Alluminium/Alloy Corrosion woes

[Wyberton John]

I'm doing a deep clean on my Fazer thou, but having some issues buffing up the silverware as much as I would like.

The hangers, rearsets (whatever the normal ones are called) and side plates are badly corroded. After a soapy water scrub, I left them soaking overnight in a mix of water and white vinegar, which did a nice job on them - but the corrosion was still very apparent.

I then used brasso wadding on them, which makes them shine nicely - but that corrosion is ever-present. Even after a good rubbing with Mother's Mag, they were super-shiney, but after a while the corrosion shows through yet again.

Is it actually possible to get rid of this blight on my shineyware, or am I stuck with just trying to camouflage it under the polish?

I did take these shots in a way that shows it worse than it looks, just to illustrate the problem:

https://i.postimg.cc/BPg2QhPb/DSCF2340.jpg

https://i.postimg.cc/grq7ZmvX/DSCF2339.jpg

https://i.postimg.cc/JtWg0GBC/DSCF2335.jpg
____________________
Fazer Thou Gen 1

[Teflon-Mike]

Most 'Aluminium', isn't, calling it 'alloy' is technically more correct......
What the constituents of the 'alloy' may be? Well.... on sheet or tube, there's a bunch of 'standard' alloys they may be. There's even more casting alloys though, and on a cast part, its any-one's guess really.

Point of this, though, is that 'most' non-structural cast alloy parts are usually made with a pretty cheap, or at least cheap to cast alloy containing quite a bit of zinc...... you know like the stuff they 'galvanise' buckets with, that, when new are wonderful and shiny with a sort of camouflage pattern in silver... that's the individual crystals of the zinc coating, illuminated a little by a final acid rinse.....

Vinegar...... its acid....... yup, it will do a pretty good job of helping clean up manky alloy... BUT.... aluminium doesn't need to be galvanised... it self galvanises, and is often helped by a little anodise.

Basically.... aluminium 'rusts' just like steel; or iron, but instead of oxidising to form a horrible red layer that grows, once the surface has oxidised, that layer of aluminium oxide makes a protective barrier to stop any more oxidisation.....

Scratch it... the surface oxide layer is broken, the fresh metal beneath cab oxidise, but soon as it does, its 'repaired' the barrier.

Moral being, DONT polish alloy... you are just rubbing away the natural surface protection, to make it shiny! It'll soon dull down, and you'll have to do it again!

Anodise! Had to do this at school, ISTR with a lab bench supply and a bottle of food colouring! Essentially you stick the part on a pot of water and hang it off a wire, to make one terminal of an eclectic circuit, whilst you electrolyse the water. Another school experiment, I suspect they aren't allowed to let kids do these days cos of H&S, but.. I always get them the wrong way round.... anode and cathode, one positive one negative, and err... well, if you stick a test tube over them, as the electric goes through the water it breaks down the H2O into Hydrogen and oxygen.

More aside.... the test tube that collects the hydrogen goes 'pop' when you stick a glowing spill in it.... 'cos Hydrogen explodes! the test tube that collects the oxygen will, briefly, re-light a glowing spill when you put it in the gas, cos flames like oxygen.... blooming eck, all that tax payers money and chemistry teachers pay wasn't 'quite' wasted then!

Howebler, when anodising, basically you use the aluminium as the electrode that collects the oxygen, and the electrolytic reaction you are promoting, a) ensured pretty much the whole surface area gets coasted, but b) unlike in free air which is only.... err... bludy ell! I was RIGHT! See them teachers must have learned me summat! (In probably thier defense, as well as mine, though it WAS rather a long time ago!) BUT only aprox 15% of air is oxygen. 80% of it is nitrogen, the rest 'other gasses' depending how close the cows are! ANYWAY, in essentially 'pure' oxygen during electrolysis, forcing the oxidisation, you get much denser oxide, that's far less flour-like, and a lot denser, on the surface. More, if you stick a dye, like food colouring in the water... it dyes the oxide layer. Hence the lurid golds and yellows adorning so many Blandits.

IF you are at all inclined... and you MAY need a bored ten year old on a wet winter'#s week-end with a broken Nintendo to occupy to be so inclined.... it can be a wonderful way to waste the day, with a battery charger, and old ice-cream tub, and whatever cake colourings you can find in the cupboard, and maybe a water-colour paint set, seeiung just how many colours of anodise you can get on bits of old Land-Rover... or green-house, or any other convenient bit of scrap alloy TBH... cos they cant do this sort of thing in the schools no more, aparently!

Anyhow... this brings me onto 'Passivation', which is a 'sort' of chemical electrolysis, that sort of does a similar thing. More used actually on steel, like the brackets that come with bits of tower computer or to hang a TV on, but it 'surface hardens' the metal, and creates an electrofertic barier layer at the surface.... and some of the pasivation treatments work on alloy too.

BUT... they aren't often all that 'cheap' and they usually leave the metal a different colour.... and folk expect metal to be a shiny grey-silver colour.....

SO, most 'natural' alloy we get, is actually NOT bare alloy. Its polished and then laquered.

SO, if it goes manky.... its either dirty, and JUST needs washing.... or the coating has been worn away, and the metal beneath is oxidising.... see above.... polish that up, it just gonna keep doing it, you is polishing away its natural surface protection..... and if you is chucking it in acid..... helping it re-oxidise!

Take from this what you will......

BUT, if you want a shiny polished aluminium to stay looking shiney and polished... then you have to put a clear coat over that to give it the barrier to oxidisation, the oxide layer would.

If you want it to stay looking 'clean' and not go furry.... then, you probably need to anodise or passivate, to get a uniform protective oxide layer... with warning that this will self heal if the surface oxide is scratched.... BUT scratching it severely like when you take a chuffing brillo pad to it..... will just encourage the dang thing to oxidise more! Especially if the brillo pad be soaked in an acidic solution like vinegar!

PERSONALLY..... I tend to just NOT polish alloy! I've had the old Cota, now, remarkeably, just over 30 years.... when it was built they were so proud that so much was actual 'aluminium alloy' it was all stamped, at the factory "Montesa Akront" and the engine cases proudly boasted the cast legend "Magnesio" cos the outer cases at least, are magnesium alloy.. of course Yamaha just used plastic.... which was as tough as light and a dang site cheaper, but still....

Many bits have tarnished over the years; particularly the hubs, that are rather awkward to get at and polish... so they go sort of charcoal grey... and I live with it.... its the 'patina' of age and use.

The Seven-Fifty? With its air-cooled alloy engine, had by about seven or eight years ago, gone rather furry, having lost pretty much all of its pasivated coating over the decades....... so I painted it black! bits probably need touching up by now.... but what the heck! Dang site less work to re-spray a cam-cover than spend weeks rubbing with solvol to make it look worse in a weeks time!

A-N-D on parts that aren't so heated? OR even with the right laquer if they are? Well, same solution, different colour! Polish, then paint... like the factory probably did to start with.

THEN, in use DO NOT polish and certainly over polish alloy! Wash with copiouse quantities of water and nothing more caustic than regular soap or washing up liquid!
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[Riejufixing]

[Wyberton John]

Thank you for your suggestions
____________________
Fazer Thou Gen 1

[EazyDuz]

Easiest and fastest way? A battery/electric drill, a tube of Autosol/Autoglym metal polish and this kit:

https://www.ebay.co.uk/itm/Car-Polisher-Pad-Buffer-Gross-Polish-Polishing-Kit-Set-Drill-Adapter-UK-STOCK/202494785221?epid=2014366998&hash=item2f25a136c5:g:3TEAAOSwww9b4q1L:rk:3:pf:1&frcectupt=true

When you're done clean polish residue off and I guess you could try a decent wax/sealant and see how it holds up. Like a good car paint sealant. If it protects paint I dont see why it couldnt protect metal.
____________________
To shreds you say? Tss tss tss

[Riejufixing]

Further to that:

https://www.metalpolishingsupplies.co.uk/polishing-kits-angle-grinder/

Also on eBay.

Be careful with angle grinders.

[Wyberton John]

Thanks again - and for the useful links (on it's way)
____________________
Fazer Thou Gen 1

[Robby]

They are likely to be lacquered, but the corrosion is under the lacquer. So to get them properly shiny, you need to buff back the lacquer and corrosion.

This leaves you with no lacquer, so corrosion can set in quickly. Varies a lot from bike to bike. A lot of Suzukis fur up in no time.

Treating bare alloy with ACF50 does a good job of holding the corrosion at bay, particularly on rougher things like cast engine cases.

[misscrabstick]

Strip off laquer with a soft wire wheel in a drill, polish until happy with the finish, degrease the surfaces then paint with two pack clear coat.

[Pete.]

As a novice if you hit those parts with a buffer or wire wheel you'll end up with a patchy finish that still needs laquering and you'll round off the nice crisp edges.

Strip off all the parts and take them for bead/wet blasting then either laquer or paint them. They will look like brand new off the shelf parts.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Riejufixing]

[stinkwheel]

Can't see them while you're riding it.

Stop polishing, get riding.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Wyberton John]

Hey that's a good idea!

The buyer can see it, though, as I'm trying to p/x it on a later one
____________________
Fazer Thou Gen 1