Thread: Molasses Bath Trick

Originally Posted by p38arover

So the stuff I've been using for 25 years doesn't work?

All I am saying is straight molasses does not remove rust, molasses with something else in it might. I have three huge mild steel tanks I use for molasses and inside they are big time rusty, thick flakes. Fortunately they are very thick tanks so hopefully it will take years for them to rust out. If molasses had any effect on rust at all when I get it delivered and the guy over filled the tanks and it spilled all over the sides of the tank the tank would be shiny, so would my troughs.
Chris

I had a quick google and it seems a lot of people have removed rust with molasses, but it for sure did not work for me at all. I am away for a couple of weeks at a shooting comp (I am leaving very soon) so I cant do it now but I am happy to try an experiment again when I get back. My straight molasses and a bucket of molasses a a rusty item for a couple of weeks.
Chris

Your problem may be the straight molasses.

I have never seen a recipe for using straight molasses the highest concentration was 4:1 and it may be the solvent nature of water that activates the molasses. The soup certainly gets bubbling with high concentration molasses soup relatively soon after a rusty metal item gets dipped.

Using a caustic or acid bath does work faster but also eats the good metal.

Molases eats white metals: lead, zinc, aluminium.

A new word for the vocabulary......chelation

Rust removal by chelation

Molasses works fine for me and I've also used vinegar. Just about to try electrolytic removal.
I usually use phosphoric acid as soon as I dry the part to stop rusting (available in Supercheap, Bunnings etc.).

Why does molasses remove rust

No mention of urea......


Colin

My dad has been using diluted molasses for cleaning vintage car parts for over 40 years so i know it does work, there is nothing special about the molasses they he sources from a local feed stock supplier.

Originally Posted by gromit

A new word for the vocabulary......chelation

Rust removal by chelation

Molasses works fine for me and I've also used vinegar. Just about to try electrolytic removal.
I usually use phosphoric acid as soon as I dry the part to stop rusting (available in Supercheap, Bunnings etc.).

Why does molasses remove rust

No mention of urea......


Colin

I am aware what chelation is, actually despite owning a farm I am a biologist so studied a bit of all the sciences at uni.We did try mixing with water though and got no sucess at all even after a week, this was after a week in undiluted. I am willing to try again when I get home, but last time it made not the slightest difference to the rust.
Chris

Originally Posted by gromit

A new word for the vocabulary......chelation

Rust removal by chelation

Colin

Wow, new word for the vocab indeed, but I can't get over how bad the author's spelling is! -10 credibility points.

But you well and truly made up for it with the second link. Reminds me how much inorganic chemistry I forgot. It does make specific mention of molasses derived from sugar beets (mainly for animal feed) and sugar cane derived molasses. The difference being the sucrose content of each, with sugar beet molasses having virtually no glucose content, which seems (by this article at least) to be the main driver for Iron 3 to Iron 2 reduction.

Without researching all the stuff I've forgotten in the past, seems like we might have a clue as to why Mr Latte's molasses sucked.

Ok so basically if it is sugar cane based it is useless, if it is from beet it will work..
I am not going nuts then. I had to study a lot of chemistry but I was happy to eject as much as possible from my brain 10 mins after the exam
I will be happy to do an experiment when I get home, but as I said it did nothing to rust before, actually I am happy to have a reason why..
Chris