I'm not sure if it's appropriate to ask here, but I would assume many people in electronics would have experience with this.
I'm enclosing an RF sensitive PCB into an sealed aluminium enclosure. Aluminum is chosen because it is lightweight for shipping, and also a good thermal conductor which is required as the enclosure acts as the heatsink.
The big concern however, is that the circuit needs to be grounded to the aluminium enclosure for proper shielding. If the enclosure is not conductive and low impedance GNDed to the PCB then there are problems with internal noise generation from switching circuits being transferred to RF sensitive parts of the circuit.
The PCB slides into a railing and the edges of the PCB have exposed GND rails. Aluminum is not conductive on the surface due to its oxidization effects, and I have no way of applying some sort of pressure or screw to the enclsoure to force conductivity through the oxide layer.
What can be changed however it the coating on the aluminium. From doing research it looks like the coating I require is nickel plating, or tin plating. I've also looked into RoHs safe class 3 chromate conversion, but even this writes that some contact pressure is needed for conduction. Tin plated steel may be an alternative, but is a poor thermal conductor and is much heavier.
Does anyone have experience with conductive aluminum for RF shielded enclosures? What is commonly used? Does tin or nickel plating aluminum cost a lot more?
EDIT: Added an example image of the enclosure and PCB.