[Boli]

You are thinking that the corrosion will occur because of the AIR.... this is not true. Admittedly an untreated (raw) piece of ALU will corrode in the air but the resulting Aluminium oxide that will coat the metal actually protects further corrosion... this is why ALU can appear dull.... you are not really seeing the ALU but the thin (VERY thin coat of Aluminium Oxide).

What the anodising does is protect the metal from the galvanic "battery effect" cause by dissimilar metals connected by a ion rich solution (Your water coolant)... the ALU - if bare will gradually disintegrate unless precautions are taken... thus the practice of adding additives to the water (or use of deionised water) also anodising any ALU block fittings.

The reason the WHOLE of the ALU block is anodised is most likely ease of production more than anything else where as realistically only the part of the ALU block in contact with the coolant need be anodised. (naturally with a "buffer-zone" ). Removing the anodised coating from one side of the block will not have an adverse effect on the block at all. So the thing is entirely safe... the clear lacquer is only to prevent the aforementioned ALU "rust" effect taking place and keeping the metal nice and shiny.

Of course if the anodising coating is scratched on the INSIDE (were it has contact with the coolant) your "paint effect" is true... there WILL be corrosion which will spread so you have to be careful NOT to scratch the inside.


~ Boli

*Boli thinks about investing in a spell checker... or at least a secretary with nice legs *