most of the rust was removed. After 7 it was all gone but a black residue is left and maybe some loose rust. This can all be washed off with a gargen hose but a pressure washer would work better. If it was particularily rust than the black residue is slightly harder but can be rubbed off with your hand. The big plus is there was no apparent damage to the aluminum piston or the babbit bearing. It did remove some bad oxidation on the crown of the aluminum piston. It seems that the surface of the steel/cast is quite active after cleaning so I spray it with WD40 which works as a good drying agent and provides some modest rust protection. The advantage over oil is that it "dries" and is not sticky and does not attract dirt. It is not real durable rust protection though.

Electrolysis will do that also, and not collect fruit flies..................
Bob

Electrolysis rust removal of parts made from mixed metals will probably cause major damage to the parts due to electrolysis between the different metals. It may also affect the rust removal.

A while back I asked an aquaintance who was chief conservator on the Moniter project about molases rust removal. He hadn't heard of it but guessed the rust was removed by some by-products from the bacteria breaking down the sugar in the molases.

The Mole family home was near the farm house. One Saturday morning, Papa Mole stuck his head out of the hole and said, "I smell pancakes!"
Mama mole stuck her head out and said, "And I smell maple syrup! MMmm!"
Poor baby mole was stuck down in the den, and all he could say was, "I smell Mole-asses!"
The mole hole was under the abandoned Model T (required T content).
T'
David D.

Read this:

http://www.newscientist.com/article/mg17123088.100.html

As stated in a post in a prior thread, I did a test with molasses on a heavily and deeply rusted item with excellent results (a spring clamp from a Model T front end that had been sitting in a grove for 50 to 60 years). I did not buy expensive stuff from the grocery store - I bought it cheaply at the local farm and fleet (type that is used with livestock).

People may laugh at the practice of using molasses to remove rust. However, it does work and the real beauty of using the process is that it is mild and you don't need to "tend to it." You simply put the item in a container and walk away while it soaks. It does take one to three weeks depending on the mixture and the severity of rust but to me that is a non-issue.

Unlike Les Schubert's post above, the mixture completely removed all the rust on my item after a rinse under the tap (three week soak with a 5:1 water to molasses mixture). It left the surface dull/matted but after a quick and easy once over on the wire wheel, it was shiny bright like chrome.

Regarding fruit flies and smell: I used a quart glass jar with lid and set it on my basement workbench. No smell, no fruit flies. For larger items, I would think sealable Rubbermaid container/box would work (I'm not talking about engine blocks or fenders - that would be a different story.)

Regarding electrolysis - I have never tried it but an acquaintance that does it on a regular basis told me that for cast iron items, after the rust is removed you should heat the item in an oven or let it sit out in the sun. Apparently, during the process the iron will be brittle if this is not done.

Erik Johnson
Minneapolis, MN

Hi there blokes,

We have been using molasaes for years and found it to be really good. Stockfeed type molasses is fine, though we did a bench test of different concentrations to find out which was most effective.

Using a 200litre plastic drum with a loose fitting lid, we usually hang the items in a solution of 40% molasses to water. Getting organised would see you fit a loop of air line in the bottom with a few holes in it. It seems to help the process if you stir the stuff up using compressed air at least once a week. I didn't try an aquarium bubbler though.

The only energy this process uses is the afore mentioned stirring it up, unless perhaps in your colder climates it might want an aquarium heater?
Just dont break the glass with your parts!

I can't remember off the top of my head how other metals go, they cartainly don't get eaten like electrolosis can. It does seem to clean different iron alloys at different rates. From expeience it seems that it likes Henry's forged components more than cast iron.

A pressure cleaner is a good idea for cleaning residue, though a garden hose and a stiff nylon brush will suffice without the noise. Ideally you need an industrial parts washer (dishwasher) or steam cleaner. If the parts are hot washed then they're much easier to dry. Either way, as in any cleaning process, flash rusting will occur if you don't preserve them immediately.

It's a very good mehod of cleaning though. Quiet, energy efficient in the extreme and I don't think the leftovers are toxic either. Just takes a little time, but when you have a rusted solid transmission to save there isn't a better way

An old farm boy from wisconsin told me that
putting rusted parts in the WHEY BARREL works
good for rust remove
Bill