I’m not going to profess to knowing much on this topic, but from what I recall stainless steel is considerably more noble on the galvanic series than aluminium and steel. For this reason I used sealed aluminium rivets, else (as I understand things), by using stainless fasteners the aluminium will corrode in the region of the stainless fastener, when in a damp environment. If you use aluminium fasteners, then the only metals in the damp environment are aluminium, and thus the potential difference of the two materials should be very small (slight amount due to different grades of aluminium).
Like I said, I’m far from an expert, and my knowledge is based upon shady memories of a-level chemistry from well over a decade ago, but if you’re considering the longevity of what you’re building, it’s probably worth giving some thought to moisture exposure and galvanic corrosion.
I think sealed rivets are wise, as they won’t allow moisture to enter the chassis tubes through the centre of the rivet.
|