[steve]

I seem to remember some metals react to each other, can't remember what it was, is it stainless steel and aluminium or something? causes corrosion? or am i imagning things?

[royce]

yes to stainless and aluminium
there are others but I cant remember them

[steve]

what happens? do both metals corrode, or just one, which one?

[royce]

good question

what are you doing? you can get a paste that you put between the 2 to prevent corrosion, they use it on boats

[Damo]

Dissimilar metals is the term you are looking for. Download the PDF from this page, it should give all the info you need.

[steve]

I put some stainless steel bolts in my aluminim tray, and then remembered that there may be a reason why i shouldn't. Not sure if it matters too much.

i'll have a look at that page sometime Damo.

[steve]

going by that PDF from bluescope, i think the aluminium will corrode and not the stainless, but can only occur when it is wet, but my eyes glazed over after a few lines of text

[royce]

pull it apart and paint it and put it back together

[Taff]

needs to be wet. any steel and aluminium will slowly corrode.

in saying that though, the rest of the car will be well rusted away before anything goes wrong in your tray. Look at landrovers, steel frame covered in alloy panels.... the body far outlasts the rusting chassis hidden below