Rust Removal

[Rob Sack]

I picked up some tools from an antiques shop. They have surface rust but no pitting. What is the best way to remove the rust without damaging the underlying metal? I have tried a stiff wire brush wheel in a drill press with little success.

[Pat Germain]

In the automotive restoration world, a lot of people swear by Evaporust. Might be worth a try.

[mike stenson]

Assuming these are hand tools, there are a variety of methods. I've used citric acid (or vinegar) in the past, that works, but leaves a dull surface. Evaporust leaves a similar surface IMO. Electrolysis is probably the best method. All in all though for flat surfaces I use a razor blade scraper and a lubricant. Scrubbing with Barkeepers Friend and a scotchbrite also works.

[Cameron Wood]

I have good results with a wire wheel, but better in a bench grinder, which spins much faster.

[Jim Becker]

I used the Boeshield product awhile back when I had rust from condensation in the temporary gara-shop. Needs good ventilation as it's a very mild acid, but it works well. Someone recently mentioned using white vinegar, but I have not tried that nor do I know if it's viable or effective

[Jimmy Harris]

Lots of options. It kind of depends on what it is and how much rust it has, as to which method is best.

If it's flat, like a hand saw blade, I prefer wet sanding with some light oil like WD-40 or whatever's cheap. The advantage to this method is it polishes and removed rust at the same time, so you don't get dull looking metal. It's also easier to control if you're trying to preserver something like an etching. And if you're willing to go through a lot of grits of sandpaper, you can give it a mirror finish is you desire. The downside is it's a LOT of labor. But it usually takes less time. Just a whole lot more effort.

If it's more complicated with nooks and crannies, I prefer vinegar (acetic acid), citric acid, absorbic acid (dark soda), or pretty much any other mild acid. First, disassemble the tool and separate the rusty bits from the good bits. Depending the strength of the acid and the amount of rust, you'll want to let it soak from anywhere between 1 to 24 hours. Then scrub off what's left by hand. Just be sure to wash it in soap and water before hand, to remove any oil and grime that might interfere with the acid, and wash it good in soap and water or an alkaline water (like water and baking soda or washing soda) to neutralize the acid. That's the stage I usually use a brush to knock off the remaining rust. Acid, if left on iron or steel and exposed to air will flash rust pretty quickly, so you want to get it off quickly when your done with the soak. Then, coat it in a light oil or wax, as it will have lost its natural corrosion resistance for a while. The downside, as noted, is that it dulls the look of metal. It does this because it literally eats metal. In fact all of the methods listed work by removing metal, both good and rusted. It just eats the rust quicker than it eats the good metal. Kind of the same thing with Evaporust, only Evaporust is reusable and doesn't leave as much black staining behind. But you can often polish it back to shiny if you want. The longer it soaks, the more metal it'll eat and the duller it will get, so try not to let it soak any longer than it has to.


Lastly you can try electrolysis. It's a bit more complicated of a setup and can still leave the metal looking dull. I've never tried it for steel or iron, but I've done it for silver, copper and brass. Personally, I'd rather go the acid route as it's basically the same thing only cheaper and easier. But it doesn't make the metal look as dull as the acid methods.

[Bill Dufour]

EDTA in water is poor mans evaporust. Will not harm paint, aluminum or metal. will not remove good metal. Safe enough to eat.
Electrolysis can cause hydrogen embrittlement of hard steels. It can dissolve all the metal if left for too long. Will destroy aluminum and pot metal.
Bill D.

[Curt Harms]

I used the Boeshield product awhile back when I had rust from condensation in the temporary gara-shop. Needs good ventilation as it's a very mild acid, but it works well. Someone recently mentioned using white vinegar, but I have not tried that nor do I know if it's viable or effective

I believe Naval Jelly, if it's still around uses phosphoric acid so another mild acid. If memory serves phosphoric acid converts one form of iron oxide (rust) to another form which is chemically stable, it doesn't continue to rust. Not polished though.

[Randall J Cox]

I have used white vinegar many times successfully and it's cheap. Leave in for 24 hours brush off while still in then hose off and dry before it starts to rust again. At this point I normally paint whatever I derusted. Randy

[Mike Wilkins]

Fine Woodworking magazine had an article a few years back on removing rust from tools. All items mentioned above were covered, but the most interesting rust removal method involved placing the tool in a plastic bucket filled with Coca Cola/Coke. I believe the phosphoric acid in the drink was the catalyst. May have to leave it in soak for a few days.
That's one reason I don't drink soft drinks anymore. Except in Jack and Coke.

[Richard Coers]

If it's just surface rust, what's wrong with Scotch-Brite pads? Your wire brush can destroy a good hand tool by rounding over edges and actually digging into grey iron.

[glenn bradley]

Evaporust is inexpensive, widely available and somewhat reusable. I have been using a gallon for many years. It does leave things with a dark tint that can be polished off if desired. If the tools are users I just use them right after rinsing/drying.

[Jim McCue]

In the past I used evaporust, which works but did make the metal dull looking. You have to completely submerge the tool also, can't leave a section sticking out. You can keep reusing it though. I disposed of mine when I moved and not sure I will buy more. I wouldn't say it's cheap, last I looked it was $29 a gallon, sometimes I used more than a gallon.

For my next tool I think I will try oil and scraping/abrasives.

[Norman Pirollo]

If it is light rust, you can use a Rust Eraser. Sold through woodworking retailers, Lee Valley in Fine or Medium. It also polishes the metal somewhat. I have had success with this on metals which aren't already pitted with rust.

Norman