Rust removal from blades - experiments

[Bill_S]

Because of a recent thread, I became curious about which common household product could do the best job removing rust. I tried three non-abrasive products - Lime-A-Way, Bar Keepers Friend, and Naval Jelly. There was one clear winner - Bar Keeper's Friend.



Bar Keeper's Friend is a non-abrasive powder meant for cleaning metal cookware. The active ingredient is oxalic acid. This acid is naturally present in bitter greens, i.e. rhubarb contains it.

The other two products are in liquid form, and are more dangerous to handle. Lime-A-Way contains sulfamic acid, and Naval Jelly contains phosphoric acid as active ingredients.


The Experiments

I started with an old pair of skates stored in my basement. The rust was a bit more than just surface rust, and had slightly pitted the hollows of both blades. The rust followed the pattern of the hard guard in which they were stored, and areas of contact rusted. Here's a shot of one of the blades used for testing before application of any treatment...


One of the untreated blades showing rust

(sorry for the slightly fuzzy picture - this was a rush job!)

The Naval Jelly is a product for removing rust in marine and automotive uses. I dipped a Q-Tip into the thick liquid, and applied it directly to a couple of the rust areas. After application, I waited 5 or so minutes per instructions, then wiped it off. While it was an improvement, it didn't remove some of the rust, but more worrisome, it left a dark stain where it had been in contact with the metal.


Naval Jelly treatment.

Next I tried the Lime-A-Way. I wetted the Q-Tip with it, and rubbed for about a minute over an area of rust. The rust clearly was transferred to the Q-Tip, but the result still wasn't as good as the Bar Keepers Friend described next.


Lime-A-Way treatment

The last product, Bar Keeper's Friend was applied using a damp Q-Tip to which the powder was applied. I did about a minute of vigorous rubbing on a couple of rust spots. Even the spot that remained after using Lime-A-Way was subsequently improved by using Bar Keeper's Friend. It took care of fresh spots quickly too, and left the best finish.


Bar Keeper's Friend treatment

By feel, it left the smoothest surface. I had feared some minor pitting would remain, and it did, but the BKF treatment left the smoothest surface of the three products tested.

It was a clear win for Bar Keepers Friend.

Of course a good sharpening would beat any of these products, but there are times when this may come in handy.

[AgnesNitt]

I use a gummi stone. I suspect a jeweler's emery would work as well.

[Query]

BTW, Bar Keeper's friend is abrasive.

https://www.barkeepersfriend.com/cleaning-products/cleanser-polish says

Ingredients

mineral abrasive, oxalic acid, surfactant, water-softening agent

Interestingly enough it only says to use it on stainless steel. It doesn't explicitly mention non-stainless steel.

I have used it on stainless steel cookware. Much better than Ajax and Comet, because they have a larger grain size, which leaves obvious scratches, that bacteria could get into. It's great stuff for removing stains and slight burns from stainless steel from pots and pans.

Be careful not to rub or scrape at the edges, if you can - I think anything like this could dull them a bit.

Did you try vinegar? As a mild acid, it does react with rust, and remove the oxygen, to an extent. But, because it isn't an abrasive, it may not leave a smooth surface, so at least on cookware, I like Bar Keeper's friend better.

[fsk8r]

Glad to hear Barkeepers friend works. I'm currently trying to hunt for some.
I've had a brand new set of blades which have gone very rusty after only a couple of hours skating and then some long storage.

My own experiments have been with citric acid and cream of tartar (tartaric acid for the chemists). This mix has taken a lot of rust off, but not finished the job. Adding a little hydrogen peroxide has also helped the rust removal.

Vinegar would probably work, but the barkeepers friend has a stronger acid so is likely to work better.
I'm currently debating using some limescale remover as that should be a strong acid, but I'm not sure about it's concentration.

[Query]

Try Walmart, or many grocery and hardware places. It's very common.

The manufacturer website has a "where to buy" link.

[Bill_S]

Query: Thanks for pointing out that Bar Keepers Friend contains mild abrasive. The term "polish" on the front of the can hints at that. It is a very mild abrasive as you describe, and I use it everyday on my cookware without abrasive scratches forming. It's good stuff.

Going further, I remembered that some of the woodworking forums that I frequent discuss rehabbing old, rusty tools. Some of them are career restorers who bring back to life some really rusty basket-cases.

They praise liquid Evapo-Rust as a good overnight soaking treatment to remove rust. The MDS sheet doesn't reveal the active ingredient (must not be toxic - good!). Further searching found that it could be  ethylenediaminetetraacetate or EDTA.

I wish that I had some Evapo-Rust on hand to try. It sounds promising, but because a long soak is suggested, either the blades would have to sit in a shallow dish, or removed from the boots for treatment. Either is easy enough to do though.

[sampaguita]

I used petroleum jelly with a Scotch Brite scouring pad to remove a very thick layer of rust from my old skates. It worked rather well, but I had to be careful not to dull the actual edges. It was manageable.

Using oxalic acid is interesting. Would you know what concentration BKF uses?

[Bill_S]

The MDS sheet lists the Oxalic acid at 7.5 to 9.5% by weight.

There are two other ingredients listed, Feldspar (% is proprietary, and I suspect that this is the mild polishing agent), and Linear Sodium Dodecyl Benzene Sulfonate (DDBSA) -  essentially detergent.

[tstop4me]

If there's moderate to heavy rust on skate blades, you'll want to remove the rust before you have them resharpened so the rust doesn't foul the grinding wheel; and a clean, uniform initial surface will make it easier to achieve uniform edges.  A careful sharpener will probably remove the rust first anyway, but he may charge you extra.  Since you'll probably want them resharpened, however, I don't see the need to be super-meticulous about abrasives in the rust remover, as long as they are not too coarse, and potential dulling of the edges. 

If it's just superficial staining, then, as Bill mentioned, it'll probably be gone in the course of a session or so anyway, without any deliberate rust removal action.

[tstop4me]

I used petroleum jelly with a Scotch Brite scouring pad to remove a very thick layer of rust from my old skates. It worked rather well, but I had to be careful not to dull the actual edges. It was manageable.

I tend to stay away from acid-based rust removers, and use a method similar to yours for general purpose rust removal.  Except I use Liquid Wrench Penetrating Oil, instead of petroleum jelly, with Scotch Brite.

[tstop4me]

//entered in error; can't delete//

[lutefisk]

Query: Thanks for pointing out that Bar Keepers Friend contains mild abrasive. The term "polish" on the front of the can hints at that. It is a very mild abrasive as you describe, and I use it everyday on my cookware without abrasive scratches forming. It's good stuff.

Going further, I remembered that some of the woodworking forums that I frequent discuss rehabbing old, rusty tools. Some of them are career restorers who bring back to life some really rusty basket-cases.

They praise liquid Evapo-Rust as a good overnight soaking treatment to remove rust. The MDS sheet doesn't reveal the active ingredient (must not be toxic - good!). Further searching found that it could be  ethylenediaminetetraacetate or EDTA.

I wish that I had some Evapo-Rust on hand to try. It sounds promising, but because a long soak is suggested, either the blades would have to sit in a shallow dish, or removed from the boots for treatment. Either is easy enough to do though.


I've bought Evapo-rust at Auto Zone stores.  Some stock it, others don't.  One can check with the company's website to find a place to purchase the stuff.  In my experience, Evapo-rust works well on ferrous items that you can submerge in a plastic tuperware style tray of the stuff and lock a cover on to limit evaporation.  Be aware that the process tends to make the rusty areas change color.  Since Evapo-rust works via chelation, it removes a tiny bit of iron from the rusted (iron oxide) areas rather than converting the iron oxide to iron phosphate as is the case of most other products.  So at bit of polishing with a mild abrasive might be in order apres treatment.  (Aside:  toothpaste contains a very mild abrasive).   Also, after treatment with Evapo-rust and the polish of choice, one should probably take steps to prevent further rusting--which could start as soon as the Evapo-rust is washed away.  In most cases of rust abatement this means painting the metal object with a protective coating.  In the case of skate blades this is probably not the most desirable option, although there may be a clear coat that could be applied.  In theory Evapo-rust should work on skate blades.  I've used it to de-rust small auto parts and rusty tools which were small enough to submerge for a couple days in a plastic tub.  It works well.

[Kaitsu]

Bill, have you seen this?

https://www.barkeepersfriend.com/how-to-clean-ice-skating-blades/

[supersharp]

That's great!  Bill has found his new retirement hobby...product endorsements!

[Bill_S]

Hooray, it's my 15 minutes of fame!   

[tstop4me]

Bill, if the company were really decent, they would send you a complimentary case!  I'm surprised though that they consider the rusty/corroded/tarnished ice skate market to be big enough to warrant a dedicated article.

[Isk8NYC]

Bill, have you seen this?

https://www.barkeepersfriend.com/how-to-clean-ice-skating-blades/

Bravo, Bill deserves a lifetime supply for endorsing the product!  I've always thought that the tech crew here could write articles about skates and blades to make some $$$!

I'm not really a "numbers person," but I do look at the forum stats occasionally.  It's amazing how random web pages linking to SF leads to big jumps in the number of page views.  Agnes Nitt once posted something on her blog that linked to us and the numbers soared for a few days.

[Kaitsu]

Another way to remove rust from the blades... https://youtu.be/aX_Iv-k4Ak4

[Query]

Another way to remove rust from the blades... https://youtu.be/aX_Iv-k4Ak4

There a a significant number of scratches on the side of the blade when the person is done. So maybe it is a coarser abrasive than Bar Keeper Friend?

The person abrades the whole side of the blade. So they are gradually removing the chrome (?) plating that helps prevent future rust. Those scratches tell me they are removing a fair bit of metal. Perhaps it would be better, to only abrade the bottom "chrome relief region", where is no plating?

I wonder if using a coarse abrasive like that could alter the thickness profile of the bottom of the blade in a non-uniform manner, sufficiently to affect skating.

On the plus side, if you wanted to play with parabolic or tapered side honing on currently parallel sided blades, it might be a fairly fast way to create it.

Also, I have a somewhat rusted pot (a building contractor where I used to live left water in it overnight without asking), that ordinary treatments can't fix. Maybe the coarser abrasive (followed by Bar Keeper Friend to make it smooth again) would do the job - but so might sandpaper.

Of course, I'm sure we all agree that rust prevention is better than rust removal. But prevention is a separate topic, which has been covered many times in these forums.

[supersharp]

There a a significant number of scratches on the side of the blade when the person is done. So maybe it is a coarser abrasive than Bar Keeper Friend?

The person abrades the whole side of the blade. So they are gradually removing the chrome (?) plating that helps prevent future rust. Those scratches tell me they are removing a fair bit of metal. Perhaps it would be better, to only abrade the bottom "chrome relief region", where is no plating?

I disagree about the scratches--if you look at the view before and after polishing off the rust, the same scratches are present on the blade before it is given the rust removal treatment. 

[tstop4me]

I wonder if using a coarse abrasive like that could alter the thickness profile of the bottom of the blade in a non-uniform manner, sufficiently to affect skating.

On the plus side, if you wanted to play with parabolic or tapered side honing on currently parallel sided blades, it might be a fairly fast way to create it.

The product in the video is called Universal Stone.  Strange that the video didn't explicitly call it out.  But I did a freeze frame when the container was shown.  I couldn't find details of its composition; but it doesn't appear to be an intentionally coarse abrasive. 

But why use this product to modify the blade thickness profile in your proposed scheme?  Just as you can buy abrasive papers and whetstones with different degrees of graded coarseness, you can also buy loose abrasive powders with different degrees of graded coarseness.  Mix them with the base of your choice to create a slurry or paste.

The $60K question:  How do you plan to control the blade thickness profile in your proposed scheme?

[tstop4me]

I disagree about the scratches--if you look at the view before and after polishing off the rust, the same scratches are present on the blade before it is given the rust removal treatment.

Yeah. The blade looked like it was mildly, rather than heavily, rusted.  From the timestamps on the video, it took nearly 90 sec of vigorous scrubbing (not including the wiping after the scrubbing) to get rid of the rust.  So the abrasive couldn't have been too coarse.

[Query]

I disagree about the scratches--if you look at the view before and after polishing off the rust, the same scratches are present on the blade before it is given the rust removal treatment.

Oh - I did the wrong freeze frames. Some of the scratches appear at some angles, but not others. So this is another case where tiny, tiny changes in lighting and viewing angle can radically change what you see... What a nuisance.

>tstop4me wrote
The $60K question:  How do you plan to control the blade thickness profile in your proposed scheme?

I don't plan to do this. I don't personally believe there is much difference (at my low skating level) between parallel and other side honings - except possibly dovetail cut, which would be really difficult to produce this way, but which alters the included angle of the edge. Though there are people who claim the difference between different forms of side honing is significant.

At my skating level, I probably couldn't test the effects in a meaningful way, because the precise way I skate isn't consistent enough to perform well enough controlled experiments to eliminate placebo effects, or my personal prejudices about whether the difference is significant. E.g., some people have claimed that some forms of side honing create longer and/or faster glides - but I'm not good enough to keep my how deep my edge is perfectly consistent between two trials - and the ice might change roughness or temperature in the intervening time. Again, some people have claimed that some forms of side honing make it easier to turn and or land a jump - but once again my technique isn't consistent enough to perform well controlled experiments. I suspect the time I would waste on the experiment would be better spent practicing skating, or doing something else fun.

I have always found it interesting that some people have claimed you can skate faster if the blade is tapered thicker up front (sort of like a rain drop), and some people have claimed it is better if it is thinner up front. That is one of the reasons I have been skeptical of claims about side honing.

Likewise, one very experienced coach told me that parabolic side honing helped her daughter land jumps. But it was the opposite for her. I wondered if the other poorly controlled factors in blade shape might have produced that differences in performance.

If one did want to try side honing, I suppose one could take a micrometer and measure the thickness at many points, and iteratively try to achieve a given thickness profile with the abrasive slurry. I admit that that would be slow and clumsy, but it wouldn't require any tools I don't have. But maybe some form of sandpaper would be better - because one could apply it to a very thin layer at the bottom of the blade, and abandon that layer if one didn't like it.

At a guess, there are probably machine shop tools which can do side honing faster and perhaps better. I don't know what commercial blade makers use. But good machine shop tools are very expensive. Not something your average skater is likely to buy.

Maybe side honing could be imposed by some of you with powered sharpening machines - sort of a machine shop tool, but one that several of you have already bought - if you made or bought a guide - somewhat like a rocker bar, but of course with much less curvature. I'm not experienced enough with such machines to how that would work, and how you would mount the skate blade at the correct angle to use it without the rest of the skate or blade getting in the way, but perhaps one of you could figure out a way.

I wonder if this abrasive is significantly different in application or effect from Bar Keepers Friend. 

I haven't had much if any call to remove rust from the particular stainless steel alloy my current blades are made from, because I try to take good care of them. Except when I had flood damage - but there was so much rust on those blades that nothing could have saved them.

[supersharp]

Our rink opens in a few days, so my guess is I will start to see a pile of blades that have varying degrees of rust on them. 
 
"I have no idea how this happened, she is always so careful" will be the comment from the parents.  What I have observed is that on the last day of skating, there is a lot of social interaction happening as people take off their skates and realize they won't see some of their skating friends for months, and there is less attention paid to the blades.  Same thing happens after a show or a test session.  Most skaters do not go home and coat their blades with vaseline or wax to protect them during the months off the ice.  Some don't even take them out of their bag, which is part of why the boots stink (that could be a whole different thread--ways to overcome boot stench!). 

I'm always glad to see more tested options for relatively quick and successful rust removal, particularly because I can't always find Bar Keeper's Friend.  Some stores here have BonAmi, which is a very different formulation than BKF, but maybe is worth a try as a comparison product.

[Kaitsu]

The pink stuff paste seems to work also for rust when used in same way as Universal stone in the video, but it seems to be less abrasive.

Query,
I have challenge for you. Buy somewhere Universal Stone and try to polish the chrome layer away from some of your worn-out blades. When we hear you next time, we know that you have managed to remove chrome layer. It should not take so long if Universal Stone is so abrasive as you believe. When you are retired scientist, you have all day long for polishing. 

Brand was not mentioned in the video as intention was not promote any certain brand which is not possible easily available locally. Point was highlight that the clay is "secret" and you can try to find similar product from the local super market. Clay is used example in many washing machines washing powders, so even regular washing powder could work as well. Clay abrasive properties  is the reason why such a washing powders destroys (in long term use) also your washing machine water pump plastic bearing housing (which is water lubricated) and it gets noisy. Clay stones are used also clean / polish cars painting and in many other places. You can find plenty of information about the clay by Googling or from the Youtube.