Stainless steel passivating polish?

[hellosailor]

Maybe five years ago there was some discussion about a "new" product, a stainless steel polish that was also supposed to do some passivating to prevent future rust.

A brief search didn't turn it up, but I'm wondering if anyone remembers what the product is, and how that has worked out in the long term? Did it do the job of passivating iron grains and preventing ongoing rust?

[AiniA]

There is more than one product I think. I have used Wichinox which seems to work OK. All of them require that they be used in not too hot, not to sunny conditions which dry out the chemical before it can work. I have also tried citric acid directly (mixed with concentrated lemon juice). It is cheaper for sure but runny and messy.

[hellosailor]

Thanks. I was curious about the one I can't remember the name of, because it was supposed to be so much better than the usual products.

Citric acid, in many products, is the "environmentally friendly" alternative used industrially these days, as opposed to the older stronger acids. Citric, oxalic, phosphoric, all work to some extent.

[skipmac]

Originally Posted by hellosailor

Citric acid, in many products, is the "environmentally friendly" alternative used industrially these days, as opposed to the older stronger acids. Citric, oxalic, phosphoric, all work to some extent.

So have you actually tried the various acids or specifically citric? To what extent does it work; barely, slightly, almost, pretty well, good enough or ????

[Jim Cate]

Most of the acids will take rust/staining off quite well. The Wichinox worked well but was pretty expensive here in Oz... so I made up my own mixture: fine rubbing compound mixed with some oxalic acid. Seemed to work much the same as the Wichinox, but no direct comparison was made.

Jim

[Jim Cate]

Most of the acids will take rust/staining off quite well. The Wichinox worked well but was pretty expensive here in Oz... so I made up my own mixture: fine rubbing compound mixed with some oxalic acid. Seemed to work much the same as the Wichinox, but no direct comparison was made.

Jim

[model 10]

Citric acid doesn't work that well but it's more harmless. You need something to give it body or it just runs off and drys out. It's best for soaking hardware. Nitric acid is the one that kicks ass and doesn't harm the steel and cause even more corrosion. There are some concrete cleaners etc that have nitric acid.

You can loose a finger nail or something if start using this stuff without gloves.

[a64pilot]

Citric acid does work, and does work well.
You should avoid nitric acid, it’s pretty dangerous stuff, and how do you dispose of it?

Passivation is not a brush on and walk away thing unfortunately , there is a process that must be followed to achieve best results, like anything.
I know you won’t believe me, and of course I can link to a study that is trying to sell you citric acid, there are a lot of those, but perhaps you’ll believe these guys.
https://ntrs.nasa.gov/archive/nasa/c...0110001362.pdf

[Wotname]

Originally Posted by Jim Cate

Most of the acids will take rust/staining off quite well. The Wichinox worked well but was pretty expensive here in Oz... so I made up my own mixture: fine rubbing compound mixed with some oxalic acid. Seemed to work much the same as the Wichinox, but no direct comparison was made.

Jim

I like your approach - good tip

[HopCar]

Suncor Stainless sells a citric acid passivating fluid and also some polish and a coating.
I haven’t tried them.
https://www.suncorstainless.com/passivating-fluid

To remove rust stains from stainless I use hyrdofloric acid in the form of Whink Stain Remover. It is sold in grocery stores near the laundry soap. Works like magic. Don’t know if it passivates as well.

[a64pilot]

I think most any acid will passivate, just some better than others.
Passivation I believe in its simplest form is just acid eating any iron left on the surface of the metal, so you want an acid that aggressively “eats” iron.
Before Citric acid, to actually, really passivate it took nitric acid in concentrations that it’s likely difficult for us to purchase, and it’s dangerous, and real passivation requires a temp controlled tank of course.
So we aren’t really passivating, but it seems to me that cleaning off the stains with barkeepers friend and then heating a small quantity of water and dissolving as much citric acid as you can in it, then painting that on the lifelines etc., does seem to help.
Of course the barkeepers friend cleans off surface stains pretty easily, I avoid scotchbrite green pads cause that will scratch SS pretty badly, then you need to polish, and I don’t want to.

[model 10]

[QUOTE=a64pilot;, and how do you dispose of it?




Dilution is the solution. Mineral acids are not the problem. You wash it down the deck. It's made from fertilizer

[johnserr]

"Spotless Stainless" . My boat neighbor uses this and it works great

[a64pilot]

[QUOTE=Ecos;2673624][QUOTE=a64pilot;, and how do you dispose of it?




Dilution is the solution. Mineral acids are not the problem. You wash it down the deck. It's made from fertilizer[/QUOTE]



I understand but really was speaking to the quantity you have in the bottle. Storing nitric acid on a boat is problematic, worse than acetone.
Most if they find out that I pump antifreeze overboard are horrified, but in truth if diluted it’s not toxic, and it breaks down very fast.
Just don’t let a dog drink it when it’s a strong mix, cause undiluted it is toxic.

[tomrealest]

I use Woody Wax with good results. It is expensive but goes a long way.