Hi Doug
It actually plates the inside of the chamber - but each coating will only be microns thick I think? The aluminium coils are only a few inches long, wire in fact. It just makes for a very shiny chamber and I don't think any attempt would be made to recover the material? After all, aluminium isn't that expensive. Now if they were doing 22 carat gold on the other hand....
It's a very interesting process. I made some enquiries about getting our fittings plated a while ago and spent an afternoon at one factory on the far side of Derbyshire near the M1. You can't see the process operating for obvious reasons, but when they release the vacuum and open the chamber (rather like an oil drum but about 5 foot in diameter) the results are spectacular.
Oddly enough, in itself, it isn't a hugely expensive process, the additional costs come with the special finishing, setting the fittings up on the 'trees' that I mentioned in my first post, and getting all of the stuff to and from the factory - it all has to be handled very carefully.
Regards, Malc
