misterh
4th Aug 2006, 04:19
If you need to remove rust without damaging (using abrasives) your parts (substrate) and you have more time than money, you might want to have a go at this.
Thoroughly degrease your parts and totally immerse in a mixture of molasses and water.for light rust it may take a day or two, for the really heavy rusted stuff it can take a week or two.
mix ratio: 8 parts water/ 1 part molasses works well although you can make it stronger if you want.
Once its done you have to wash and immediately protect the bare metal as re-oxidation will occur.
Tips. Won't work where paint grease/oil is, The mix will start fermenting after a while so can get a bit rum in there, It's non toxic and biodegradable so OK to chuck it on the grass to dispose of, OK to top up with water if mix starts evaporating,if you have big pieces - find an old chest freezer and use that as a holding tank.
This process works well if your going to salvage original parts and have them plated.
You can skip the next bit unless you want to know the whys and wherefores.
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.
Ben Selinger, Department of Chemistry, Australian National University. Ben Selinger is the author of
Chemistry in the Marketplace and Why the Watermelon will not Ripen in your Armpit (Allen & Unwin)
Thoroughly degrease your parts and totally immerse in a mixture of molasses and water.for light rust it may take a day or two, for the really heavy rusted stuff it can take a week or two.
mix ratio: 8 parts water/ 1 part molasses works well although you can make it stronger if you want.
Once its done you have to wash and immediately protect the bare metal as re-oxidation will occur.
Tips. Won't work where paint grease/oil is, The mix will start fermenting after a while so can get a bit rum in there, It's non toxic and biodegradable so OK to chuck it on the grass to dispose of, OK to top up with water if mix starts evaporating,if you have big pieces - find an old chest freezer and use that as a holding tank.
This process works well if your going to salvage original parts and have them plated.
You can skip the next bit unless you want to know the whys and wherefores.
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.
Ben Selinger, Department of Chemistry, Australian National University. Ben Selinger is the author of
Chemistry in the Marketplace and Why the Watermelon will not Ripen in your Armpit (Allen & Unwin)