Alloy cleaning

hey guys, i saw a while back someone post a link explaining how to get an old alloy stem all nice and shiny. cant find it anymore.

anyone know any good links/or got any of their own advice? i remember it included:
Oven cleaner
Wet and dry sand paper
and some polish

cant remember the rest


heres a link
I mention draino to remove anodising.
You will need to remove anodising in order to polish.
Try polishing first with silvo if your rag doesnt start going black your parts are probably anodised theres not much point sanding ano by hand either it’s pretty hard

THis one?

I believe the ‘anodize remover’ is caustic soda, but I’m prepared to stand corrected. My granny used to pour it down drains because she thought Draino was a bit posh.

I also use mag wheel cleaner to get caked-on grime and tarnish off old alu parts…works a treat.

If you want a satin rather than shiny finish or to buff out fine scratches before a final polish “essteele stainless steel and copper cookware cleaner” is the DG.

While we’re broadly on the topic, automotive gasket remover will take off powdercoat.

na some guy was giving a tutorial. I remember now… he had a list of equipment including all i said about plus a bottle of beer for the part while he waited. Was an old stem, came out looking really shiny. I thought i had saved the link but no dice. Someone on here must know, since they did post it :stuck_out_tongue: annnnyyone?

i went out and bought the oven cleaner today, as well as an new old seat post.

gotto get cleaning

i think this might be the post you were looking for

not too sure about the combo of beer and oven cleaner though

It actually has more ‘active ingredient’ than Draino, and it’s cheaper!

The “active ingredient” is sodium hydroxide (NaOH). I mention draino as i have used it successfully in the past, also (and more importantly, though other methods may do the same) it results in green bubbles for propper mad scientist moments. If you try draino make sure to check the tin there is a wussy version out there which has little or no NaOH in it

saibura thats the one.

thank you.

however i think we should make our own method…

so at the moment we’re think

Draino? or caustic soda?




what you think?

im gonna try the other guys method… stem looked pretty neat

ill post results. gonna try seat post as well, an some shitty drops.

this is the final result of my shining.

more sanding and more polishing would have enhanced the shine id say

pretty good method

Can you ruin the aluminium if left with caustic soda on it for too long?
I’m thinking about doing this to a set of hubs.
If I left the hub shells covered in caustic soda overnight is there a chance of wrecking threads or melting the shell?
…maybe I should read the guys tutorial also…

You’ll end up with pitting corrosion on the aluminium, ruining the surface finish. The NaOH destroys the passivation that you usually get with aluminium exposed to water (tight AL2O3 layer, same concept as the Cr oxide on stainless steel) by dissolving the oxide layer. Then the Al is dissolved by the NaOH + H2O, leaving sodium ions and an aluminate in solution.

For extreme ‘stuck alloy stem in steel fork removal’ you can leave it in NaOH + H2O and dissolve it entirely, leaving the fork behind.

Not sure on the time to pitting, if you can’t find out, use a sacrificial component first. Or just leave it for long enough to strip the anodising.

That’s the thing I don’t understand- once you have polished a component, how do you maintain the polish? I would have thought the aluminium would quickly oxidose again leaving a dull finish. Am I missing something?

Just keep polishing, just keep polishing, just keep polishing, polishing, polishing :smiley:

About once a week should do.

It does, but if you have a better base (~1-5um surface roughness) following your sand/polish it will still look better than when you started, and will be easier to touch up.

Or you can clear coat over it.

Or plate a noble metal (eg Rh/Pt/Au) onto it. :roll:


Clear coat +1.
Did this to stem and cranks last year, still looking great.