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topic 26899, p2

What Metals Rust the Fastest (Steel, Copper, Bronze)



1     2




An ongoing discussion from 2003 but continuing through 2018; some of these grammar schoolers are probably working on their Masters by now

February 19, 2013

Q. Hi
I have to do a science experiment, "Which metal corrodes the fastest in water"
Do you have any tips on how I could do this? Or which metals I could use? Any tips/ information will be greatly appreciated.
I am going to test them in tap water in an indoor shaded environment, in containers of equal sizes and capacity of water. I don't think it is feasible to make this large amount of distilled water and purchasing it in my area is quite costly (unfortunately).
Lastly: should I use plates or wires? I think I should use wires but please tell me the better one.
Thank you :)

Osama [last name deleted for privacy by Editor]
- Sydney, NSW, Australia


April 21, 2013

Q. Hello,
I am going to be doing a 10th grade chemistry experiment with a partner that has to do along the lines with:
-What metal rusts easily
-What can easily remove the rust and the amount of metal composition that has been removed during the rust removing process
-What solution/chemical composition has retarded/sped up the renewal of rust on the metal
I know what exactly my partner and I are going to use and what we to do but the question is what metal do we use to easily demonstrate the easiness/hardness of removing rusts with different chemical compositions/solutions. Do you have any idea that help us bring our science project "to life" as you may. Any ideas will be very helpful in this.

Edward [last name deleted for privacy by Editor]
- North Hollywood, California, United States


April 22, 2013

A. Hi. I think you bring a project to life by picking something that already fascinates you. If you pick something that hasn't grabbed your interest by 10th grade (metal rusting ... ho hum), it probably won't now; and if you're not interested, it's hard to interest others. Try to think of your past or present hobbies, interests, models, etc., and how rust might have surprised, interested, confused, or inconvenienced you. Maybe your interest was bottle caps, model boats, electric trains, old cars, yard art, antiques, old computers, political buttons, musical instruments, magic tricks, or whatever. You probably won't convincingly feign enthusiasm. Think hard about what already interests you and how rust might impact it. Good luck.

Regards,

Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


October 3, 2013

Q. I have the same project. But I will test steel and iron but what other metal should I use?

Grant M [last name deleted for privacy by Editor]
- Danielsville, Georgia, U.S.


November 9, 2013

Q. How long does it take for iron or steel to rust?

Bobby T [last name deleted for privacy by Editor]
- Washington, DC USA


November 11, 2013

A. Hi Bobby. The Iron Bridge crossing the River Severn in Shropshire, England has been standing since 1781. But steel and iron can flash rust in 15 minutes -- so it depends on a lot of things.

But if you are asking how long it will take a plain iron or steel nail to rust when immersed in water for a science project, I think you'll see rust in one to two days. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


January 10, 2014

Q. I've read this entire thread and really appreciate all the information. For my son's science project he tested how long it takes for a bronze coated steel fishhook to rust. The liquids he used were saltwater, fresh water, coke, gatorade, and apple juice. Only the salt & fresh water hooks rusted; the others all showed signs of corrosion (black spots on the bronze finish). I'm trying to help him determine what would cause the salt and fresh water hooks to rust since we know (after reading the posts) that bronze does not rust. Why would the bronze finish break-down allowing the steel hook to rust? Would greatly appreciate some insight. Thanks!

Malynda Vassallo
- Diamondhead, Mississippi, USA


January 2014

A. Hi Malyda. While wearing goggles, snip or sand the barb off those hooks before using them in a kid's science project -- you're making me queasy :-) Although the ancients used bronze fish hooks, you are correct that today's "bronze" hooks are made of steel and are merely the color of bronze. I suspect that bronze hooks are not electroplated with bronze, but simply dipped in a bronze colored lacquer, but would appreciate if someone who works at a fishing tackle company would weigh in on this.

The sentiment on a number of fishing forums is that bronze hooks are the cheapest and least durable of any common finish. A Maryland DNR study found that no fish hooks dissolve away in a practical time period, but that bronze lacquer hooks may be the safest for fish, but probably not by a statistically provable margin (articles.baltimoresun.com/1991-03-20/sports/1991079022_1_barbless-hooks-hook-styles-smaller-fish)

This bronze lacquer is apparently not very impermeable, and does permit the underlying steel hook to pretty rapidly rust, so that's why they are rusting.

Coke, Gatorade, and Apple Juice are all mild acids (www.21stcenturydental.com/smith/education/pH_drinks.html). Rust is more soluble in acids than steel is, with the result that things may not look rusty even if they are corroding faster than they are corroding in water because the rust is dissolved and not visible. When the Coke, Gatorade, and Apple Juice eventually evaporate away, you should see significant rust in the residue.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



June 5, 2014

Q. Hi my name is Bianca and I am a little flummoxed as to where to start on my 15 year old nephew's science project. We need all the help we can get because it is detrimental for his school certificate. It's about testing a factor that may affect the reaction rate of a metal/acid reaction. Which would be easier to choose and how do I begin?
1. Concentration of the acid: more concentrated acids increase the reaction rate.
2. Surface area of the metal: a larger surface area increases reaction rate.
3. The type of acid: more active acids increase the reaction rate.
4. The type of metal: more active metals increase the reaction rate.

PLEASE HELP.

Bianca V [last name deleted for privacy by Editor]
- Sydney, NSW, Australia


June 2014

A. Hi Bianca. Unlike your nephew and his fellow students, you haven't been attending science class and covering the subject in school (and receiving those little hints from the teacher), so I would expect you to be having a lot more difficulty with it than them :-)

First things first, are you sure he 100% understands the question? 100%. It's fine to ask a question if don't know the answer, but it only adds still more confusion for him to ask for an answer to a question that he doesn't understand.

Assuming he's past that hurdle, it looks like he's been offered the option to demonstrate any of four factors that affect the reaction rate. I can easily think of two more factors: temperature and agitation. So after he picks one, he has to make sure he can hold the other factors constant, because if they vary they may screw up the cause-and-effect results.

Do any of the 4 factors interest him? Interest is key to a good project! Most kids are more interested in "3." & "4." than the others. But "3." can be very hard to do in some of today's chemophobic classrooms, where real chemicals are often forbidden and the children are expected to learn chemistry from playing with secret recipes like Gatorade & Dr. Pepper (how do you know the acid is responsible for differences when you don't even know what chemicals are in secret recipes? -- it's ridiculous). So "4" is perhaps the project you'd better do for/with him. You can read on this page some of the great approaches to doing "3." or "4.", or combining them, by kids his age and even younger. Also, make sure you have his Science book in hand when you do this, because if you express anything that contradicts the language of his textbook there will probably be demerits. Good luck!

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



September 25, 2014

Q. What metal corrodes the fastest? I am doing an experiment on how fast can a nail corrode in 3 different substances. They are water, salt water, and hydrogen peroxide. What kind of nail should I use?

sophia e [last name deleted for privacy by Editor]
- little rock arkansas USA


September 2014

A. Hi Sophia. Try to find plain "cut" masonry nails if you can. These are hardened steel with no corrosion proofing. But if you don't readily find them, then just "bright finish" nails.

What you need to avoid is "roofing nails" or "hot dip galvanized" nails as these are as corrosion proof as practical; and you also don't want stainless steel, or aluminum, or painted "paneling" nails.

But be careful in describing your project! Although you want a metal that corrodes fast in order to speed the project along, your subject is NOT what metal corrodes the fastest; your project is which of those three materials corrodes steel nails fastest. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


October 21, 2014

Q. I'm 12. I was wondering if rust can be made from different types of iron, steel, etc. If so, how?

ella j [last name deleted for privacy by Editor]
- george town,tasmania


October 2014

A. Hi Ella. There is a lot of info on this page already. Simply putting a steel or iron nail, or steel wool into water, salt water, or bleach will make it start to rust within a couple of days.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


October 23, 2014

The cut nails are by far the best ones to use, but while there is no intentional preservative on them, most are heavily oxidized. Make them shiny with steel wool.

Bright nails normally have a thin coat of zinc electroplated on them, Here again, make them bright steel by a lot of rubbing with steel wool. If you want to make sure that you have removed all of it, put a sample nail in vinegar about half way up the nail. Watch for changes.

Since it takes oxygen for steel or iron to rust, you will need to completely submerge the nail or have identical amounts of the nail submerged. Do not put more than one nail per liquid sample.
Dissolved oxygen in the water will provide oxygen. You might want to try boiled water for another solution. Be sure to use Distilled water and not "purified water" which normally has ozone added. Tap water is very inconsistent, so unless you identify the time and place it is not a valid entry.
Test tubes will work best and a science teacher in you school should be able to loan you them. Your teacher might not but another might.
Identical temperatures are also needed so chose the location wisely.

James Watts
- Navarre, Florida



November 2, 2014

Q. Hello,
I am in 10th grade and doing a science fair project for my school. The focus of my project is around a question something like: "Does the type of metal impact the rate of oxidation and which methods are most effective at preventing rust for such metals?" My first problem is that I do not know which 3 metals to test. Due to the fact that only iron and steel rust, if I made a third metal be copper, would it make the experiment not balanced in the way that not all the same thing is being tested? The degree of rust on the metals will be rated according to a specific and detailed rust scale that I will make myself. Is there any other way to measure the degree of rust? I have seen ratings of rust for Stages 1-4 but I need something far more specific. I plan on having a constant of each metal, seeing how much it rusts. Then for each metal I want to apply 3 different methods of rust prevention. Overall, this will determine which method is the most effective for each method by seeing its relation to the constant's rust rating to the rust rating of the metal that endured a method of prevention. Any ideas for methods of prevention? I want methods that are different but feasible such as one being a store-bought prevention product and another being a home made coating of some sort. Also, what will be the best way to have these metals endure conditions that cause rust? Submerging them in salt water? I would really appreciate a reply, thanks.

Matthew [last name deleted for privacy by Editor]
- Westerly, Rhode Island, U.S.A.


November 2014

A. Hi Matthew. Either fresh tap water or salt water can be used as the corroding medium, either with full immersion or periodic spritzing. Vinegar will corrode metals but will dissolve rust faster than metal, confusing the issue.

The precious metals (gold, platinum, etc.) will not ever corrode. Copper, brass, zinc, nickel, tin and aluminum will corrode, but not rust.

But I don't think you'll want an experiment with multiple variables like all kinds of metals, all kinds of corrosion conditions, and all kinds of preservation techniques. I think it will be better to pick one metal (maybe steel nails), and one exposure condition (salt water OR fresh water, spritzing OR full immersion) if you intend to try multiple corrosion-proofing methods.

Corrosion-proofing methods could include a variety of store-bought paints, vs. dipping in grease, dipping in melted chocolate, waxing, etc.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


November 2, 2014

Q. As a follow up to my last post, I want to rust the metals using full immersion. A major reason being it will rust the metals to a greater degree and quicker than spritzing. However, a major disadvantage to full immersion is that it limits the methods of prevention that can be used, as methods like a protective paste or coating will not still be adhesive after immersed in water. With only a experiment time span of around November to late January, will spritzing cause rust of a severe enough degree that there will be a difference when a prevention technique is applied? I have to review this problem and the problem with limited prevention methods with full immersion with my science teacher. Also, because metals like copper corrode rather than rust, do you consider rusting and corroding similar enough to be rated on the same type of scale? Does rusting and corroding happen for the same reasons/causes? Also, as you mentioned I stay closer to one variable for each topic, I plan to stay with one kind of corrosion condition, but my teacher will not allow me to stay with one metal; she believes I must expand by testing several metals with several methods. Your suggestions for simple corrosion-proofing techniques seem interesting and possibly applicable!

Matthew [returning]
- Westerly, Rhode Island, U.S.A.


November 17, 2014

Q. I am a 10 year old. I want to know which metal will rust fastest (zinc, iron, or aluminum)? I need each one in salt water or tap water.

isaiyah g [last name deleted for privacy by Editor]
- Wilmington, North Carolina,USA


November 2014

A. Hi Isaiyah. Please have a parent read and interpret this page for you because it has been explained many times on this page that zinc and aluminum cannot rust (although they can corrode). Yes, you need each one in salt water or tap water -- so start a lab book, writing down everything you do and observe. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



December 29, 2014

Q. Which Corrodes faster -- steel of higher grade or lower grade? And why?

Dayo Osa
- Odessa, Texas, US


December 2014

A. Hi Osa. If by "higher grade" you mean a more expensive alloy steel with significants amounts of nickel, chrome, or other alloying materials in it, the higher grade steel will corrode slower. A basic reason is that these other metals are not as corrosion-prone as iron, and they form tighter and more adherent corrosion products. 18% chrome essentially makes type 400 stainless steel; 18% chrome and 8% nickel makes type 304 stainless steel.

Even a small amount of alloying metal, like 2% copper or 3.5% nickel can significantly reduce corrosion.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


sidebar December 30, 2014

Q. Thanks Ted.
So, if I were to make a pipe out of two steel materials, one with more alloy material in it than the other, and they both had the same thickness, which one of them would be more prone to bursting under pressure?

Dayo Osa [returning]
- Odessa, Texas, US


December 2014

A. Hi again Dayo. You do realize that you have now asked an entirely different question, I hope?

Corrosion allowance is a minor factor in a pipe design, and the ultimate strength of steels is not closely related to their alloy content. There are many issues involved in material selection besides ultimate strength, which is why you see so much copper piping and plastic piping. And you need to be very careful if trying to equate maximum allowable pressure with ultimate strength because materials are generally sized based on their yield strength rather than their ultimate strength. Further, the strongest and hardest materials may be unsuitable for pipe, both because of the difficulty of fabricating such materials (how do you cut the threads if the pipe is as hard as a file?) and the fact that you don't want pipes made of brittle materials (consider files and drills; they're very strong and hard, but subject to cracking like glass instead of bending). A pipe failing with a slightly split seam after decades of use is still a problem, but a pipe made of brittle hardened steel bursting like a hand grenade would be a catastrophe.

Please explain your situation. There's a big difference between a student question about a general theory, and practical design issues. Thanks.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


26899
January 3, 2015

Q. For my son's 9th grade science fair project, he put samples of dissimilar metals in a corrosive environment, iron and copper. For some he added a zinc as a sacrificial anode (penny with the copper removed). On a lark, I suggested taking some of the pennies and bending them back and forth a bit before attaching them. We found the bent pennies corroded a lot quicker than the non-bent pennies, though we aren't sure why. Does the bending create more surface area? Does it affect the crystalline structure, which impacts the corrosion? Can you suggest an experimental way to figure this out?
Thanks! Scott

Scott Lucero
- Alexandria, Virginia USA


Hi Scott. Putting metal into tension does affect the structure and cause galvanic hot spots. The bending also might have increased the surface area. Unfortunately I don't know a quick and easy way to tell which was the more dominant factor. It might be possible to anneal the zinc to remove the stresses and see what happens then.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



February 27, 2015

Q. I am 20 years old and working on a project for my architectural studio class and I am looking up different materials to use on our structure. Looking into different metals, I was wondering what were some of the pros and cons to using Steel, copper, and/or bronze -- taking weather and aging into account. The part that the metal would be used for would be ribs for a bike rack on the outside of the structure.

nathan adams
- Lincoln, Nebraska, USA


February 2015

A. Hi Nathan. Steel will quickly rust unless it receives proper pretreatment and finish, but copper and bronze will not remain attractive unless properly finished either. Copper and bronze are so much more expensive than steel that their architectural uses are quite limited.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



March 1, 2015 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. I am doing an actual experiment involving which will rust--steel, copper, and bronze. I need to obtain the metals, but I am not sure how much/which form of each metal I need to get and exactly which type of each. Could you please advise? I was looking at onlinemetals.com/ to try to order.

Thank you!!

John Y [last name deleted for privacy by Editor]
11th grader - Shannon, Georgia USA


February 2015

A. Hello John. we appended your inquiry to a long thread which covers it rather completely and offers some other sources. For the purposes of such a test, I don't think it much matters what type of steel, copper, and bronze you get; go for the cheapest, but carefully retain full detail on what you get. What you'll be looking to get from this experiment is not so much the specific result as learning how to properly undertake such projects -- which will include documenting information as accurately as possible. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



March 13, 2015

Hi, I'm Charlotte and for my science project I need help. Why can Iron rust but not Bronze and why does Bronze last for so long. Thanks so much! P.S could you help me soon because its due in 2 days!

Charlotte Faeste
- Sydney Australia


March 2015

Hi Charlotte. One reason this page is so darned long is because we've answered that question of why bronze can't rust again and again and again and again :-)

Although you might not know how long it will take for a piece of old chicken to become rotting chicken, you do know how long it will take for an old tomato to become rotting chicken: never ever, because tomatoes aren't chicken.

Rust is rotted iron. How long will it take for bronze (which is a different metal than iron) to become rust (rotted iron): never ever. Bronze and other metals can rot, corrode, tarnish, whatever -- but they can never rust because rust is defined as oxides of iron, the corrosion product of iron, rotting iron.

Bronze lasts a long time because when it begins to corrode, the oxides of bronze tend to be adherent and solid, so you have a thin coating of corroded bronze on the rest of the bronze that keeps air and water from getting to the underlying bronze and continuing the corrosion. That is, the corrosion products tend to seal away the bronze from the environment.

The corrosion products of iron, though, are non adherent, loose, fluffy, and hydroscopic (suck up water, keeping the iron wet) so the iron stays in contact with the air and water and just keeps corroding. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



April 9, 2015

Q. Hello, My name is Angel, I am 16 almost 17, and I am doing a coin project for my chemistry in the Community class, I am making a coin and I need to figure out when and how gold, silver, platinum, copper and zinc corrode or tarnish, and how long they last. My coin is coated with 10% of each of the metals and 60% zinc for the center, its as heavy as holding 21 pennies, and the thickness is 3.00 mm, and mass 52.5 g, and diameter is 5 cm, can you please help me? Thank you if you can~ =^vv^=

Angel H [last name deleted for privacy by Editor]
- Wautoma, Wisconsin, USA


April 2015

"But I was a mere lad of sixteen
-- I've aged a year since then."

A. Hi Angel. Thank you for reminding an old man of a favorite song from way back when ... =>

Gold and platinum don't corrode -- they'll last almost forever. How long other metals last depends on their environment.

I don't understand what you are trying to ask with your percentages and dimensions. What is the question?

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


November 13, 2015

Q. Do metals rust faster due to their number of protons?

Jacob T [last name deleted for privacy by Editor]
- Madison, Wisconsin, United States of America


26899-3
January 2016

Hi Jacob. No, I don't see such a pattern. Here for example are the elements with 26 through 30 protons =>

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


December 5, 2015

Q. My science fair project is also on which metal will rust fastest. I used steel, iron, and bronze as my metals. The steel rusted fastest but I don't know how to capture the data. How do I capture the data for tables, charts, and graphs?

Noah G [last name deleted for privacy by Editor]
- Washington, DC


January 2016

A. Hi Noah. When we are trying to express something in a foreign language which we are not yet fluent in, we usually have to think it all through in English, and then try translating it a word at a time. Tables and graphs are languages used to convey information, that you're not yet fluent in, so you'll probably need to express your results in words first.

"The steel rusted fastest" isn't enough info/data to bother trying to put into a table or graph. Tell us in words what data you have accumulated and we can help you build a table or graph that captures it. Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



January 13, 2016

Q. Hi, my name is Sofia and I am 11, in Gr. 5. For our science fair project, at first, we thought of finding out which from 3 nails would rust the fastest in water. We didn't think of what metals we'd use for our nails when we were going to try to but, my teacher thought of another project for us, it was to test out if stress on metals by pressure does really make them rust (because he heard it does) and then, how he said we could test that was by dropping a hammer from a high height to a metal can and observing if it rusts.

But then, when I researched about the project he thought of, the kind of corrosion he was talking about was Stress Corrosion Cracking and I found out about it that when metals experience it, it doesn't rust and just gets cracks so I thought, "Okay, when hitting the metal can, after, we'll just observe for cracks instead then but then later on, I found out it takes very long for the cracks to become big enough and noticeable and that when they are small, it is invisible and can only be detected by this process called mdi or something and that process.

I really think our group can't do it, it requires super expensive stuff and then I also found out that hitting does not stress out metals but these confusing and unsafe liquids do so, the project teacher thought of was a super no-no. So, I just thought we can go back to our old project but it's like so common and typical so I just thought of 2 more experiments that might be better:
- Finding out which is the best way to prevent rust from ways I found on the internet and - for 2nd one I thought of but this time on removing rust.

Please help me choose the best one from the 2 new project ideas I thought of and the old idea. Or please, suggest another project! Thank you, I am so sorry for the long post.

Sofia P [last name deleted for privacy by Editor]
- Pasig City, Philippines


January 2016

A. Hi Sofia. Unless you find it uninteresting, I'd go back to the original and please the teacher. Stresses not only cause stress corrosion cracking, they also cause galvanic "hot spots" -- areas that will rust or corrode in water or acid faster than the rest of the metal ... As an aside, if you connect zinc and steel and put them in saltwater or a mild acid like vinegar or lemon juice, the zinc will corrode to prevent the steel from corroding. If you put some connected steel and copper into the saltwater or vinegar, the steel will corrode to protect the copper. Now back to your project ...

If you highly stress a metal, the area in tension will sacrificially corrode to protect the rest of the metal. You might try putting one piece of stressed metal into a jar of salt water, another into a jar of vinegar, another into a jar of lemon juice. Then take a piece of unstressed metal and put it in saltwater, another in vinegar, another is lemon juice and see if whacking the heck out of it did indeed make galvanic hot spots that led to quicker corrosion. Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



March 27, 2016

Q. Hi. I was wondering what is the name for copper corrosion and silver corrosion.

DEBRA A [last name deleted for privacy by Editor]
- Toronto, Ontario, Canada


March 2016

A. Hi Debra. I don't think they have any really special names. "Tarnish" or "corrosion" is just about it. The reason that iron/steel corrosion has the special name "rust" is probably just that there is much more iron and steel in the world than copper and silver, and corrosion of iron and steel is a much bigger problem for at least two big reasons:
1. Corrosion of steel is usually faster and more severe that the corrosion of other metals largely because the corrosion product is dusty and flaky and hydroscopic (water absorbing) and doesn't slow the corrosion (the presences of rust leads to more rust), whereas the corrosion products of copper and silver may be tenacious and slow down the ongoing corrosion.
2. Steel is often used for structural purposes. A bridge or building or ship can collapse if there is too much rust.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


March 29, 2016

A. Debra,
Copper oxide corrosion on copper and copper alloys is sometimes known as "patina".

I don't believe that silver tarnish goes by any other names, but instead I'll give you a bit of trivia. Contrary to most other forms of corrosion, silver tarnish is NOT silver oxide! It is in fact silver sulfide. (One of my professors back in grad school said his family's silver never tarnished until a factory was built in town.)

Bonus trivia! Rather than removing silver tarnish abrasively with polish, it is easier to remove it electrochemically using a hot water bath with some electrolyte (usually baking soda) mixed in, and some aluminum!

ray kremer
Ray Kremer
Stellar Solutions, Inc.
supporting advertiser
McHenry, Illinois
stellar solutions banner



May 24, 2016

Q. I have enjoyed reading this thread of many years! I've learned from it and have a few questions. I designed a stainless steel bottle stopper for artists to put their artistic creations on the top. It started 10 years ago (accidental business!) and I have learned a lot about the grades and chemical percentages in stainless steel.

A customer requested brass stoppers, a metallurgist for a local company said he saw no reason why I couldn't use brass as there are brass wine goblets. My stoppers are used in olive oil bottles, wine, liquor, bath oil and herbal vinegar bottles.

I know brass will tarnish but that's a sort of even and slow process but, before I put brass stoppers in my inventory, can anyone tell me if it will rust or get ugly spots or???

Thank you

Ruth Niles
Niles Bottle Stoppers - Newville, Pennsylvania


May 2016

A. Hi Ruth. Per www.fda.gov/Food/GuidanceRegulation/RetailFoodProtection/FoodCode/ucm188064.htm

26899-2
it seems to be a no-go for the herbal vinegar, but it should be fine for the oils. Sorry, I don't know about wine & liquor.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


May 25, 2016

A. Actually, you don't have to make the stoppers out of brass. Suggest you make them out of stainless steel, and apply a PVD coating that looks just like brass. Of course, it won't scratch as easily as brass (or stainless steel), and won't tarnish... One other issue to consider is lead. Most brass alloys contain lead -- it makes them more machinable. In the faucet business the lead content is severely limited in waterways (pipes, spouts, shower heads, and the like).

jim treglio portrait
Jim Treglio
PVD Consultant - San Diego, California



June 24, 2016

Q. Which will corrode first, carbon steel or alloy steel?

kalyan vignesh
- Mumbai, Maharastra, India


June 2016

A. Hi kalyan. "Carbon steel" means plain steel. "Alloy steel" means steel with other metals alloyed into it like nickel and chromium. If there is a substantial amount of these other metals, the corrosion resistance is improved significantly -- both because the alloy is less prone to corrosion and because the corrosion products that do form will tend to be more impervious and less dusty than regular rust. In such cases the alloy steel is often called stainless steel or corrosion resistant steel.

The term can also mean "low alloy steel, i.e., steel with only a small percentage of those other metals; if the percentage is quite small, the effect is probably small.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



August 19, 2016

Q. Hi, I'm jack and I'm 8 years old. I have a question too. I can't think of any examples of electrolysis and I really need at least one. Thank you

jack l
- uk, ahford


wikipedia
Electrolysis
August 2016

A. Hi Jack. Wikipedia lists a good number of examples =>
But are you sure your teacher defines 'electrolysis' the same way Wikipedia does? If you answer a question without really understanding the question, it's a disservice to your own education and to your teacher. Are you positive that you can answer the question "What is Electrolysis?". If not, ask your teacher the question before you try to answer it. Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



January 20, 2018

Q. Dear Sir
I have to replace some old brass valves and unions, 1-inch size, connected to a carbon steel nipple that is welded to 12-inch carbon steel chilled water pipeline. I would like to know whether I have to use new brass fittings again or use stainless steel fittings on the existing carbon steel nipple ... my aim is to protect the nipple to avoid draining the system for re-welding jobs in case the nipple gets corroded.
Best Regards

ISSA ALRABADI
- Jeddah-KSA, from Jordan


March 11, 2018

A. Ted, I think you are getting caught up in semantics. If you define rusting as/is the definition which is Fe + O = FeO2 you are correct. But many metals oxidize! Why don't you explain that to anyone? It's obvious from these posts that peeps are confusing rusting and oxidation. Why don't you explain that when metals tarnish, such as copper, it forms a greenish patina of copper oxide that forms on the outside surface of the exposed metal to atmospheric oxygen and moisture. This patina actually helps to protect the remaining underlying metal from future corrosion.

Brian wilstermann
I'm a machinist - Dallas Texas America


March 13, 2018

Brian

If you read a number of relevant threads you will get an understanding of how many times Ted has done what you are asking for.

Willie Alexander
- Green Mountain Falls, Colorado


March 2018

thumbs up sign Thanks Willie. While new readers viewing just one of thousands of threads are likely to feel that too much has been left unsaid, regular readers are probably bored to death by my repetitions.

That's about the worst problem I face -- so I've got a damn fine job! ... and I'm truly thankful to guys like you for making it possible :-)

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"



March 22, 2018

Q. Hi, I am doing a science project and i need to figure out which household metal rusts the fastest. I need to get my hands on some of them FAST!

Alicia L [last name deleted for privacy by Editor]
- Sydney, NSW, Australia


Metal Samples

March 2018

A. Hi Alicia. Aluminum foil and aluminum cans are available in many households. Coins are everywhere. Keys are getting less common in the digital age, but usually available. Steel cans are sometimes used for coffee or juices. Fastening hardware (nuts, screws, washers) are in everyone's junk drawer.

The two issues with most of these items will be using sandpaper to remove any coating on them so you have the base metal to work with, and finding out what metal they are made of. Most hardware is steel underneath the coating or plating on it. Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


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