Molasses

[Mike Hutchison]

So I'm just idly searching planes on eBay and in the descriptive
part of a listing for a Stanley 113 the seller suggests a bath in
"molasses and water mix" for rust removal without damage to the japanning. May be valid tip but must admit new to me, especially the water part. Ever heard of this?

[John Coloccia]

Molasses has some acid content. It's just one of those home grown solutions people like to use to show they're clever, though they're not really clever because only about 1 in 100 actually know why it works...LOL. Evaporust works well. I don't think I've ever heard that it has harmed japaning.

[Jim Ritter]

Apparently I'd does work. I've not tried it. Don't know why it works. There was a long discussion about it on another forum a while back.

[Michael Ray Smith]

Evaporust works well.
Yes, it does, and without acid, which not only attacks the rust but can also attack the underlying metal. It works on a different chemical mechanism. If it just weren't so expensive!

[Jim Koepke]

It's just one of those home grown solutions people like to use to show they're clever, though they're not really clever because only about 1 in 100 actually know why it works...LOL.


This makes me think of people when it comes to splicing rope. Everyone seems to know that a short splice is stronger and more reliable than a long splice. It may not even be 1 in 1000 who know they are two different ways of splicing rope that are used for different reasons.

It is always some clever person to mention this factoid. It always seems the clever person also has no idea of how to splice rope or even tie a decent knot.

jtk

[Bill White]

I'd use it, but I just can't get the moles to sit still long enough. They're too busy sittin' on my biscuits (not joiner, but that's next).
Never heard of that, but who's to know?
Bill

[ray hampton]

I refuse to waste molasses on rust removing , will tomatoes or vinegar remove rust ?

[David Keller NC]

Yes, it does, and without acid, which not only attacks the rust but can also attack the underlying metal. It works on a different chemical mechanism. If it just weren't so expensive!

If you choose, you can get the same chemical mechanism from citric acid (chelation). The neat trick with evaporust is that contains not only a chelator, but a sequestering agent. The chelator removes the iron oxide from the steel surface, and the sequestering agent removes the iron from the chelator, thus recycling it. The solution only gets "used up" when both the sequestering agent and the chelator are completely bound with iron from the iron oxide.

Citric acid is also a chelator, and it's a whole lot cheaper than evaporust. And it will not attack iron in its native (unoxidized) state. You can get it at home brewery supply stores, where it is used to clean stainless wort tanks.

[ray hampton]

citric acid, do the drink mix "Tang " contain citric acid ?

[David Keller NC]

citric acid, do the drink mix "Tang " contain citric acid ?

Yes, as does orange juice. The catch is that the concentration may be so low that it will take longer than you want to remove the rust, and Tang and orange juice are opaque (or at best, translucent), so you can't see the reaction without taking the tool out of the solution.

[Dustin Keys]

If you choose, you can get the same chemical mechanism from citric acid (chelation). The neat trick with evaporust is that contains not only a chelator, but a sequestering agent. The chelator removes the iron oxide from the steel surface, and the sequestering agent removes the iron from the chelator, thus recycling it. The solution only gets "used up" when both the sequestering agent and the chelator are completely bound with iron from the iron oxide.

Citric acid is also a chelator, and it's a whole lot cheaper than evaporust. And it will not attack iron in its native (unoxidized) state. You can get it at home brewery supply stores, where it is used to clean stainless wort tanks.

I like EvapoRust, but for me it has been replaced by citric acid. CA is much more cost effective and does effectively the same job. You can get it from Amazon pretty affordably. I did a huge (for me) batch of old tools a few months ago including large machinist's files, full size saw plates, large planes, etc. It takes lots of money to use ER for that kind of stuff and you'll be rigging up weird arrangements to try to stretch the fluid as far as you can to cover the large tools (I would rig up plastic trash bags propped up close to the shape of the object to use as little ER as possible). CA is so cheap and easy to work with that you can just fill a long shallow tupperware container with it and throw the tools in there. Much easier and cheaper than ER for the same job. It worked just as well for me and I still have tons of it left for other jobs.

I wouldn't bother with molasses considering how well the alternatives work.

D

[Michael Ray Smith]

If you choose, you can get the same chemical mechanism from citric acid (chelation). The neat trick with evaporust is that contains not only a chelator, but a sequestering agent. The chelator removes the iron oxide from the steel surface, and the sequestering agent removes the iron from the chelator, thus recycling it. The solution only gets "used up" when both the sequestering agent and the chelator are completely bound with iron from the iron oxide.

Citric acid is also a chelator, and it's a whole lot cheaper than evaporust. And it will not attack iron in its native (unoxidized) state. You can get it at home brewery supply stores, where it is used to clean stainless wort tanks.

Yes, I've also used citric acid, and everytime I hand over my credit card to pay for Evaporust I tell myself I should go back to it. It's the "acid" part of citric acid that makes me nervous, and I haven't found anything that Evaporust has damaged (including japanning, by the way), except that it will remove at least some types of paint, and that's sometimes a bonus. With your comments, maybe I should give citric acid another chance.

[Dustin Keys]

Yes, I've also used citric acid, and everytime I hand over my credit card to pay for Evaporust I tell myself I should go back to it. It's the "acid" part of citric acid that makes me nervous, and I haven't found anything that Evaporust has damaged (including japanning, by the way), except that it will remove at least some types of paint, and that's sometimes a bonus. With your comments, maybe I should give citric acid another chance.

That made me nervous too, but I couldn't justify the cost for Evaporust for some of the larger stuff I needed to do. The citric acid left me with a finished product just like the Evaporust. It didn't harm the japanning. One thing I did notice is that it seemed easier to get the gray residue of the citric acid off of the finished product than the gray residue of the evaporust. Aside from that small difference (which could have been just my imagination), they performed identically.

D

[Roy Griggs]

Most Chemical supply houses (one of the locals here is Brainard Chemical Co. in the Yellow pages under Chemicals) have citric acid in bulk quantities. It took me two calls to find someone who had the citric acid! I buy 8 pounds tubs for $24 which makes about 16 to 32 gallons of solution or about $0.75 to $1.50 a gallon. Nothing I've used can compare on cost except electrolosis and I've never been able to get the electric cost figured out!

[David Keller NC]

It's the "acid" part of citric acid that makes me nervous, and I haven't found anything that Evaporust has damaged (including japanning, by the way), except that it will remove at least some types of paint, and that's sometimes a bonus. With your comments, maybe I should give citric acid another chance.

Michael - So here's the chemistry part of this. While we call any molecule that has an ionizable proton group an "acid", there are differences between the mineral acids (hydrochloric, sulfuric, nitric, etc...) and organic acids like citric and acetic. The chemistry definition between these two groups are "strong acids" and "weak acids". The strong acids are completely ionized in aqueous (water) solution; the weak acids are incompletely ionized.

In practical terms, the strong acids will attack any metal in its native state except gold and platinum. The weak acids will attack certain alkali metals like sodium and potassium, and certain transition metals like zinc. But in general, they won't attack metals like iron, nickel and chromium. That doesn't mean that it would be a good idea to plunge one's pristine but dirty nickel-plated Stanley dovetail plane in a citric or acetic (vinegar) acid bath, but old rusty iron and steel tools are safe.

One interesting property of citric acid is that it's very, very effective at removing that ugly galvanic coating off of plated screws and inexpensive "outdoor" hardware. Galvanic coatings are generally zinc-based, and the citric acid will attack it to form zinc citrate.

Finally, citric acid is extremely safe in contact with skin, and won't harm plumbing in older homes. It is also environmentally friendly - bacteria in the sewage system will break citric acid down into carbon dioxide and water. The only caution I would add to disposal of used citric acid solutions is that one shouldn't pour a large amount of concentrated citric acid down the drain if your sewage disposal system is a septic tank. The large pH swing that might occur in the tank might mess up the bacterial colonies that break down the waste. Instead, I would neutralize the citric acid with baking soda - just add small amounts to the citric solution until it stops foaming (do this outside - the reaction between the citric acid and baking soda has the potential to make a real mess!). The gas that is evolved from this reaction is carbon dioxide, by the way, so it's safe.

[Michael Ray Smith]

Michael - So here's the chemistry part of this. While we call any molecule that has an ionizable proton group an "acid", there are differences between the mineral acids (hydrochloric, sulfuric, nitric, etc...) and organic acids like citric and acetic. The chemistry definition between these two groups are "strong acids" and "weak acids". The strong acids are completely ionized in aqueous (water) solution; the weak acids are incompletely ionized.

In practical terms, the strong acids will attack any metal in its native state except gold and platinum. The weak acids will attack certain alkali metals like sodium and potassium, and certain transition metals like zinc. But in general, they won't attack metals like iron, nickel and chromium. That doesn't mean that it would be a good idea to plunge one's pristine but dirty nickel-plated Stanley dovetail plane in a citric or acetic (vinegar) acid bath, but old rusty iron and steel tools are safe.

One interesting property of citric acid is that it's very, very effective at removing that ugly galvanic coating off of plated screws and inexpensive "outdoor" hardware. Galvanic coatings are generally zinc-based, and the citric acid will attack it to form zinc citrate.

Finally, citric acid is extremely safe in contact with skin, and won't harm plumbing in older homes. It is also environmentally friendly - bacteria in the sewage system will break citric acid down into carbon dioxide and water. The only caution I would add to disposal of used citric acid solutions is that one shouldn't pour a large amount of concentrated citric acid down the drain if your sewage disposal system is a septic tank. The large pH swing that might occur in the tank might mess up the bacterial colonies that break down the waste. Instead, I would neutralize the citric acid with baking soda - just add small amounts to the citric solution until it stops foaming (do this outside - the reaction between the citric acid and baking soda has the potential to make a real mess!). The gas that is evolved from this reaction is carbon dioxide, by the way, so it's safe.

Yes, I'm familiar with strong and weak acids. What has made me nervous is that I generally don't know exactly what metal or alloy I'm dealing with, and some corrosion charts show that citric acid is incompatible with some metals. For example, this one, http://www.engineeringtoolbox.com/metal-corrosion-resistance-d_491.html shows that citric acid is incompatible with cast iron. I assume the problem is pitting, and the localized pH inside a developing pit can be much, much lower than the pH in the bulk solution.

However, I can't say that I had any corrosion problems (pitting or otherwise) the few times I've tried citric acid, and you've persuaded me to give it another shot. So it's off Amazon.com I go to order a 5-lb bag ($19.53 with free shipping). Nonetheless, it won't get anywhere near my brand new LV low angle jack plane (made of ductile cast iron) that just arrived yesterday, but with the corrosion inhibitors LV uses and the tender, loving care I plan to give it, it will not need a rust remover until long after I've gone to that great woodworking shop in the sky.