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Rust Removal using Molasses

widlin1

Aluminum
Joined
Sep 13, 2003
Location
Bel Air, MD
I don’t how many of you know about using molasses and water to remove rust, but it works real well. A few years back I bought this stuff called Evapo-Rust to clean up a Sheldon shaper I had just bought. The add said it contained chelating agents that removed the iron from the oxide but not from metallic iron and that it had a sulfur compound in it that then precipitates out the iron. It worked very well but cost with shipping close to 20 dollars a gallon. So in looking on the internet to try and ID the chelating agent I found that molasses contains chelators for iron and does the same thing. I bought 5 gallons of non-de-sulfurized (still has the sulfur in it)molasses at a feed store for 12 cents a pound and diluted with between 7 and 10 parts well water. I washed a bunch of rusty parts from a IH bus and a chisel that had been barried when the house was built in ’56 in laundry detergent and hot water to remove grease and oil and dumped them into the molasses bath. After a day you could see some result but after 2 weeks it was remarkable the amount of rust that was gone and my basement smells good too. It is one of those things that seams like it is taking along time the first week but as soon as you get involved in other things the time goes by real fast. Below are are some pictures. The vice was allowed to soak over night before taking the second picture it has now been in the tube for two days. I am now looking for a bigger tube so I can soak some fenders and my 9x20 wheels, and also thinking about adding some deturgent to the mix to see if it helps with greasy parts.

Forgot one other thing I found out about the power of Molasses it is used to remediate chromium V in well water. It is pumped into the water and reducies the chromium V to chromium III.

Jeff

DoubleBubleToiletTroubleSM.jpg


Chisel2WeeksSM.jpg


BatteryBoxdrippingwetsm.jpg


ViseBeforeSM.jpg


Viceafter19hourssoaking.jpg
 
I can see where that would be kind of handy as a method -- the solution I'm assuming is very benign and non-toxic, no wires or power supply to deal with. Patience is the only additional required additive. Finally, a multi-purpose air freshener!!

Have you tried it out on pot metal? I know that other rust removal tehniques (namely the electrolysis and muriatic acid) routes tend to dissolve anything other than steel.

My current favorite routine is muriatic acid, followed by electrolysis for fast, effective rust removal on steel(unless the part is quite large, in which case electrolysis all the way). I used to use muriatic acid only, until someone was kind enough to point out that the reason my parts would re-rust so quickly unless painted or oiled IMMEDIATELY, was due to the chloride ions remaining from the HCl (kind of like putting my parts out in salt water after de-rusting). Electrolysis solves that problem.

Chad
 
Hello,
Looks like a good idea. Is there any special storage requirments for a bucket of this stuff after its mixed up? Or is it cheap enough to just dump it after you use it? How do you mix it? I know how much, but molasses isn't as easy to mix with water as say something like sugar.

Thanks
Richard
 
I just dumped in the liquid mollasses and added water and stirred. The molasses desolved right away. The soution is environmentally friendly so you can pour it down the drain or dump it in the yard. I think it is probably fine on aluminum and pot metal but have not tried it. I think for tools it is better than muriatic acid becuase it does not desolve the base metal like the acid does.

Jeff
 
I just dumped in the liquid mollasses and added water and stirred. The molasses desolved right away. The soution is environmentally friendly so you can pour it down the drain or dump it in the yard. I think it is probably fine on aluminum and pot metal but have not tried it. I think for tools it is better than muriatic acid becuase it does not desolve the base metal like the acid does.

Jeff
 
I think the citric acid in evaporust is in there to help degrease the metal so that chelators can get at the iron oxide. I agree evapo-rust works very well, but it is expensive, and my experience with evapo rust is that heavy rust takes longer than a couple of days to clean up, unless you brush it down every day to remove the loose rust and black iron sulfide.

Jeff
 
I just did some searching on citric acid as a rust remover and it looks like neutralizing the acid with amonia is supposed make a good rust remover. It has three carboxyl groups and a hydroxide that I could see chelating iron. Maybe a citric acid bath is a project for another weekend. One pluss of the molasses is that it is a much weaker acid than the carboxilic acids.
 
TEA works great. I dont know why more people arent using it. VERY CHEAP. Just make as many gallons as you need (brew or just let it soak). Then soak your parts 4-8 hours, wipe off & apply your favorite rust protectant.
 
Rust reomval:

Oxalic acid is avaiable at most hardware stores. It is cheap and will remove rust in much less time 12-24 hours. If you are in a hurry 1 part nitric acid (18 molar wt) and two parts sulfuric acid (12 molar wt) and a quick bath in distilled water also works. From the chemistry hand book. It also will literally take the skin off your bones. If you are in only a 24 hour hury you can use Coke-cola.
Rustystud
 
With all due respect, I don't call what Coca Cola does to metal "rust removal", it just turns things black and makes the rust look different. With Molasses we're talking making a rusty engine block look like a brand new casting, like a brand new water pump or master cyl. you'd buy at the parts store. I'll see if I can find my pics.
 
The three big advantages of molasses are it is much cheaper than the other methods (6 dollars of feed grade molasses makes 50 gallons of solution, I think that volume of evapo rust would be 400 to 500 dollars) and the chelators do not oxidize metallic iron so they only remove rust and do not affect the base metal which any of the methods that use muriatic acid (HCL), nitric acid, phosphoric acid (including coke and navel jelly), or oxalic (I think) will do. You can soak a scraped surface in molasses and when you are done the rust is gone and the scraping marks that were not rusted are still there. Lastly the end products are environmentally friendly.
 
Sounds like it would be good for motorcycle gas tanks! The choices are limited when coming in contact with the painted outside. Thanks for the info, I am going to give it a try. Who cares if it takes a little longer but doesn't harm the paint!
~dale
 
Great news on the cheapness and effectiveness of molasses. Ditto on tea. On citric acid, I've occasionally mixed Real Lemon from the grocery store 50-50 with water. Degreased machine tool parts can be derusted in about 4 hours in the summer. Expensive, but very effective. I rinse, blow air dry, and use a rust penetrant oil to keep the rust away when sitting on the shelf. I've also tried vinegar, but buying strong enough is the challenge. Gnats seem to like to fly around the vinegar, but seem to leave the Real Lemon mixture alone. I've stopped using Real Lemon and vinegar because of expense and because I can now sandblast most items. I may try the molasses for the fun of it.
 








 
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