rust removal

with all this soaking and dunking in stuff molasses ect how does one stop the process once it has started eg in the folds of the tin of the thing getting soaked because how would you no when all the molasses has been removed could it start the process every time it gets wet ???????? I can see how it works ok for a hinge or step were there is no fold in the metal but other things like the step off a D 5 N dodge or inter there is plenty of spots that cant be got to when cleaning seeya
Paul

Won't matter, Mrs Mac. Once the rust is eaten out, the molasses stops working. A high pressure water blast in the join will get rid of it. If there's any molasses left in the gap, you'll be left with a bonus sweet smell in the fold! :

There's a bloke over here who uses bread and water to clean up rusty parts. Just get some stale loaves of bread and a tub of water, put your bits in and leave for a while.

I don't know the bread to water ratio, or what reaction makes it work, but do it well down the paddock because the smell is horrible. Cheers

There's a bloke over here who uses bread and water to clean up rusty parts. Just get some stale loaves of bread and a tub of water, put your bits in and leave for a while.

I don't know the bread to water ratio, or what reaction makes it work, but do it well down the paddock because the smell is horrible. Cheers

Bread (& molasses) both work due to the fermentation of the mixture.
Basically, removing rust using molasses (or bread) uses a process known as "Chelation" & can best be described as "Reverse Oxidation", wherein certain bacteria formed by the fermentation process of the solution strips the oxygen from the rust molecule of iron oxide (rust).
Molasses is a carbohydrate by-product of sugar cane refining & contains some plant proteins. The amino acids which constitute proteins include cysteine & methionine which importantly contain SULPHUR, & sulphur bonds are what give proteins elasticity (which is why skin is elastic), hence the elasticity of bread dough once yeast is added to make the dough rise... (see where the bread comes in now?).
As the molasses (or bread) ferments in the water, it creates harmless aerobic bacteria, which derive their food source from the mixture & get their oxygen from the iron oxide (rust).
The bacteria remove the rust by robbing the oxygen from iron oxide, because they need oxygen for their utilization of nutrients from the molasses so they can reproduce & proliferate.
Therefore (theoretically), anything that is plant based & ferments should be able to achieve the same result.
You should always use animal feed (sulphated) molasses, not human grade (sulphate removed) molasses for this task & the parts must be degreased completely, since the solution will not cut grease, & the grease will prevent the solution from contacting the rust.
Temperature is also important to the little bacteria, because too cold & they're not as active, too hot & they could die. EXTREMELY hot & they start turning into alcohol & ethanol...

Glenn...

Thanks for the explanation hypermung.

Some of you on the forum will remember Professor Julius Sumner-Miller who had the TV science program "Why is it so?" which later became "Why it is so"

Looks like we have our own forum guru Professor.

Cheers Geoff

Once the job is dome spray with phosphoric acid which 'converts' any rust left and creates a protective layer. Some paints contain phosphoric acid as an anti rust additive.

Just to keep this hijacked thread updated with my molasses rust removal : here's how the Fordson wheels went. Check reply numbers 14, 20 and 33 ...

www.hcvc.com.au/forum/YaBB.pl?num=1388930384/0