How To Remove Surface Rust.

Bob Korves said:
Evaporust. Read and follow the instructions. It is safe and works well, but costs more. Acid based de-rusting schemes involve losing some of the original metal along with the rust. If it is a shovel, no big deal. If it is a gage pin, it matters! If it is a Hermann Schmidt grinding vise, it will come out frosted instead of shiny and will be less than perfectly accurate in the tenths world. Of course, the rust removed is also the original metal, so that can matter as well. The gage pins in your photo still have ends that will be completely usable and accurate (the less rusty ends) after Evaporust, but not after vinegar, naval jelly, CRL, and other acid products. Electrolysis done properly is also OK, but it can also cause good metal removal under certain conditions. Molasses, I honestly do not know...
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This the best and most succinct description of rust removal I have seen, particularly pertaining to maintaining dimensional accuracy. +1 on Evaporust.
 
Evaporust uses an acid salt, and the required action is to remove the rust, not the parent metal, any mild acid will do this, including vinegar and cider vinegar. I am not suggesting you leave it in there for a month, I have found that a few hours is all that is neccasary, but if you think that it is better to buy a propriety product, you pay your money and take your choice!
On Evaporust from the schwinbike forum
It is a proprietary formula but many people believe the main ingredient to be the chemical " ethylenediaminetetraacetate or EDTA ".

EDTA: Ethylenediaminetetraacetic acid (or ethylenediaminetetraacetate). A synthetic amino acid (or acid salt) that acts as a chelating agent for many divalent metal ions, particularly lead (Pb+2). A diagram of the acid's molecular structure is shown to the right. EDTA is used medically as an antidote for lead or other heavy metal poisoning in the form of the di-sodium salt, chelated with calcium: Na2Ca–EDTA
 
hermetic said:
Evaporust uses an acid salt, and the required action is to remove the rust, not the parent metal, any mild acid will do this, including vinegar and cider vinegar. I am not suggesting you leave it in there for a month, I have found that a few hours is all that is neccasary, but if you think that it is better to buy a propriety product, you pay your money and take your choice!
On Evaporust from the schwinbike forum
It is a proprietary formula but many people believe the main ingredient to be the chemical " ethylenediaminetetraacetate or EDTA ".

EDTA: Ethylenediaminetetraacetic acid (or ethylenediaminetetraacetate). A synthetic amino acid (or acid salt) that acts as a chelating agent for many divalent metal ions, particularly lead (Pb+2). A diagram of the acid's molecular structure is shown to the right. EDTA is used medically as an antidote for lead or other heavy metal poisoning in the form of the di-sodium salt, chelated with calcium: Na2Ca–EDTA
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As you said, it is a proprietary formula, so we are all just guessing, including Schwinn. All I know is what I see. If you put a piece of steel ground and polished as shiny as a chrome bumper in Evaporust, and leave it for a week, it will be just as shiny when you take it out. If you try that with vinegar, CLR, or other liquids that have acid in them per the label, you will have a heavily frosted finish after a week in them. I have done fairly heavily rusted parallels in Evaporust, and it removes all the rust and leaves a clean, bright finish on the metal that did not have rust. Please do as you please, hermetic, there is room for many opinions here.
http://www.evapo-rust.com/product-info/
 
I ended up getting the evaporust and ended up soaking about 90% of the gage pins in the set I bought. It did a great job of removing the rust, which was heavy in some cases, and didn't seem to affect the size based on the ones I measured. In most cases I had to soak at least 24 hrs to fully remove the rust. The pins did turn a darker color but remained smooth and shiny.
 
sanddan said:
I ended up getting the evaporust and ended up soaking about 90% of the gage pins in the set I bought. It did a great job of removing the rust, which was heavy in some cases, and didn't seem to affect the size based on the ones I measured. In most cases I had to soak at least 24 hrs to fully remove the rust. The pins did turn a darker color but remained smooth and shiny.
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You can get the dark finish off pretty easily with fine Scotchbrite, but I would not recommend that on gage pins... The dark coating is also purported to be a rust inhibitor.
 
Get some sheets of VCI vapor paper from eBay and put them in all your gage pins, gage blocks, and other boxes with precision tools in them. If the boxes close pretty much air tight the VCI paper will keep rust away for a long time. I can't remember exactly, but I think I paid about $8 for 50 sheets, and that lets a lot of worry and effort go away for a small investment, and is easy to do. Make sure you get a grade of VCI for what you are protecting...
 
No problem Bob, I wasn't trying for an argument, we don't seem to have evaporust in the UK, we have Naval Jelly, and various others that seem to be all based on phosphoric acid, but they are quite expensive if you have a lot to do. I used to use one made locally to me (Near Kinston upon Hull) called Kingston Kurust, but it was more a paint that converted the rust than an actual remover. As Neil Young tells us, Rust never sleeps!
Phil
 
hermetic said:
No problem Bob, I wasn't trying for an argument, we don't seem to have evaporust in the UK, we have Naval Jelly, and various others that seem to be all based on phosphoric acid, but they are quite expensive if you have a lot to do. I used to use one made locally to me (Near Kinston upon Hull) called Kingston Kurust, but it was more a paint that converted the rust than an actual remover. As Neil Young tells us, Rust never sleeps!
Phil
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Evapo-Rust has a home page in the UK:
http://www.evapo-rust.co.uk/

Metal Rescue is a new competitor to Evapo-Rust, supposedly equivalent product, here is a UK link:
http://www.metalrescue.co.uk/
 
well it seems they are looking for dealers for evaporust, but metal rescue sell by mail, but it is $57.17 for 5 litres! very expensive! I make my own cider vinegar for free, My workshop is called "Appletree Works"!
 
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