Molasses Rust Removal

[Hanno Spoelstra]

Originally Posted by Wayne Hingley

Check this thread, around post #5 and beyond... http://www.mapleleafup.net/forums/sh...590#post210590

And don't forget Rick's Lynx restoration thread: http://www.mapleleafup.net/forums/sh...948#post211948

[Jacques Reed]

Without belaboring this thread I have been a huge fan of molasses rust removal since I heard about it 25 years ago.

Ratio if water to molasses is not critical. I have used 1:1, 2:1 and even 4:1 and it still eats away the rust but perhaps at different speeds.

Always best to remove as much heavy rust as possible before soaking, by wire brush and even a scaling hammer if needs be, as in the case of the rims shown.

In the case of those wheels I took them out after a fortnight, hit them with the Gerni which removed most of the rust and put back in the tank for another week or two for the final clean.

Some myths are around that it eats steel. It does not, but because it is a thorough clean of all the pitting in the steel the misbelief is that it has eaten away some of it.

I had one set of wheels sandblasted and another I did in molasses. The rust removal of all the rust was far superior in the ones done in molasses.

[Alex van de Wetering]

David,

I used a 1:1 mix ratio. I waited about three weeks before taking the parts out; than washed the parts with lots of water. The parts start rusting again in minutes!, so this is something to keep in mind.
There are quite a few video's on the method on youtube, as Jes also pointed out.

In my experience it works excellent for cast parts. I had some trouble with a very thin sheet metal piece....which got partly eaten. However, as Jacques pointed out this is not the molasses eating the steel, but just the molasses removing all the rust...sometimes leaving less material than you anticipated when looking at the rusted part.



I don't know if others have experienced this, but I did my molasses test in Winter.......... at first it worked excellent, but after a few weeks it seemed it lost it's power and crystals also started showing on the surface of the parts. I presume this is bacuse the solution had frozen(?).

Oh....yes, it does smell. BUT..........you can just go to work, and the molasses continues on your restoration while you are away

[lynx42]

Originally Posted by Hanno Spoelstra

And don't forget Rick's Lynx restoration thread: http://www.mapleleafup.net/forums/sh...948#post211948

Thanks Hanno, for the push. I had better get back to writing more on the Lynx restoration. The restoration has been progressing as my health allows so I'll have to find time to continue the saga.

Regards Rick.

[Niels V]

This is very interesting to follow, I have a set of Scammell pioneer overall tracks that I would try dipping in molasses, and then a set of carrier tracks.

[Phil Waterman]

Hi Guys

One comment/question that I would add on molasses, washing soda, electrolysis, cleaning/degreasing of parts, temperature of the fluid.

I've tried most of these different methods for degreasing and rust removal, what I have noted is the temperature plays a big part in how quick and well the process works.

For example washing soda at 180F/82C will degrease and remove paint from small parts just soak the parts for 1/2 hour and then scrub the with a medium stiff brush and the grease and even the OD paint comes off. Yet soak the same parts in same solution overnight at room temperature and nothing happens.

Washing Soda when used for electrolysis doesn't seem to work for rust removal when the solution is much below room temperature. Discovered this, one winter, when I had my plastic tube in the corner of the shop away from the furnace result the tank never got much over 40F/4C rust removal was very slow yet when it was in the direct hot air blast of the furnace progress was much better.

Has anybody else noticed temperature as being a significant factor?

Cheers Phil

[jack neville]

I'm using washing soda and electrolysis with the power supply being a cheap 240/12 volt converter brought off ebay. Wheelie bin is outside. Working a treat but then it is summer in Australia. Strips rust and paint.

[Lynn Eades]

Jack, what amperage is your power supply? there are currently some 240/12v 4 amp ones for sale here for $20 is it good thing?

[jack neville]

Originally Posted by Lynn Eades

Jack, what amperage is your power supply? there are currently some 240/12v 4 amp ones for sale here for $20 is it good thing?

I think it is about 4 amps. Post a photo. Sounds the same.

[Wayne Hingley]

Originally Posted by Phil Waterman

I've tried most of these different methods for degreasing and rust removal, what I have noted is the temperature plays a big part in how quick and well the process works.

Very true Phil. Temperature has a great impact on pH. As the temperature increases, the pH will decrease (ie; the solution becomes a stronger acid). The molecules in the water will also become more active as temperature increases.

It should also be possible to speed up the process by agitating the solution, so that more fresh exchanges occur between the solution and the parts.

[Bob Carriere]

I have used a 45 gallon drum with a lye solution..... afull perimeter stainless steel plate with a 10 amp battery charger and two 12 volts truck batteries....... batteries went flat in a 2 hours and charger overheated......... it was really bubbling and cleaned a suspended cast CMP axles inside and out in 2 hours...... heavy scumof oil and paint on the surface.

Pressure washed and sun dried it looked like new.

Not sure how many amps were going in or how we could measure based on plate size .........

What is it in molasses that does the derusting...... the potassium content??? and if so would not a weak potassium acid bath be cheaper, faster, less sticky and stinky without being lethal to the environment?????

Bob C

[Wayne Hingley]

Originally Posted by Bob Carriere

What is it in molasses that does the derusting...... the potassium content??? and if so would not a weak potassium acid bath be cheaper, faster, less sticky and stinky without being lethal to the environment?????

Bob, I believe molasses has a pH of around 5-6, which means it is acidic. I suspect it is the organic acids that are responsible for the de-rusting process. Since it is a relatively weak acid, it is not too destructive on the parts (as everyone has noted). Thats also why it takes a bit of time to produce results. If you go to a stronger solution, it may be faster but also more damaging to your sensitive parts.

[Jacques Reed]

What is it in molasses that does the derusting...... the potassium content??? and if so would not a weak potassium acid bath be cheaper, faster, less sticky and stinky without being lethal to the environment?????


Hi Bob,

Here is a link to just one of many explanations on how molasses and water works. Not necessarily to be taken as Gospel though. "Chelating" needs to be researched further. It may be safer than other caustic or acetic chemicals used for rust removal but that could just be the authors opinion.
His comments about pot metal, zinc castings, are correct though. Ditto for galvanized parts. It will remove galvanizing.

Environmentally it may be better too. Shipmates on chemical tankers told me that when they carried molasses in bulk they were even allowed to wash the tanks after discharging it and pump the slops into the sea. Apparently the fish loved it. With the strict regime of managing tank washing and recording it I doubt the authorities would allow it if it was extremely hazardous to the environment. It is, after all, a by product of sugar manufacture and we all know how good sugar is for us!


http://www.homercidal.com/molasses/

Cheers

[Tony Wheeler]

Originally Posted by Bob Carriere

What is it in molasses that does the derusting...... the potassium content??? and if so would not a weak potassium acid bath be cheaper, faster, less sticky and stinky without being lethal to the environment?????

Apologies Bob, I've only just stumbled on your question. I've never given much thought to the molasses method but the active agents will be siderophores: "Siderophores (Greek: "iron carrier") are small, high-affinity iron chelating compounds secreted by microorganisms such as bacteria, fungi and grasses. Siderophores are amongst the strongest soluble Fe3+ binding agents known."

One candidate may be Enterobactin: "Enterobactin is a high affinity siderophore that acquires iron for microbial systems. It is primarily found in Gram-negative bacteria, such as Eschericia coli and Salmonella typhimurium."

E. coli may explain the stink you mention Bob. However it's really anybody's guess what you're growing in there. Molasses is rich in nutrients so you're basically creating a giant petri dish. It will be colonized by all manner of airborne microorganisms, particularly in Spring and the warmer months when they're most prevalent. Plus of course whatever animal droppings happen to get in.

On the question of alternatives the ideal compound would be EDTA. It's a widely used synthetic chelating agent which I know about only in theory, but which I'm quite certain would be far superior to molasses method. The only question would be cost and availability in bulk, as it appears to be produced exclusively in China with minimum order quote in metric tons! However my search for "industrial grade EDTA" returned lots of these which you may be able to source locally:

EDTA.jpg


Meanwhile I found some on ebay which looks ideal for trialling:

http://www.ebay.com.au/itm/EDTA-4Na-...UAAOSwZd1VW2YO