Ride tomorrow Sunday 1 November

**motorbyclist** · 2nd November 2009, 15:30

come to think of it, my rvf carbies (externally) are a good example of it too - and the slide within Brown Fury's carby.

I'm not saying it's structural, but it IS aesthetic - and the better the polished surface the better it looks and the longer it will last.

**jono035** · 2nd November 2009, 15:43

Yeah, and bear in mind that we're not too far from a marine environment. Anodizing can help but that's not a DIY job.

Cast ally sucks terribly at resisting surface corrosion, just look at all the fucked-out security camera housings around the place. It takes a hell of a lot longer to become a structural issue but it still corrodes if not looked after.

If you're willing to give it a clean and rub down every couple of months and don't let it get anywhere near lime/sea etc. and keep it mostly dry then it'll do fine without a top coat.

Vifferman - what would you suggest instead of clearcoat? Discolouration is a badly selected clearcoat and flaking is a combination of that or poor surface prep.

**ital916** · 2nd November 2009, 16:54

Originally Posted by motorbyclist

excuse my terminology and look at ross's vfr chassis for what i mean - the oxide layer has it's limits, and aluminium can corrode (or "rot")

I wasnt arguing the fact that it corrodes, it does indeed corrode (not rust real_wolf) but, it takes a fair bit of abusive conditions/elements to strip the protective oxide layer from aluminium and cause structural damage. Cosmetic corrosion occurs over time, unless you really keep on top of it.

**Danae** · 3rd November 2009, 10:57

Originally Posted by motorbyclist

...but i'd imagine it'd be fine for atleast 18 months if you polish it well enough - the smoother the finish the longer it'll last and the easier it will be to clean (and the cooler it will look)

Originally Posted by ital916

Tis very difficult for aluminium to corrode thanks to its very protective oxide layer, so freshly stripped and polished alu rims should be sweet from corrosion....you scream, I scream, we all scream for ALUMINIUM!

Originally Posted by ital916

Cosmetic corrosion occurs over time, unless you really keep on top of it.

Like 18 months kind of time?

**jono035** · 3rd November 2009, 11:10

Originally Posted by Danae

Like 18 months kind of time?

Depends on the aluminium and environment but 18 months for cast ally to look pretty crappy is probably about right.

At the port anything unprotected and cast turned to crap in a month, but that's a pretty nasty environment. The cast ally painted enclosures that were protected from standing water had corroded right out from under the paint and were starting to get pretty dodgy after 18 months.

I'd guess in this case it may take easily more than 18 months to end up looking like motorbyclist's pic there but may only take a month before they need repolishing if you want them to shine?

Edit: It isn't going to damage your wheels in any way at all to leave them uncoated so the logical step is to just do it and report the results so that we all know for sure what the deal is... Worst comes to the worst in a couple of months time you give them a quick sand up and then coat them. The marine-grade anodizing for protection looks pretty nice too, very slight gunmetal tinge to the ally and it's pretty rugged. We've had enclosures made from aluminium extrusion and then marine-grade anodized that are right at the waters edge and still look perfect after a few years...

**Real_Wolf** · 3rd November 2009, 14:19

Originally Posted by R6_kid

Aluminium doesn't rust, it oxidises!

What is rust on Iron.

Lets see, I believe it is a form of Fe2O3 usually, which... wow... it seems to be an oxide. Yes there are other rust products, but iron oxide is a common one from exposure to air and moisture, along with some Fe(Oh) product

Originally Posted by ital916

it does indeed corrode (not rust real_wolf)

Sorry, wrong terminology, I was using rust as the Metal turning into an Ion, through contact with other non-aluminium things, such as other metals or water or air, unlike rust which does not include other metals or other metal ions in a salt

**motorbyclist** · 4th November 2009, 16:55

go-go-gadget high school chemistry!

Rust is what we call the orange stuff a chemist might refer to as an iron oxide. Rusting is the process of iron reacting with oxygen.

Oxidisation is a chemical reaction process in which the substance being oxidised donates** electrons to the substance "oxidising" it.

Oxidisation has nothing to do with whether or not oxygen is involved; oxygen is just one of the more common (and powerful) chemicals to cause it.

The chemical corrosion of aluminium I'm referring to is not normally a reaction with oxygen, which forms a protective aluminium oxide layer, but a reaction with a halide such as chloride ions which we find in abundance in tap, ground and sea water. This forms the white aluminium chloride (aluminium salt) crystals what will ruin the aesthetics of an aluminium surface.

**electron flow may be the other way round, I havn't touched redox since high-school

**Phurrball** · 4th November 2009, 19:27

Didn't take long for the Damp Lainghom environment to take its toll on my formerly Arizona and Nelson housed VFR. In about 8 months things were starting to fur up. Not happy, but I live in a shitty hovel and the bikes fare worse in their shed

Not sure about teh chassis though Andrew - definitely the engine, and even through the powdercoat on the wheels (FFS Honda!)

Sigh.

EDIT - WTF is that in your pic Andrew? Looks more like a car engine than a bike - toothed-belt driven waterpump and cams perchance?