Homemade Evaporust Alternative

[JHCC]

I chanced across the following video from a YouTuber in Italy who has come up with a very interesting homebrew alternative to Evaporust. I have not yet tried it myself, but his explanation and analysis are very compelling. (NB: According to the YouTuber’s Patreon page, his name is Carlo, and he is a forensic expert witness in ballistics and mechanics. His main YouTube channel is devoted to firearms restoration. In the intro to this video, he also describes himself as "a wannabe chemist". On the face of it, I’d say he's a pretty good one, and I’m guessing that his background as an expert witness contributes to the clarity and precision of his presentation.)

The short version is that to one liter of water, he adds 100 grams of citric acid powder and 40 grams of sodium carbonate (washing soda)*. After the foaming subsides, he adds a dollop of dishwashing liquid.

The chemistry of this process is that the sodium carbonate and citric acid react to form sodium citrate, which chelates the iron oxides in rust, removing them from the surface of the metal and allowing them to be flushed away by the water. The dishwashing liquid acts as a surfactant. He suspects that this is how Evaporust works, although he acknowledges that its composition is a trade secret. Unlike acidic rust removal (muriatic acid, vinegar, etc), this has little effect on the base metal — as he notes, about 1/4 the thickness of a standard layer of gun bluing. 

Carlo estimates that his solution costs about a tenth of what you’d pay for an equal volume of Evaporust and will remove about three times as much rust in a shorter amount of time. As he says, “Not bad for a greenhorn.”

 While this is presented as a rust removal technique, I’m interested to see if it would also work for removing forge scale. I’ll give that a try soon, and I’ll report back on the results  

 
* Carlo notes that you could also use either 63 grams of sodium bicarbonate (baking soda) or 30 grams of sodium hydroxide (lye).

[Daswulf]

Thanks for sharing this John. I would like to give this a try as well. 

[Frosty]

Dang I had to sign back up with youtube and sit through a BUNCH of full screen ads to watch!

I might have to give his recipe a try and compare it to my favorite rust juice, about 10% phosphoric acid and a drop or two of Dawn dish soap. I have to admit Dawn isn't much good since the phosphates were removed, it hardly cuts grease and makes a poor surfacant.

Thanks for the link John.

Frosty The Lucky.

[Buzzkill]

Just FYI, if you use DuckDuckGo's browser, they have their own video player.  It gets rid of all of the ads on YouTube, and also removes the comments and suggested videos.  However, there are some videos it will not play due to some form of copyright issues.  Without ad blockers/removers YT is unusable for me.  If they ever get to the point where I can't block most of the ads that will be the point I cease using the platform.

This formula does look promising.  It goes on my list of things to try when I get a chance.

[Frosty]

That works if you can read an URL or reasonably definitive title and the LOGO for the person's site, channel, etc. They weren't readable and were locked out if I try viewing it on YT. YT has gotten worse about locking videos to their viewer. 

Adblock notifies you of ads they block and when I try viewing this one of Duck duck go the notifications stack up the right side of my monitor, sometimes so many ads the cascade flows like a bad movie and you can't shut the notifications off! That is some bright boy's idea to show us how good a job they're doing and is as irritating as the ads! Grrrr.

Frosty The Lucky.

[JHCC]

I tried copying the link from the above post and pasting that into DDG. It opened the video in their "Duck Player" and played it with no ads at all.

Maybe you can try finding videos in the regular YouTube and then copying their links over into DDG for easier playing.

Either way, I need to borrow Lisa's postal scale from the yarn shop to weigh out 100g of citric acid and 40g of washing soda.

[Frosty]

I managed to find a work around to play YT videos on DDG but it's really working my adblocker overtime. 

Frosty The Lucky.

[JHCC]

First experiments. 

Here’s an old try square that sat half-in, half-out of the bath for about twenty minutes. Good initial result on the blade; probably would have been better if I’d given it Carlo’s half hour. The stock shows the untreated surface.

I’m particularly interested in whether or not this will take care of forge scale. Here are a couple of the tap handles with both black scale and red rust:

So far, not much result on the scale, although the rust came off fine. 

So, I’ll leave them to soak overnight, and we’ll see how things go. 

[JHCC]

Update, a couple of hours later. Some of the thinner scale has dissolved away, but the thicker scale is still hanging on. 

I’m looking forward to seeing how it is tomorrow. 

[JHCC]

Second update: the dog needed walking at 1AM, so I took advantage of the opportunity to check on the progress. The solution is definitely dissolving scale as observed before, with most of the lighter scale scrubbing off with a toothbrush. The heavier scale is still pretty stubborn, with much of it resisting both the toothbrush and a regular wire brush. 

[Buzzkill]

I'm waiting for updates with interest.  Vinegar works, but I'd prefer this solution (both meanings) if it is suitable for the task.

[JHCC]

Morning report: after an overnight soak, a lot of the scale had loosened to the point that I could scrub it off with a toothbrush. Some of the more stubborn bits of scale yielded to a wire brush, and some of the heaviest bits are still clinging determinedly. 

This latter one is almost entirely clean. As a reminder, here’s what it looked like before:

I’ll give another update this evening, but I'm starting to think that anything longer than a 24 hour soak is overkill, maybe even 2 or 3. I may also touch one of these to the knotted wire brush on the grinder, to see how it responds to that.

[JHCC]

Update: a 24-hour soak seems to have done its work reasonably well. 

[Hefty]

Is this the sort of solution you can keep and re-use, or does it need to be made fresh each time? (Sorry, I can't watch the video currently, at work).

Cheers,

Jono.

 

Nevermind, I muted it and put on the captions.

This looks really promising. Thanks for the link and your additional testing, JHCC!

[JHCC]

You’re welcome! At the moment, I’ve been looking at how it is at removing scale rather than removing rust. 

For the former, it’s not bad but not perfect.

For the latter, the initial results seem fine, but further testing is needed. Let me see if I’ve got a heavily rusted hammer head or something around here…