Barkeeper's Friend powder - cheap rust remover

I hadn't heard of using it as a 'soak' for rusty parts. But I have used cleansing powders to polish really bad chrome. However only for the old fashion chrome that was much more robust than the later stuff - it will scratch up the lesser quality/newer chromes.

A comment was made in the reference that the active ingredient in BarKeeper's Friend is oxalic acid. A old recipe for cleaning out the cooling system (radiator flush) is to use oxalic acid. Actually that is what the better rad flushes used to be, before the EPA got involved. Remember those old DuPont powder flushes with two-part containers; one the flush and the other the neutralizer? Does a great job of cleaning not only the rad but also the walls in the block, especially a cast iron one where rust builds up on them. So it makes sense BarKeeper's Friend might work as a soak. Oxalic acid is also commonly known as wood bleach. In areas where wood decks get a dark blackish stain from the environment it strips it back to new looking. You can buy straight oxalic acid online, but it will be MUCH stronger than the cleansing power so use with caution and protection.
 
Oh, wow, that is an interesting chemistry connection ! Oxalic acid (aka “wood bleach”) has been a staple in my workshop for a number of years as a dip (mix acid & water to taste) for old bicycle Parts with rust/compromised chrome. In fact some people mix it in tubs to dip complete Bike frames when restoring (personally, I’ve always just steered towards frames with better paint). Anyway, using the same product as a cooling system flush sounds like it would make great sense.
 
If we are talking about removal of real rust, I've found nothing better than phosphoric acid. A big benefit is it also converts the bare metal in the process, leaving a phosphite coating that protects it from further rust. And you can add a finish over the phosphite layer.


Oxalic acid (aka “wood bleach”) has been a staple in my workshop for a number of years as a dip (mix acid & water to taste) for old bicycle Parts with rust/compromised chrome.
Oxalic acid is very mild, so it makes sense that it is better from more delicate finishes, like chrome. Chris, what ratio do you dilute it to?
 
Yknow, I’ve never been (or felt like I needed to be) overly scientific about it. Being a mild acid, it seemed like the mix was more about having the proper viscosity/coverage & intensity of acidic action is simply controlled by how long the part is exposed to the acid. Basically, the rusty surface would turn black, rust stains would be gone but then the part would need something to protect the surface (wax, paint, whatever...I had a really cool rat rod handlebar that was dipped a while, rinsed & then clear coated).


Come to think of it I have a 5 gallon bucket find the right in metric hardware that was flooded along with my 79 X19...I gave the bucket a white vinegar rinse that had remarkable results, but oxalic acid is the ultrasonic cleaner may be the ultimate ticket for that stuff.
 
I've tried all manor of cleaning solutions in my ultrasonic cleaner. Including some rather strong bases and acids. But not phosphoric acid, as I thought it would be too caustic (although it really isn't that strong). Oxalic acid however is mildier and might work well in it.

Be careful with rust remover products though. I had a bottle of commercial rust remover soak that was given to me by the makers of it (to try out and report my results, as part of some product testing/evaluation consulting I do at times). The label said not acidic, safe for all metals, won't harm your skin, items can be left soaking for days, only removes the rust and no damage to the substrate, etc. So I tried it on a lock according to the directions; a Fiat key cylinder for the rear trunk/engine cover lock levers on the door post. The lock was rusted frozen and I was hoping to loosen the rust enough to work it free and be able to use the lock (it matched the key for the sister locks on the car). After a couple hours soaking I checked on it. The solution was so murky I could not see the lock, so I poured it through a strainer into another container. All that was left were the tumbler pins. It had completely dissolved everything else. Don't trust the labels and trial test things of importance before letting them soak.

I've also tested a couple of other rust soak products with very poor results. After days of soaking they hardly touched the rust. But others work better, so it is a bit of trial and error.
 
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