Removal of Surface Rust

[9F94M567042]

Hi Everyone,

Apologies if this has been discussed prior. Looking for advice/techniques on treating and the removal of minor surface rust from interior pieces. I recently moved to a wetter climate and now have notice some parts I had stored have surface rust on them now. They range from metal dash parts to engine parts.

What do all of you folks use to remove and then treat so it doesn't return?

Appricate any advice on what products to use and opinions.

Thanks

[JFranklin]

Clean loose rust, treat with OSPHO, and paint.

[Tom Boehm]

I am a big fan of Evapo Rust. It is a non toxic water based rust remover. It will work good on the light surface rust you describe. The parts must be soaked in a container of Evapo Rust. It has an ingredient to prevent flash rust for a while after treatment. It is best to paint the parts while clean. It is not supposed to remove good paint or plating. My experience is that it will take off paint but not plating. Engine parts that are not to be painted can be sprayed with PB Blaster. I don't think that evaporates like WD-40. 

I live in the midwest.  I had the same problem with parts rusting in storage and the top of my table saw had light rust on it. I went all out to solve the problem. I insulated and finished the walls in my workshop. I got doors and windows that seal better. I got a window air conditioner and a dehumidifier. The portable dehumidifier was the single most effective means to solve the humidity/ rusting problem.

[joe_padavano]

All of these products are just phosphoric acid. Read the MSDS sheets. There are less expensive ways to achieve the same results.

Edited July 30, 2021 by joe_padavano (see edit history)

[Tom Boehm]

At about $20 - $22 a gallon, Evapo Rust is a little expensive. It will not eat into unrusted steel if you need to soak it for a long time unlike phosphoric acid. I looked at the msds on the website and it did not say it was phosphoric acid. How do you know that? I don't know. I always assumed it was not. 

[JFranklin]

3 hours ago, joe_padavano said:

All of these products are just phosphoric acid. Read the MSDS sheets. There are less expensive ways to achieve the same results.

OK, don't tease!

[JACK M]

Molasses.

mixed with water at around 6 to one.

Get it cheap at your local farm store.

Soak for a week or two.

You will not be disappointed.

[Buick35]

I was told white vinegar and water works.I tried it and it does.Mix it about 8/1.8 being the vinegar.

[Bloo]

Evaporust is *NOT* phosphoric acid. I see this come up again and again in the forum. I have probably seen and used every new "miracle" phosphoric acid rust remover to come down the pike in the last 40 or more years, and their characteristics are all similar. Evaporust is *NOT* the same. There are some pretty glaring differences.

 

All of these phosphoric acid cures will eventually stop eating rust and form a hard black skin over the top. They advertise this as "rust conversion" but if you break through it, there is still rust under there. Removing rust always involves multiple cleanings with a wire brush or whatever and will never quite get to the bottom of all the pits thanks to this skinning behavior.

 

Unlike phosphoric acid, Evaporust is not really suitable for parts that cannot be immersed. You can try to soak paper towels with it and wrap in plastic, or even arrange a drip. It is extremely slow, fiddly and does not work very well. They may even have a product for this type of use, but I would be skeptical.

 

If you can immerse the part in Evaporust, the rust turns to a black powder and falls into the bottom of the vat. It WILL get all the way to the bottom of the pits. It will get there a lot faster if you take the part out now and then rinse any of that loose black powder off that may be slowing things down. Either way, the reaction will continue until all the rust is gone. It works faster when warmer, and if it gets too cool the reaction temporarily stops. You want this stuff in a warm room. If you leave the part in "too long", or intentionally leave it in a long time to insure you got all the way to the bottom of every pit, the part will turn black. This is harmless, and does not resemble the crust from phosphoric acid. Most will wash off, but what remains will resemble discoloration from heat or gun bluing.

 

The black powder falling off of a part in Evaporust most closely resembles what happens in an electrolytic derusting vat. Electrolytic derusting is much cheaper, and therefore doable on a larger scale. The downside is that there is somewhat of a "line of sight" problem, and areas that are farther away from the electrodes may not get completely done. For instance, the internal areas of a rusty door or trunk latch mechanism might not ever get completely done. Evaporust has no such limitation but is expensive, so better for smaller projects.

 

FInally, phosphoric acid burns your hands, while Evaporust is watery and sticky. Phosphoric acid fumes are acid fumes, while Evaporust fumes are not very strong and are sickly sweet.

 

If Evaporust is related to any old time method, then it must be related to molasses. It resembles sugar more than anything else. It turns to a nasty sticky goo if it dries, but washes off because it is soluble in water. When my vat leaked a little the ants went crazy for it at first, and then decided they didn't like it.

 

 

Edited May 31, 2023 by Bloo (see edit history)

[Rusty_OToole]

Vinegar or CLR will remove rust without damage to paint. Once is is cleaned up you can wax or clear coat. If it is real bad then more aggressive cures, and repainting will be needed.

[MochetVelo]

You can apply Evaporust to larger parts with a small water pump to recirculate the liquid. A length of perforated hose will flow the product onto a fender, for example.

[Bloo]

And it works... lousy, but it still comes without all the disadvantages of phosphoric acid. I have done this and will probably do it again, but plan for it to take a long time, lose a lot of liquid, and need constant babysitting. It also ruins some pumps. The magic comes when you can submerge the parts. If you can do that, nothing else really comes close.

[Rivguy]

I used straight vinegar from Walmart to remove surface rust from the top surfaces of my car. Take a section of old bath towel, soak it in vinegar, wring a bit, lay directly on top of the metal. Add more vinegar to keep the towel wet for a couple of hours. Let sit overnight and dry. The rust bubbles up and dries into a red crust. I hit the surface with a wire brush to remove the crust. You can repeat this step again if needed. I wiped it down again with vinegar. Then I neutralized the vinegar by wiping with with a baking soda solution and finally rinsing with plain water. I towel dried the surface. I sprayed it with some Rustoleum Rust Reformer primer that bonds with the rust and forms a (hopefully) moisture impervious coating. My hope is that this will protect the surface until I can have the car painted in a bodyshop. It should be easy enough to sand through the spray bomb coating when it's time to prep and paint. It came out pretty well. I can include some photos, but I have to figure how to post them.

[35cz8]

On 7/30/2021 at 12:10 PM, JACK M said:

Molasses.

mixed with water at around 6 to one.

Get it cheap at your local farm store.

Soak for a week or two.

You will not be disappointed.

I have used molasses for a couple of years and it has worked great.  I use one part molasses to 7 parts water and works good for me.  I have even soaked parts for a couple of weeks, then rinse them with a pressure nozzle on a garden hose and found part numbers I never were on the parts.  I am going to get another gallon soon because I have original nuts, bolts and washers and a few other small parts I want to remove the rust from.

[Eldovert]

I use citric acid. I have a big stainless pot that I throw on the stove with the parts and keep it heated on a low setting.You can de-rust something in a couple of hours. I have been doing this all week..cooking dash parts in a mild solution in the morning and priming them in the afternoon.

Cheers,Pat

[capgage]

Second on the molasses.  Essential for parts you don't want to blast.  I had a friend I recommended this to who had an old radio with a piano hinge.  Worked really well for him.  I've done it on road wheels.  Does NOT take off the chrome, but takes off the rust.  Did it on some 65's with center rings knocked out.  Only had to rechrome 1 of the 5.  Put them on a 58 for a brief time just for fun.

 

Really really good for delicate stuff though.  I think if you leave it in too long though, it will outdo its job and start to eat metal.  But that takes a LONG time.  Like months.

 

Be prepared for the smell though, while not God awful it is very strong and food/grease like and can turn some people's stomachs.

 

And it could take up to a month for the molasses/water to start to ferment.  You'll know when the smell comes.

 

[trini]

I soaked almost all small parts in vaporust. Works like a charm. Read the label for instructions. Do not leave instruments with writings for long . It will remove the delicate paints. From time to time you may have to help by using a wire brush and repeat.For large objects paint with brush  and do as if washing. Alternate with wire brushing. It may be expensive but is there an alternate ? Removing rust is always labour intensive. After rust is removed wash , blow dry and warm with a propane torch and paint of choice. It is better to do this job in less humidity. If your car rust bleeding on the body or any part use a small brush and wash paint until all rust is washed away.Very safe to use.      

[Artina46]

Hello Everyone,

I hope this message finds you well. Recently, I came across two products that claim to have the ability to transform rust and restore metal surfaces. I find myself in a dilemma and would greatly appreciate your advice on this matter. The products in question are OSPHO and Rust Convert .

 

If any of you have had the opportunity to use either of these products, I would be grateful to hear about your experiences and the results you achieved. Specifically, I am seeking insights on which product is more effective in transforming rust and providing long-term protection for metal surfaces.

 

Your valuable experiences and recommendations will play a significant role in helping me make an informed decision. Thank you all in advance for your kind assistance.

 

Best regards,

Artina46

[JFranklin]

I use OSPHO with no regrets on all bare metal after cleaning to stop any further rusting. It acts as a primer also under paints.

[TOM H. S.]

Concrete Prep Cleaner in a one gallon jug [ straight phosphoric acid ], when soaking an item in this acid it will only remove iron oxide ( EL Rusto ). Once rust is dissolved it stops eating the metal. It can eat under chrome plating to remove more rust so keep that in mind. Wear Gloves as it is acid. Using the electrolysis method is a safe low cost method as seen online by a number of folks on videos. I've used the non-acid type rust removers and they do work until the solution is saturated in the removed rust. If you let the liquid sit for a long time the rust particulates settle to the bottom of container. It's possible to put saturated solution in a centrifuge to draw out the particulates more quickly. White vinegar from grocery store is low % or from big box store as cleaner at 30% will dissolve rust and parent metal if soaked too long, as it is an acid. Muriatic Acid used to also clean concrete is very strong and will eat up what ever you put into it made of metal. Both Vinegar and Muriatic Acid will need to be rinsed off and neutralized with a solution of Baking Soda and Water to stop the acid action. In a pinch one can use Ketchup right out the bottle to treat small items; both because it has vinegar and tomato sauce which eats into rust. One note of the diluted Molasses that I've read else where, is that it is not recommended to soak Engine Blocks in it or any other Cast Iron cases etc. The above folks have great advise. Best Wishes.

 

[jp1gt]

I got 5 gallons of molasses and put some in a horse water trough for big parts. It works real well but you need to keep it in the sun. Also do not let the animals have access to it. The first batch I made the horses drank all of it!!

[BlueDevil]

Be sure it is far from your house. That stuff stinks.

[Restorer32]

These discussions make me appreciate our glass bead cabinet even more.

[60FlatTop]

Yesterday I looked a a rusty spare '60 Buick rim I have sitting around and thought "Maybe I should drop that off and have it sandblasted. I'll have them polyurethane primer it too".

 

What timing! Sometimes I amaze myself.

[BlueDevil]

Be sure it is far from your house. That stuff stinks.

[BlueDevil]

I am running an experiment with ATF/ACETONE/Evaporust. 

 

Here is the ATF/Acetone mix.

[BlueDevil]

Evaporate and AFT/Acetone appears to be immiscible liquids in that they don't mix. The Evaporust is heavier and sinks to the bottom. I am trying to free up a stuck engine.

 

Evaporust is a chelation product.

 

Evapo-Rust works through selective chelation. This is a process in which a large synthetic molecule forms a bond with metals and holds them in solution. Most chelating agents bind many different metals. The active ingredient in Evapo-Rust bonds exclusively to iron. (From theruststore.com).

 

My thought is this brew allows the Evaporust to eliminate the rust in a cylinder and the other 2 provide lubrication. I have a trial in the works. I will let you know in a week how it turns out.

[BlueDevil]

Here is a Pierce Arrow Flywheel, which I obviously had carefully stored.

 

Here before Evaporust

[BlueDevil]

Here it is after a couple days in evaporust

[edinmass]

Be careful with the flywheel…..it’s not indexed. 

[edinmass]

Also, you need to grind the surface and the pegs……or your clutch will chatter like hell, and snap an axel.