I think there is a book in the workshop practice series, Ah yes No 11, for the sake of £8 it might save a lot of wasted effort or money. Noel.

To answer your initial questions…

Yes, the work must hang in the tank and with a good electrical connection. If there are through-holes in it you can hang it on wire from a copper-tube bus-bar- as in a small plating-works where I once worked.

The solution may need warming (the manufacturers' instructions should advise).

Perhaps more importantly, it will need agitating for more even plating. One way is to blow air through it, rather like an aquarium aerator (one might work in a small tank). I forget if our plant used that of a circulating-pump, the delivery being through perforated pipes along the tank floor, but the important point is keeping the solution stirred. A mechanical stirrer based on a propellor-type paint-stirrer could be effective.

The work does need be absolutely clean, including down screw-holes and the like, usually achieved by a detergent though with care as alkalis will etch aluminium. It is also better to have no sharp edges, though it didn't seem to matter on the hundreds of thousands of brass mascara-brush ferules we nickel – gold plated! The smaller ones were threaded onto copper wire like necklaces; the larger clipped to special jigs.

To protect a threaded hole, I would suggest inserting a plastic – not metal – screw long enough for the tapping but leaving plenty of room below its head.