Stainless steel passivating polish?

[jhulmer]

Originally Posted by IMACSS

Polishing Stainless Steel (SS) is dear to my heart as I have had a few attempts but not sure of the value of my input here. Here goes as I have taken notes of the great suggestions on this thread so far:







(1) Firstly (CAUTION) - I use a product called Avesta Pickling paste after welding SS which I understand has some passivation properties. It comes as a blue/green/red/clear gel that can be painted on as well as a spray.

Please note that this product should be used with caution as it contains Sulphuric, Nitric and Hydrofluoric acids which have some terrible outcomes through contact with skin, eyes, mouth and inhalation etc. It is also not environmentally friendly BUT is water soluble at least.

Pros - It works and it needs very little quantity etc
Cons - Please read notes above, I would not like to store it on my boat and PPE is definitely required. Possible expensive as well.



(2) After using the pickling paste and as a cleaning agent I use a metal polish called Autosol. LINK to the MSDS/SDS http://autosol.com.au/wp-content/uploads/2014/07/msds_autosol_1000.pdf (copy and paste ??)

Autosol is found in most auto shops etc and is non-hazardous and not a dangerous goods and comes as both a liquid and a fine paste. It is easy to apply and remove and appears to apply a thin film to protect the surface (for a while at least)

Pros - It works, easy to apply and I do have some on my boat
Cons - A little expensive and needs to be reapplied occasionally



Thanks heaps for the discussion and hope I've added some value.

We also fabricate stainless and have used something very similar to what you have posted here. This is a very effective fast working gel that gets the job done quick. But it is necessary as you point out to be very diligent in the application and cleanup. However, I don't consider it a bad product to work with if you use precautions.

You can buy it here:
https://www.mcmaster.com/#pickling-paste/=1dqltb9

And here are the MSDS sheets:

[Blaine]

Hi All,

I've yet to try these but I have ordered the Quick Silver.

https://www.auroramarine.com/store/quick-silver.html
https://www.auroramarine.com/store/s...ss-shield.html

The oxalic acid can damage varnish, so as mentioned, a very thorough rinse / washdown is necessary after use.

[Wotname]

Originally Posted by Ecos

Sika Concrete Etch. It's ok to love being wrong.

Good to know - both sentences.

[model 10]

Well the concrete etch is expensive so it's not very good info, but in the USA, Cascade Dishwashing gel has nitric acid in it too.

[leftbrainstuff]

Originally Posted by 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?

Stainless (3xx) and aluminum naturally form a protective oxide layer. It's the grit, dust, brake dust, etc that creates the spotting.

Once stainless is polished regular rinse or wipe will maintain the finish.

[lateral]

I've used pickling paste from my tig kit which tends to dull SS off if you leave it on too long and dilute oxalic. Prefer the oxalic.
The other half bought a powdered general cleaner which was good, but required rubbing.
Also used the pickling paste on hard growth on the rib. That worked well.
Of course well shy of the ocean.
I thought proper passivation require electropolishing?

[lordgeoff]

Originally Posted by 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.

Phosphoric acid is the go. Can get it fairly easily in chandlerys. In Turkey it is called rust remover but phosphoric acid is the active ingredient. Use gloves wipe on your stainless and follow up up a few minutes later with a sponge and fresh water.

[DO335]

I saw "Super Stainless" on the Tides Marine page. I haven't used it so have no idea how well it works.
https://www.tidesmarine.com/super_st..._stainless.php

[Coltrek]

<<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.>>


This fellow has his finger on it. I can speak with some authority on this subject, as it has been my business for the last 45 years.
Commercial Citric acid passivation solutions are accepted by certain Mil-Spec regulations, but it won't remove weld burn, or heavy corrosion. For this you need the Nitric-5 solution, which is basically one part Hydrofluoric Acid, 8 parts Nitric Acid, 20 parts water. This is not for children, as Hydrofluoric is incredibly strong and will eat holes in your hand very quickly. Nitric by itself will remove some iron/rust from the surface, but not like this. Of course, this may all be academic, B/C Hydrofluoric is hard to access. Also, warming the parts up some really speeds up the process, by this I mean no more than 200 degrees, as heating SS can ruin it. Also the heat really makes the solution fume, so keep your nose away.

[Flyingriki]

Seems like many have just posted what they think is good SS polish or cleaning without answering the OP question.
I had the same question and seem to have found that it can't be done in one step as I had once asked. Need to clean the SS. Then need to re-passivate the SS, then need to coat it with a protective wax.
So I use barkeepers friend or other cleaner. Then I further polish it with some metal polish. then 'Something Stainless' (forgot the name) to re-passivate and finally Collinite wax.
Wonder if the polish prevents the passivation? Sure looks nice!

[hellosailor]

griki-
There's an inherent contradiction in caring for stainless. In order to remove visible rust, you need to attack it, either chemically (all the acids) or mechanically (Flitz or other simple abrasives). But that would leave bare stainless and more unseen iron grains, so it would rust again. Unless you apply a polish or wax to prevent further *rust* blooms.
The problem is, that blocks oxygen and without oxygen apparently stainless is susceptible to other issues, like crevice corrosion in the presence of water without oxygen.
So the compromise is, clean it as best you can (Flitz and a number of other old time combination abrasive polish (Bentonite, aka Fuller's earth, aka diatomaceous earth) waxes dp the job of removing surface rust and applying a 'wax' in the same operation, and that seems to be about all you can do, other than having the stainless pulled and really properly passivated.
Or, I suppose, you could just have it sandblasted and then powder coated.(G)

[ngmayo]

[QUOTE=a64pilot;2673635]

Originally Posted by Ecos

Storing nitric acid on a boat is problematic, worse than acetone.

I've used acetone recently on stainless rails. Seemed to work well. I didn't know of the dangers of storing acetone onboard what are they?

[lordgeoff]

Originally Posted by skipmac

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 ????

Phosphoric acid?
ONTACT Mr Stoddart .........

[schaf]

I have found that good old Turtle Wax both removes and protects I also use a sonic vibrating brush to clean works very well at 3500 strokes per min.

[model 10]

I've tried citric acid. I soaked hardware and small parts in a warm bath of 1lb of citric acid to 1/2gal of water. It works better than anything else I've tried to remove light rust and slow down more rust. I try and use it as a spray but it evaporates too fast and burns your fingers when you scrub.