Polishing Stainless Steel Chainplates

[Noreastern]

Finding it more involved then first expected. Any hints or advice would be very appreciated.

[svtrio]

depends on how "dirty" they are … that said, Flitz polish works well for me.

I had a SS project (a ss stove) that had rust stains, some corrosion specks, grease and I used a variety of cleaners: oven off, but messy (very good); oxalic acid & lots of water to flush (fair); Flitz (very good); and oil eater (fair).

I gave each product a try on different flat surfaces.

The least painless and most simple cleaner proved to be Flitz polish. Easy to apply, and gave very good results. Use a small amount of polish; while the product doesn't require much pressure to give good results, I found that removing it required lots of turning of the microfiber cloth. I spread the polish with a small polishing pad, and the ss surface was not scratched (no sos pads, etc. during long years of use).

I'll use Flitz from here on out.

Roger

[Nicholson58]

SS items not on the boat can be treated in a chemical bath. Electro-polish.

On the boat, I use a Home Depot abrasive block. It is rubbery like an eraser with abrasive compound in it. Use the finest of the three available grades.

[colemj]

If you use abrasives on highly polished stainless, the stainless will start to rust faster afterwards.

Mark

[Azul]

I tried about 8 different polishes and techniques that didn't work, everything I could find on the internet including home brew concoctions. The only thing that did work was 0000 artificial steel wool polishing pads (repeat artificial, not the real stuff which will put little rust particles everywhere) dipped in CRC rust prevention fluid. The rust comes right off and doesn't seem to ruin the surface and leaves a long lasting protective film.

CRC is great, it doesn't leave a residue when it dries as WD40 does. I have kept my saltwater fishing reels and outboard motors looking like new for decades with this product.

[mfsykes]

West Marine carries a product called Colonite. Tan colored cream/liquid. Goes on just like car wax. I wear a cotton glove on one hand for applying and use a microfiber cloth to buff/remove. I have found this product to be excellent at removing rust stains. As for other metals (i.e. bronze) or SS down below - Barkeeper's Friend is great and cheap at Dollar stores.

[Noreastern]

I should have been more specific. These are new never polished 316 stainless chain plates fresh from machine shop. The processes I have found googling requires using three different buffing pads and three different polishes. One says to start using 500-700 grit wet sanding.

[a64pilot]

Colonite is a wax, a very good wax in my opinion

For the chainplates, don't even try polishing yourself, send them off to be electropolished, you'll never get that finish yourself

[Noreastern]

DIY may not get the best results but need the boat bucks elsewhere. So I spent four hours sanding and buffing four mizzen (small) chain-plates where they go thru and above the deck. Very hard work with changing paper and arms are shot for the day from sanding but results are passable for us. Thinking of using belt sander and more powerful buffer for main (larger) chain-plates. I also appreciate polished stainless so much more...

[Pauls]

There are two parts to how to finish your parts.

Part one is getting the surface finish you want. You can do this by hand, with abrasives. Start coarse, work to fine. Something powered like a belt sander speeds up the process greatly. If you are doing this by hand definitely use wet or dry paper, and keep it fully wet (with water) while you work it. The abrasive cuts faster and does not load up the paper as much when used wet.

You can also take the parts to an electro polisher. Electro polishing is limited in how much material it is practical to remove, so ideally you should have a fairly decent finish on the parts before you give it to them. Electroplishing can give an excellent finish.

Part two is passivating. Any 300 series stainless should be passivated as a final step. (Actually I'm not sure if passivating is needed if you use electropolishing, but I guarantee you need it otherwise. Passivating reacts with the the free iron available on the surface of the stainless, rendering it passive so it won't rust later. There are passivating solutions and pastes commonly available, this is easy to DIY.

Good luck, Paul

[Nicholson58]

Originally Posted by Noreastern

I should have been more specific. These are new never polished 316 stainless chain plates fresh from machine shop. The processes I have found googling requires using three different buffing pads and three different polishes. One says to start using 500-700 grit wet sanding.

I did this exact job on my titanium plates. I only polished the part that shows above the deck.

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Start with 400 grit on a DA sander and work them over until shiny all over and no cutter marks. If there are deep machine marks start with 220. Progress through finer grades until you run out of finer grits. Then switch to a buffer and use polishing compounds. You might also experiment with a fine Scotch-Bright wheel if you have access to one. I use the wheel in our machine shop to put bright polish on all my metal parts. It is very fast and blows though dirt & rust.

Pay a bit of attention to the bore where your shackle pin goes. The bore should be pretty smooth so there are no crevices to propagate a stress corrosion crack. An adjustable reamer is really excellent for this - or polish away at it.

I used the DA sander to expose the cracks in the old SS plates as well.

[DawnTreader]

I recently polished chainplates I made from 316 ss that had a mill scale finish. I used a variable speed angle grinder for sanding. Progressed up in grit from a 60 grit hard disk to a 600 grit stikit disk on a soft backing pad. As I went up in grit I slowed the grinder down. This left the metal with an acceptable finish, but I wanted something closer to mirror like, so I then polished with a ss rouge, using first a sisal wheel then a medium soft wheel chucked into a drill. 6 chainplates can be done in an easy day.

[kk4lux]

Jasco Paint stripper works surprisingly well taking rust spots off stainless winches and stanchions and so on. Use it all the time. Just wipe it on leave a few minutes and then scrub it off with an abrasive pad like a Greenie.