WGB 

I have a Sugino SP-KC alloy seatpost that is rusted and dull. Not the flake off kind of rust but the kind of etched into the metal rusting. I don't want to use steel wool or sand paper as I want to leave as much detail on the post as possible.

I went to the hardware store where choices were very limited, either a Mothers chrome and aluminum polish or a brand named "AutoSol". I explained I wanted to remove any rusting and polish the post and the nice man at the store told me that people with bikes preferred the Autosol product over the Mothers.

I purchased the Autosol and went home and applied it and waited several minutes and then buffed the post with a clean dry rag. I did this twice to the bottom of the post.

It did remove some of the rust and what wasn't rusty shines, but I am not happy and believe it could be better. I think I will return the product and seek something else.

I could try using a Dremel tool with a polishing bit or steel wool but first I'm asking of anyone knows of a better product to use or alternatively would 0000 steel wool, perhaps used with the the Autosol or another product as a lubricant.

Does anyone have a better product they'd use or a better idea?

Iowa10Speed

Do a Google search on 'khatfull polishing'. You'll find some classic Bike Forum threads on polishing. I use some techniques I learned there and get great results.

For my purposes, I do a basic wet sanding with successively finer grits of sandpaper (400, 1000, 2000) depending on the severity of scratches and discolorations that need to be removed, then finish with Mothers Mag and Aluminum Polish.

The forum threads have much more detail and options that will be helpful.

Iowa10Speed

This is the thread I was remembering ...

https://www.bikeforums.net/classic-vintage/697520-khatfulls-aluminum-polishing-thread.html

kc0yef 

Did you ever sand too far and make the seatpost too small?

QUOTE=Iowa10Speed;20228165]Do a Google search on 'khatfull polishing'. You'll find some classic Bike Forum threads on polishing. I use some techniques I learned there and get great results.

For my purposes, I do a basic wet sanding with successively finer grits of sandpaper (400, 1000, 2000) depending on the severity of scratches and discolorations that need to be removed, then finish with Mothers Mag and Aluminum Polish.

The forum threads have much more detail and options that will be helpful.[/QUOTE]

m_sasso

Started off in about the same condition as yours, all done by hand, sandpaper and Mothers

jj1091

Those V-shaped twisting scratches won't come out with either polishing compound or steel wool. They'll need to be sanded out. The best bet, since you're concerned about not removing too mush material, is to start with a finer grade sandpaper, then move to a heavier grade if that doesn't work. Whatever you do, it will take successive levels of sanding and then polishing to have decent results.

JaccoW

That's an excellent shine! What do you use for the infill? Just regular acrylic paint?

Salamandrine 

Since the main problem is the rust stains, try some barkeeper's friend. Good for removing rust stains. It will turn the aluminum gray, but that can be polished out again with your metal polish. It's mainly oxalic acid, so don't leave it on too long or it will eat the aluminum and the rust. It will chemically react. Try a small area first.

I'd suggest avoiding any abrasive more coarse than a scouring kitchen sponge or some extra fine scotchbrite.

Autosol and similar polishes are not meant to be used that way, btw. It's a very fine polishing compound, not a chemical cleaner. Dip a rag in a bit of it and rub hard, then buff with a clean dry rag.

Vince Hoffmann

I've polished aluminum many times with sand paper with glorious results. Don't worry about sanding the detail off, it won't happen unless you use 80 grit and a power tool. Polishing rusty steel will take longer than aluminum.
Start with 400 wet/dry (use it wet) to get the rust areas down to good metal, then switch to 800. It's going to take some elbow grease. Then finish up on the bench buffer with polishing compound.

WGB 

Thank you all - esp M Sasso (that post isn't just impressive, it's a challenge)

Will shine it up this weekend.

I think that ending with a post like yours will feel better than buying an NOS post because every time I take the bike out it will register - I did that, which to me is a huge part of C&V.

Salamandrine - could I use Eaporust or similar first (never seen "Barkeepers friend before) and then move to the polishing compound?

Ps has anyone had any good (safe - nondestructive) results with a Dremel and buffing pads??.

WGB 

Ps has anyone had any good (safe - nondestructive) results with a Dremel and buffing pads??.

Just read the kahtfull post and screw the Dremel - at least until I know what I am talking about!!!

WGB 

ok - just read the khatfull post and so screw the dremel at least until i know what I am doing

Salamandrine 

Yeah, you can use evaporust. It's better actually. Only suggested barkeepers friend 'cause it's easy to find. Most grocery stores sell it right next to the comet cleanser.

The newer dremel buff pads with a little mini cloth buffing wheel work pretty well for small parts. The old felt ones are useless. IMHO... For something like this, it's easier IME to polish by hand. (or with a full size buffing wheel)

Iowa10Speed

Seat posts and stems are ideal first projects because you can practice on the section that's hidden inside the bike.

I had that "what am I getting myself into?" feeling on my first project but that quickly faded. You'll doubt yourself, especially if you have to resort to more aggressive grits like 400. The finish goes a horrid dull gray and the part looks ruined. But with each finer grit the finish clearly gets better. The final polish with Mother's is magic.

On fluted seatposts, the indented parts were often not highly polished originally. They are a little bumpy. Try using just Mothers and no sandpaper. That may clean and shine the metal to your liking.

gaucho777 

I would not return the original polish on principle. It seems to have done its job adequately. That post wasn’t going to shine like m_sasso’s unless it got some sanding before polishing.

The only details appear to be inside the flutes and those don’t need sanding. But you are right not to want to sand over details. My Campy posts just get minimal sanding on engraved logos before polishing.

Salamandrine 

Polish won't work unless you rub rub rub. It's not some sort of dip. Keep it.

WGB 

No, you are right about the polish, I bought it and used it and won't return it. Based on what I got here, I get it works if used right.

I took what was stated here and tried wet 200 sandpaper. I then rebuffed with the polish. This is only 5 minutes with wet sandpaper! Impressed so far as I didn't even see the writing in the small circle because it was so stained. The differences in the shine in the photos is simply the first is in a bit of shade and the second is in bright sun. It's still a little too cold here to work outside with wet hands for long but spring is coming.

My question is about the abrasive balls mentioned by KHatfull. Do these get into the small spots (like where the numbers are on the side of the post pictured)?

markk900

Nice work so far! You can work up from the 200 to 400/600/1000 before polishing. Be wary of over-polishing (unless you want it to shine like chrome) - often even new items like this were not super bright.

Also, Autosol is well respected in the motorcycle community, but I also like the cotton impregnated polishes like Nev-R-Dull for the final polish.

WGB 

Markk900

The polish was just there to confirm I was on the right track. Next will be 600, 1000, 1200 and possibly 1500 paper, then a quick polish.

Will have to try either a pad or one of those abrasive balls on a drill.

markk900

Nice! To be perfectly honest, when doing motorcycle parts at least I found there to be diminishing returns above about 600 grit.... 600 or 800, with a decent finishing polish was always quite acceptable.

I did the cases and other alloy bits in front of the TV one winter many moons ago....No buffing wheel as I didn't have a place for one.

WGB 

Last question (hopefully) - will these techniques work on these Diacompe brakes as well??

Vince Hoffmann

Agreed. I've found 400 wet sanding is as far as I ever needed to go before hitting the buffer.

bark_eater 

Can anyone recommend an inexpensive and portable low speed buffer suitable for small parts? I have to do all my "dirty" work outside right now.

SquidPuppet

You don't need power tools when dealing with aluminum. Go all the way to 2000 sandpaper. Then polish (I like Blue Magic) by hand. It goes easy and fast.

On the post below I went 600, 800, 1000, 1500, 2000 and then two applications of polish. It was WAY uglier than yours when I started. It took all of 30 minutes. Granted, it has no detail, but it gives you an idea of how fast it goes.

SquidPuppet

Yes.