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AR5100 Rust Remover

Highly Concentrated Industrial Grade Rust and Oxidation Remover

AR5100 Rust Remover
AR5100 Rust Remover

AR5100 is an industrial grade pH neutral (not acidic) rust and oxidation remover that quickly and effectively removes even the heaviest corrosion from metals.

AR5100 is highly concentrated and must be mixed with 15 parts of water to activate.


  • Works on ferrous and non-ferrous metals
  • Brightens copper and other copper based alloys
  • Fast-acting (Results in as little as 15 minutes)
  • Non-flammable and non-toxic
  • Re-use many times before chemistry depletes


Removes even the heaviest corrosion from metals

Use AR5100 to remove rust from auto parts, tools and more. AR5100 is a great product to use to restore corroded fuel tanks and radiators, for example.

Use on steel, iron, brass, copper, chrome and other metals and alloys

AR5100 removes rust from a large number of surfaces while leaving most other materials - (plastic, rubber, paint etc.) unharmed.


Step 1: Mix 1 part of AR5100 with 15 parts water. You can add 8 oz of AR5100 concentrate to a 1 gallon container and fill the rest with water to create a 15:1 solution. Use hot water (120F+) to decrease the amount of time needed to remove oxidation. You must mix AR5100 with water to activate the chemistry. Mixing AR5100 with less than 15 parts water will not make it more effective.

Step 2: Immerse item in AR5100 solution until all oxidation is removed. You may also add AR5100 to pressure washers. The solution will change color as it removes rust from the item, this does not mean the solution is spent, you can reuse the AR5100 solution many times until it is no longer effective.

IMPORTANT: AR5100 will leave behind a dark patina on some metals, this surface is not rust and is ready to prepare for painting or welding.


AR5100 gets to work in as little as 30 minutes

AR5100 works very quickly, upon exposure you will very quickly see oxidation falling off the surface of the rusted item.

Removes rust instead of converting it

AR5100 is not a rust converter, AR5100 completely removes all rust from corroded metal leaving a surface ready to prepare for painting or welding.

Easy to work with

AR5100 is PH neutral (not acidic) and is not toxic. AR5100 solution can be reused many times until its chemistry is depleted. AR5100 will not harm most plastics, rubbers and paints (test on concealed surface before use).

Metal oxides pulled from the surface by strong bond

AR5100 works through a process called chelation in which a large synthetic molecule forms a strong bond with metal oxides (rust), but not with the host metal, and then pulls the rust from the surface.


AR5100 will work at temperatures between 65F and 160F, if the solution is too cold it will not be effective. AR5100 will remove bluing and galvanization. AR5100 will change the finish on high carbon steel to a dark patina. Immersion tanks and other containers used to store the mixed solution must be constructed of stainless steel or other corrosion resistant materials.

AR5100 Frequently Asked Questions

Can I use AR5100 by itself without diluting with water?

No, you have to mix AR5100 with water for it to be effective.

If I mix AR5100 with less water to create a higher concentration solution (or add extra AR5100 to the 15:1 mixture) will it be more effective?

No, AR5100 will not be more effective by creating a more concentrated solution.

Customer Reviews

Based on 10 reviews
Jeff H.
crankshaft rust

I had some Harley crankshafts that had been sitting in my barn for 10 years, very rusty, put them in a tub with this stuff and they came out looking like new. totally amazed. just ordered some more

GREG M. (Post Falls, ID, US)

Works great on motorcycle gas tanks.

L. Q. (Port Orchard, WA, US)
Works as advertised.

Used AR5100 to remove rust on a coolant transfer tube for my 1949 Oliver HG. Did it as a comparison with an identical part in similar condition to the competition. The AR-5100 did a fine job and seemed to be modestly more aggressive than the other product. Part came out cleaner and brighter. Overall works very well. See my comparison on Instagram @oldtruckswork.

Matt K. (Dorchester, MA, US)

Worked very well to clean up a couple of old gas tanks from a couple of antique lawnmowers I have !! Super product like all of the archoil line !

Allan L.J. (Denver, CO, US)
Archoil 5100 Rust remover worked beautifully

Brake rotors and drums never cut from 1998 Ranger were seriously rusty. 24 Hr soak in 5100 cleaned them like new, and minor cleanup machining made them perfect. Normal ARCHOIL product - it just works!