I wanted to share my experience with molasses rust removal. I have sanded, wire brushed, sand blasted, used chemicals and tried electrolysis; but nothing compares to the ease and efficiency of molasses. I did a few trial batches and determined a mix of 1 gallon molasses to 10 gallons of water works best. The real secret to success using molasses in January (in Michigan) is providing a heat source.
My tank’s inside dimension is 60” x 32” x 24” and is easily heated by a used waterbed heater under the pond liner.
My total investment includes $40 in lumber (Home Depot), $39 for a pond liner (Lowes), $29 waterbed heater (eBay) and $52 for molasses (grain elevator).
I placed a group of parts in the mixture January first and removed them today the 7th completely rust free. I did find it best to hang the parts so they are not laying on one another. Areas that were in contact with each other required scrubbing instead of just a quick rinse using a soft bristle brush.
In the first batch I had two doors, two running boards, the door trim, three brake drums and hubs. The hours it would have taken listening to an air compressor running as I would be eating dust and rust cleaning that collection of parts more than paid for my investment. Currently there is a front fender another set of running boards and a few other misc. parts soaking.
Impressive! Thanks for the info.
Guess this works like the sugar beets stuff? How does that compare to this? Thanks, Dan
The molasses I bought is a by-product of sugar beet processing. Bill
Anybody tried this with an engine block? Also where is the molasses purchased. A farm supply store?
Only available from commercial supply houses?
Thanks for the information!
One thing William didn't mention is the smell. Not so much at first but once it starts to ferment . . . whew. Needs to be outside.
That door looks awesome though.
What's a pond liner?
Do you really need the heat?
I tried mol asses a few years ago.
It worked okay cold, I don't remember how long I left the parts in the molasses.
It left all the pained places just as they were.
I had to go to a big store where grocery stores buy their supplies to find molasses in gallons.
If heat is needed I think you could use the heat element for a water heater, just dip it in the tank on a metal or concrete block or bricks.
I've never tried it, but it looks easier than the electrolysis method. I've tried that a couple of times and while some swear it's the greatest thing since cheese grits, I find it cumbersome and still a fair amount of cleaning required after taking it out. This is just giving the parts a good soak and then rinsing. Sounds easy enough. I might try it.
Gotta wonder what it is that does it? I thought 'molasses' was a syrup made from sorghum cane. We make syrup from sugar cane. Wonder will sugar cane syrup do the trick as well? I am not too familiar with sugar beets, but if you can make 'molasses' from sugar beets and sugar from sugar beets and sugar from sugar cane, maybe sugar cane syrup would clean rust like this "molasses"? Then of course there is corn syrup that is readily available at any grocery store. Would that work for folks that don't have a feed and seed store nearby?
I've used molasses with some luck. You do have to have all the paint removed, but the rust will come off. The warmer it is, the better it works. Go to a local feed store and ask for bulk molasses - usually they have it by the 5 gallon bucket, should be less than $10. mike
Pond liner is like roll rubber roofing, which also would work. I used roll rubber roofing in my pond some years back. could not tell the difference, except they charge more for pond liner. Supposedly pond liner is safer for fish than roofing, but I never had an issue.
A pond liner is a reinforced PVC sheet of fabric used to line the bottom of a small yard pond or water fall. When I did my pilot study my garage was at 46 degrees, the lightly rusted parts took a week everything else was closer to a month. I keep the tank covered with a 1/2" thick sheet of styrofoam to help keep the smell and heat in and that seems to work pretty good. You don't want to do this in an attached garage unless you want to give the bride a reason for a divorce. One other piece of advice is use gloves, the smell does not wash off easily. I added a picture of a test piece I did for comparison. Bill
Ok, if it wont remove paint as some have posted what about grease or oil. Do the items need to be degreased such as an engine block?
I removed all the broken bolts and chased the threads before putting the door in the molasses, anywhere the thread cutting oil was on the door required a little extra elbow grease to clean up. Notice the oil stain around the door handle it still did a fair job of removing the rust. There was some oil or grease inside the door that didn't come clean. Bill
Now if we could figure a way to filter the used molasses and sterilize it, someone would figure out how to make Sugar Beet Rum.
See this thread:
I purchase feed grade molasses from Mills Fleet Farm for de-rusting purposes.
Contrary to what you may have read on the internet, molasses will eventually attack the metal.
Eric, if you mean "attack" as in eat all the rust then I whole heartedly agree with you. If you mean "attack" as in damage the metal I want to know where you get this information from? I stripped over half the parts on my 1917 Maxwell and have left some parts in bare metal for several years and have never had it re-rust unless I touch it with wet or sweaty hands. I've heard horror stories about entire frames being eaten completely up and yet I've used the same 1/8 inch wire and sheet metal coffee cans submerged for over 2 years in my tank and it is still as intact as the day I put it in the tank. My experience has been that some metal comes out so clean you can still read the manufacturers etched logos on sheetmetal not damaged by rust, hardly what I would call "attacking" the metal.
It contains a mild Ascorbic acid.
My tank was a 44galon drum. Molasses was mixed at 40% of mixture for best results. Our molasses is a by-product of sugar cane refining, so it may be of different composition.
I too found that paint will not be affected, grease will also stop it working. Steel items cleaned up really well but castings need to be checked. If I left them too long, they became well pitted. It was suggested to me that the molasses attacked the carbon in the castings.
As for the smell, I have smelled much worse odours. My wife is very sensitive to all sorts of chemical smells, particularly lacquer thinners, but has no problems with molasses. Being a farm girl and molasses being an organic product might have something to do with it.
Allan from down under.
I've only done items that I can fit in a large, sealed Rubbermaid container so I have not had problems with the smell.
I've found it best to soak the item for a few days, take it out and clean it with a stiff wire brush and water and then put it back in the mixture. Repeat as necessary. This seems to cut down on the number of days required to soak the item.
Like Allan above said, cast iron can become well pitted. Have not experienced this with forged metal.
I also had a thin spring steel clip from a rare Troy windshield disintegrate when I left it in the solution too long. Not too happy when that happened.
Don't you have trouble with ants unless the container is fully sealed?
I made a mistake and did mine in the summer time, i had to skim the bugs off every day.
I haven't had any insect issue, but than again the outside temperature is 3 degrees tonight. Bill
How long was the parts in the tank ?
John, as other people have answered your question about using molasses to remove rust form your engine block, please be very careful. All Cast Iron and some Spring Steels are quickly etched by this method. This process works best with common steels.
If you use this on Cast remember to watch it very closely as I have found it to be very aggressive on Cast compared to regular Steels.
I destroyed a good head by leaving it in too long.
I tried this method, it works good on sheet metal, but it didn't do anything to a 21 block I put in there and left there for almost 2 weeks
I used beet molasis from a feed store to clean all the body parts on my 26 Fordor project. After soaking for 4-7 days as needed, I power washed then sprayed each part with a rust treatment spray or primer. I found parts would soon surface rust if not treated. One mistake I made was putting a hood in without taking it apart. The hinges froze and I eventually had to find a replacement hood.
I used a 50 gal rubber water trough from the same feed store and covered it with a used piece of panelling. When done with the solution I spread it on the lawn. The iron made for great green grass that year and the smell only lasted a few days!
Dale, I think you could loosen up the frozen hinges on the hood with heat?
Worked fine for me - my hood was stuck by regular rust, not molasses, but it loosened up with heat from the oxy acetylene torch on the hinges.
Steve, The parts were in for six days.
It ruined a valuable engine block for me --Just stripped the carbon out of it to were it had no strength in the casting .Just tightening the head bolts would pull the threads out of the block
Multiple sites discuss the molasses ruining cast iron and spring steel.
as seen on another forum,
"I have used it on all sorts of bits. On body panels I have noticed that the pitting referred to above occurs. As I understand it this is because the acid is not selective. Once it get pasts the rust then it is open slather on the steel or iron below. The pitting is the action of the acid on the carbon in the iron or the steel. That is, it is disolving it. This makes the material brittle. Body panels can end up like they have been through a fire. Brittle and hard to work with.
Other things like rusty engine parts need care too. I had a friend who is into antique motorbikes relate to me how a fellow had retrieved an old crank and flywheel by derusting with molasses. On rebuilding the engine and running the newly completed engine the flywheel disintegrated. Not nice. He and I now both swear by electolysis for rust removal.It is selctive and self regulating . Once the rust has gone then the reaction stops and the plant shuts down.
Basically you have to watch the item you are derusting as you can leave it in too long. Condition and strength of the molasses will dictate the speed at which it acts. Only leave it as long as it needs to get the rust off and protect bare but unrusted metal from contact with the molasses."
Bill, that is sweet!! I'll bring about 9000 parts over this weekend..
A 275 gal tank like for this for $50 with the top cut off and it has a drain valve at the bottom work great and this Molasses for $9.99 a gal from tracker supply works great!!
Bob Trevan, I'd be willing to bet that your blocks threads were gone before you put it in the molasses. I've soaked at least 500 nuts and bolts and all manner of threaded castings an have yet to loose a single one. I've even put completely seized parts and fasteners in and am amazed that when removed them I can usually unscrew them by hand.
I checked last fall at Tractor supply for feed molasses, he told me they don't sell it. He told me to go to the Mennonites general store, and get it, they feed it to their horses. I was told it's $15.00 for a 5 gallon bucket of it. I was told on other sites it doesn't matter if you get liquid, or powder molasses, it works the same.
Howard Dennis is the one who told me all about Molasses rust removal i tried it on some small parts and he was right it works great! These tanks are all over in our area on craig's list. And the local tracker supply has the Molasses that's pictured the last time i checked about 8 weeks ago...
I have a pile of parts waiting their turn to swim in molasses. The tank Robert pictured would be a great way to go. I tried to find a plastic tank to no avail so my best choice was to build a wood box and line it. Bill
Looks great Bill. I wondered what you did with the doors after the soak, wash, and drying. Did you prime right away, or rust bullet, or other?, it seems that they would flash rust quick like a muriatic acid soaking after rinsing..Great idea, can't "beet" a Michigan Sugar product, grown in most of us Michigan folks backyards! Jim Derocher
Well, I bought my liquid molasses today, from the feed store. spring is here, it's been in the 70's, so I guess it's time to do it.
It cost .27 a pound, I only got 60lbs (a strong 5gal jug full) of it to start with, it cost $16.20. Tomorrow I'll mix up a smaller batch to do some smaller parts, while I make a bigger tank to do the larger stuff. I'll then get more molasses.
I have read that people mixed it from 3-1, to 10-1. I am going with 5-1, I hear more people using that mixture, then any other.