Best Rust Converter? POR-15, Eastwood, Rust-oleum Rust Reformer, Gempler's

One of my coworkers recommended this video to me, and I respect the video host's adherence to the scientific method. He tests metal from the same source, prepared in the same way, and has multiple test samples for each coating.

I'm not so sure, however, what these rust convertors actually do. I found this in the wikipedia article on rust converters...

Commercial rust converters are water-based and contain two primary active ingredients: tannic acid and an organic polymer. Tannic acid chemically converts the reddish iron oxides into bluish-black ferric tannate, a more stable material. The second active ingredient is an organic solvent such as 2-butoxyethanol (ethylene glycol monobutyl ether, trade name butyl cellosolve) that acts as a wetting agent and provides a protective primer layer in conjunction with an organic polymer emulsion. 

 

Some rust converters may contain additional acids to speed up the chemical reaction by lowering the pH of the solution. A common example is phosphoric acid, which additionally converts some iron oxide into an inert layer of ferric phosphate. Most of the rust converters contain special additives. They support the rust transformation and improve the wetting of the surface.

Looks like they're primarily tannic acid with some organic solvents.

The science seems pretty interesting, and I might show this video to my students when we discuss experimental design methods.

Reusable handwarmers that get hot by freezing

The title of this video is wrong.

There is no freezing happening. There is recrystallization happening from sodium acetate dissolved in solution.

That's not freezing - a pure liquid turning into a solid like ice turning into water. The host seems to understand that distinction, but he's sloppy on using the term freezing and freezing point somewhat misleadingly. He also is sloppy on liquid versus solution and melted versus dissolved.

Most of this video is an explanation and comparison of the two types of hand warmers - the reusable sodium acetate solution and the single-use iron rusting type. The video host explains the science behind what's happening and judges the single-use to be the better choice - something that I'll leave up to you.

I use both in class for different purposes and different chapters.

You Spend More on Rust Than Gasoline (Probably)

Heya, Grady. Always good to see ya.

Today's video isn't really all that special. There isn't much revolutionary here, but it's the first in a series about rust and corrosion that Grady has announced and that I'm looking forward to because his garage demos are consistently outstanding. He does show us some bolts in oxygen-rich salt water with time lapse corrosion rolling along. 

I'm looking forward to what he has coming in later installments.

2:37 / 4:58 FLAME COLORED COPPER…copper art time-lapse by Brent Artman

That's so pretty.

In summer camp and in our material science course at Princeton, we demonstrate this concept - that different portions of a flame produce different temperatures and different results - on a single copper sheet with one torch. We move the torch nearer to and further from the sheet and see reduction or oxidation.

But there's a lot more to using a flame to oxidize or reduce copper. In industry and - I think - in art, it's more common to adjust the mix of oxygen and fuel to change the flame between being oxidizing, neutral, and reducing (also known as carborizing). It's something that's done by plumbers when brazing together copper pipes.

Clearly, the video up top was made by someone who understands all this - maybe understands the science of it but certainly understands the practicality of it because Phoenix Flame Art (by Brent Artman - natch) uses the flame to produce some stunning artwork by preferentially oxidizing and reducing copper sheets.

@phoenix_flame_art Answer @liccalollipop Which group are you?? LINES OR NO LINES??? #PHOENIXFLAMEART #youchoose #contriversal #oneortheother #artinspo #poll #question #feedback #flameart #coldest @thecoldestwater ♬ FEEL THE GROOVE - Queens Road, Fabian Graetz

Anodizing Titanium - How To Anodize Titanium With 9V Batteries Cheap And Easy - Full Tutorial (2020)

That looks so simple...now I just need to find a source of titanium handy so we can do that in lab.

And I'm a little afraid of the rust remover because I read an article about hydrofluoric acid's dangers a while back.

But that really does look like something I could achieve.

I wonder what colors you can get...

Oh, thanks.

What is epoxy coated rebar and why is it being banned?

I feel bad for this youtuber having to broadcast to us from some sort of white void with bad lighting or white balance without understanding how low quality his image is compared to the quality of the images that he's sharing 'behind' him. And I don't know why he won't make eye contact with me. He keeps looking at something above and in front of me that I can't see.

Sorry for the snarkiness. 

I've been watching a lot of very professionally made YouTube videos recently, and it's easy to see how much better those look than this more amateurishly produced videos, but I will admit that this guy gives a great explanation of why epoxy coated rebar is used (corrosion prevention), the problems with it (the epoxy rubs off unless the rebar is handled very gently before sealing it in concrete leading to pitting corrosion and debonding), and pros and cons of possible solutions (high costs due to scale production and lack of building code acceptance).

It's easy to think that simple solutions (just paint the rebar) won't lead to secondary problems (the paint rubbing off).

(Oh, and respect to BadLandsKid who had the top comment on this video when I accessed it most recently, "Very galvanizing topic. While it’s not set in stone, it reinforced my views on rebar.")

Anodizing (Or the beauty of corrosion)

Hey, Bill.

This video - as promised earlier this week - gets into the explanation of how anodizing creates the beautiful colors via interference rather than by actual light absorption. 

It turns out that titanium and aluminum don't necessarily get tinted the same. Aluminum is often anodized and dyed.

Who knew?

Facinating metal rings change multiple colours.

Edit: I had hunted down a YouTube upload of the Reddit video I'm about to describe, but that upload disappeared before this post even appeared, so I'm just linking to the Reddit original. I do warn you that the title of the subreddit contains a nsfw word. It's titled blackmagicf***ery. You have been warned. The above video is less thrilling and contains some pretty annoying music though it does show the same concept of titanium anodization.

I originally found it on one of Reddit's unfortunately-named subreddits. That link is here, but I'll avoid embedding from the Reddit source so the inappropriate subreddit title won't show up here. You have been warned.

It is exactly the same video, however the reddit version is in slightly higher resolution.

Not much to say here other than that this is a bit of a teaser for a video I'm posting later this week that explains how anodizing works...

...and the new fad deadly among teenagers that you need to know.

Repairing broken water mains

One of our regular activities in the corrosion chapter of our material science course is to read and listen to this NPR story about our corroding water mains and the costs that would be involved in repairing or replacing the parts of the network in need. I start the lesson by watching video of one of the more spectacular water main breaks that I've seen, the 2014 break on the UCLA campus.

This year the students asked what it took to repair a water main break like that. 

In searching, I couldn't find the repair work for that specific water main, but I did find a few other videos - including one from Skoakie, IL, the same city as the NPR story linked above.

The secret of the aluminum can: what is it hiding?

That's some impressive can polishing right there.

This video from MEL Chemistry shows how to reveal the secret polymer liner that lives inside every pop can (or Coke can if you're from Southern Indiana like your friendly neighborhood blogger is) using 'drain cleaner.' I assume it's something like Drano, a very concentrated solution of primarily sodium hydroxide. 

I do this experiment in class using hydrochloric acid in the 3M range, and it works just fine. Aluminum is, however, soluble in both acids and bases (not typical of most metals), so I have heard that sodium hydroxide solutions can produce the same result. 

I would certainly be careful with the 'drain cleaner', folks, because it's some nasty stuff. Weirdly, I'm more comfortable using 3M HCl because it's something I use with fair regularity at school. The Drano, however, gives me a bit of an uneasy feeling. Oddly, though, Steve Spangler's video of the same demo also uses sodium hydroxide as did most of the other videos I found showing this demonstration. That might be because buying hydrochloric acid can be a bit tougher (unless you know it's also called muriatic acid and is available at most hardware stores.)

Either way, be careful if you try this at home, but it's pretty frickin' awesome to see.

ACME corrosion cell on a single piece of metal

Source - https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Chemistry_-_The_Central_Science_(Brown_et_al.)/20%3A_Electrochemistry/20.8%3A_Corrosion

I took a three-day, corrosion-focused ASM workshop at the University of Akron a few years back. It wasn't necessarily a part of the ASM summer camp world tour, but it was a certainly adjacent to the regular tour. ASM master teachers were teaching it - Andy and Debbie, honestly - and a solid handful of the attendees were ASM master teachers helping out and learning along the way.

That workshop was - I think - the first time that I ever heard the concept of ACME as it relates to corrosion.

By way of introduction, ACME is an acronym for Anode Cathode Metal Electrolyte. In order for corrosion (or oxidation and reduction) to happen, you must have...

• an anode (a more reactive metal)
• a cathode (a less reactive metal)
• a metal (sometimes called a metallic path connecting them)
• an electrolyte (a source of ions that keep the charge of the cell balances)

For example...

Source - https://www.marineinsight.com/tech/understanding-sacrificial-anodes-on-ships/

In the cell there...

• anode - zinc, more reactive than copper, loses electrons, turns from neutral zinc into zinc ions which drift into the solution around the zinc electrode
• cathode - copper, less reactive than zinc, gains electrons, gains mass as copper ions from the solution become neutral copper atoms
• metal - the wire between the zinc and copper electrodes, allows electrons to move from anode to cathode, can involve a thing (light bulb, radio, cell phone) that needs that flow of electrons to opperate
• electrolyte - the solutions around the electrodes and the porous disk that lets the ions move to keep the overall charge on each side of the disk to stay neutral, without it charge would build up and electrons would stop flowing

If this cell is set up, corrosion is going to happen, and the two electrodes don't have to be separated. They can be dissimilar metals abutting each other.

Source - https://pomametals.com/how-to-prevent-galvanic-corrosion/

Here we see two metals joined together (like a copper and a lead pipe connecting) with an electrolyte solution flowing through them. Bad things will happen to the more active (less noble) metal.

If we can break any connection in that cell, corrosion will stop (or at least be drastically arrested).

Source - https://pomametals.com/how-to-prevent-galvanic-corrosion/

After a few years of teaching corrosion in Princeton's material science course and the ASM summer camps and in AP chemistry, I think I'm finally getting to understand the ACME cell.

And I find myself thinking back to what one of the Akron professors said at that workshop when we asked how much of this they wanted us to teach to our students. He said that if students could understand that a single piece of metal could be both anode AND cathode, he would be happy. At the time, I didn't think much about it, but I've come to realize that is a big ask, especially to identify the ACME cell on a single piece of metal.

Thank heaven for that diagram up top (and that I'll repeat here)...

Source - I already told you up top, but since you asked so nicely... https://chem.libretexts.org/Bookshelves/General_Chemistry/Map%3A_Chemistry_-_The_Central_Science_(Brown_et_al.)/20%3A_Electrochemistry/20.8%3A_Corrosion

The ACME cell is still present these on a single piece of iron...

• anode - the bit of iron on the left, for some reason - a crystal defect, a difference in concentration in the electrolyte solution - that site is slightly more likely to release electrons
• cathode - a different part of the iron piece, the part on the right in this diagram
• metal - the two areas of the iron are connected because they're the same piece
• electrolyte - the metal has to be wet with some ions present (keep the metal totally dry, and you prevent corrosion)

At the anode, the iron becomes iron +2...at the cathode, O₂ becomes water (it helps if the solution is slightly acidic)...in between, we have iron ions and oxygen atoms, so we get iron (III) oxide...rust.

See, clear as day, huh?

Hiding a Nobel Prize From the Nazis

This is famous - at least within the science teacher world - story about the hiding of a couple of Nobel prizes (gold medals) won by Jewish scientists by Neils Bohr. 

I've posted the story (from NPR's quoting from The Disappearing Spoon) before, but this goes into the science of the full electron shells (particularly the d-shell) and equilibrium going on a lot more than that other article did.

Yemen's Deadly Ghost Ship

I just read an article about the FSO Safer, an oil tanker that has been taken out of service as a ship and converted into floating storage off the coast of Yemen. Apparently, according to OpenDemocracy, anyway, that's a bad thing. (All of the below quotes and the above image are from that article.)

A victim of Yemen’s current civil war, the Safer has fallen in to a dire state of disrepair, with rust spreading around her hull and on-board equipment. She is packed with more than a million barrels of crude oil, which over time is thought to have steadily released flammable gases meaning the Safer could explode if she doesn’t simply begin leaking huge volumes of oil into the sea.

Well, as long as there's a way to avoid an explosion. All we have to do is leak the three MILLION barrels of oil into the ocean.

That's a fair trade, right?

But it gets worse. The 1.15m barrels of oil on board is Marib Light, a type of crude that mixes more easily with water, explains Dr David Soud at IR Consilium, a maritime security consultancy that has been tracking the FSO Safer situation. 

Should that oil begin to flow out of the rusting hull and into the Red Sea, it could form a spill roughly four times as large as the Exxon Valdez spill in 1989 – and with crude that mixes down into the water column. 

... 

That means the Safer presents a significant threat to nearby coral reefs, marine life and also desalination plants in the region that provide drinking water to nearby countries including Saudi Arabia.

Ah, so apparently leaking three million gallons of light crude oil into the ocean would be bad.

But what's the problem with just leaving the tanker in place? It's not like an unmaintained metal tanker in a salty ocean is going to be a problem, is it?

A victim of Yemen’s current civil war, the Safer has fallen in to a dire state of disrepair, with rust spreading around her hull and on-board equipment.

...

Sitting in the sea, it is corroding away rapidly as we speak.

Since civil war broke out, little or no maintenance has been carried out.

...

“Any kind of ship that sits in the sea or moves around in the sea has to be regularly maintained,” says Laleh Khalili, professor of international politics at Queen Mary University London.

...

In the absence of constant sanding and painting of the hull, the Safer has essentially been left to rot.

...

Plus, the Red Sea is a particularly salty body of water, meaning that the Safer’s hull is corroding faster than it would elsewhere in the world.

...

A giant problem begging to be fixed – waiting, rusting, creaking

Oh, that's right. Steel in salt water is going to corrode quickly and disastrously.

Honestly, though, I don't understand the idea that the tanker was simply, "converted into a stationary storage facility for the Safer oil company and brought to an offshore position near the Yemeni coast".

That's weird, but I guess it's not really different from rolling storage.

Corrosionpedia

Corrosionpedia isn't a wiki (that would mean that the website and its information was editable to anyone in the website's community), but it is along the lines of a corrosion encyclopedia - with the words just mushed together.

The site has a huge amount of corrosion-related content, and I've particularly enjoyed the industry news section - a weekly collection of one-paragraph summaries of corrosion in the news with links to more in-depth articles about the story. Some of the stories are in very industry-specific publications, but others are in more popular media. No matter what level your students are, you should be able to find some corrosion-relevant current events with minimal searching.

Much of the rest of the website, however, is internally-written articles on specific corrosion topics. A quick survey of those finds articles on "corrosion control considerations in the equipment design process", "what new materials science studies suggest about corrosion control in the future", and "an intro to pipeline corrosion and coatings". The articles are written on a level that people - students, teachers, even non-education folks - should be able to get much of the content, and the articles have a number of links internal to corrosionpedia if you want to know a little more. The articles are broken up by topic - "cathodic protection", "materials selection", and others.

They also have webinars - some of which are free, all of which require creating an account; downloads - whitepapers, reports, slide presentations; Q&A - single questions with answers from "corrosion experts"; a directory of corrosion-focused companies; and an events calendar of upcoming (and recently past) corrosion industry events.

I've found the articles and news story collections useful. I haven't found the other sections useful...yet.

So, take a look at corrosionpedia and see if you can figure out why a gas station canopy collapsed, why a pedestrian was injured by a streetlight pole, or why a bridge in Mumbai, India collapsed.

You know, in case you couldn't guess from the website's name.

This ain't crazepedia.

A bad corrosion graphic?

In recently searching for sacrificial images online, I came upon the following graphic (at opentextbc.ca)...

...and I think it has a pretty significant error in representing the science of how sacrificial protection from corrosion works.

I'll put my reasoning after the jump...

Sacrificial anode photos and links

I was recently searching online for some better images of sacrificial anodes for our material science slideshow at school, and I thought I might as well put these out there for any other science teachers using the blog.

I will say in advance that I didn't take any of these, and that's why I'll be linking to the source. All were accessed in January and February of 2020. The links may rot, but I'll keep the images up.

What is an anode rod & how does it work?

I know the answer.

Do you?

If you don't, you might want to check out Landmark Home Warranty's great webpage explaining the usefulness of and science behind hot water heater anode rods.

There's even an infographic in case you don't like so many words.

DoD Corrosion Prevention Podcast

So much needless special effects and multiplication of the speaker. - and motion that does more to distract from that focus us on the message. This video just screams 90's to me even though it was clearly produced in the 2000s.

I had no idea that we had a director of corrosion policy and oversight (corrdefense).

The most useful part of this video might be in the distracting animation of the 12 types of corrosion that rotate at the top of the video.

And I'm not sure I'd call this video a podcast.

The Importance of Corrosion Prevention & Reinforcing Our Nation's Infrasctructure

Not really a surprise that painters want us to know that bridges and infrastructure can corrode. It's like they might have some sort of financial interest.

I don't know that they had to go to the efforts to photoshop out the bridges in the intro, however. That's a little creepy looking.

There's a really nice animation at 1:10 showing the anode and cathodes forming on the same piece of iron, then they mostly go into showing how we can prevent (or at least minimize) corrosion via inspection and maintenance (mostly through painting - I'm sorry - through 'coating appli[cation] by certified coating application specialists on a regular maintenance schedule')

Corrosion in Motion Golden Gate Bridge

Doncha just love student project videos?

At least it looks like these kids might actually have been at the Golden Gate Bridge for some of their filming. And while their special effects aren't exactly on a professional level just yet, they gave the monster attacks, earthquakes, and explosions a good, college (or high school) try.

They do a decent job explaining why the iron oxidizes, including a pretty thorough writing of the chemical reaction of the rusting of iron. They also show a cross-section of what galvanizing layers look like and what reactions work within the galvanizing.

The video does end a bit abruptly, but it's not a bad effort. I'd be impressed if my students produced this video. Maybe this'll be something to work toward for next year.