A while back I posted some pictures of a second-hand Selmer Bb trombone which I'd bought. I've been told (on a bone forum), Selmer use a rather soft lacquer on their brass, which scratches very easily - and then the brass underneath corrodes. The problem is, as I found on mine, the corrosion doesn't limit itself to the scratch, but spreads sideways under the lacquer - which then means that 1. you can't polish it off; and 2. it carries on eating into the brass. This is what my bone looked like at the time of purchase, when I was trying paint stripper to remove the lacquer (it didn't even soften it!): The pale green stripes and flecks are the green verdigris showing through the lacquer; the white gloppy stuff is the paint 'remover'. Second picture shows what I found when I managed to shift some of the lacquer with extremely hot water and a pot scourer (a painfully slow and laborious job): The areas enclosed in a pale outline show where the corrosion had been eating downwards into the brass, and the pale line is the shelf at the edge of the corroded area. Granted, at that time it was probably only a few thousandths of an inch deep, but the brass is not that thick to start with - and if I hadn't stripped the lacquer off, it would have carried on eating away at the brass until it punctured it. The third picture shows what it looks like, tonight. I still have a lot of lacquer to clear from the fiddly bits, but by far the worst of the corrosion was on the bell, so I went for that first. Brasso is not the finest of polishes, and I will switch to a more delicate one once I've got down to bright metal; but even if I never achieve the mirror finish that the pro brass repairers can achieve on their buffing mops, at least I'll have killed off the corrosion and will be able to keep it at bay. I've also bought a little pot of 'Renaissance' Micro-Crystalline Wax Polish to try, once I've got it up to a decent shine. Unlike things like beeswax, this stuff finishes up absolutely dry, so when you touch the surface, it doesn't smear, doesn't leave fingerprints, and doesn't leave your fingers waxy. It's used by some of the fussiest curators in the world - the staff of the Victoria & Albert Museum. I'll let you know how I get on with it. Jack E MTA - all of the above begs the question; if brass instrument makers routinely offer EVERY other instrument used in brass bands in silver plate - why are trombones the exception? Many good makers sell top quality bones in lacquer only, so if you want the far more durable silver finish, your only option is to get a pro instrument finisher to strip the lacquer, repolish it, and then plate it - at a cost running into hundreds! I've asked lots of people about this, and NONE of them have ever come up with an answer that makes any sense at all.