If you haven't seen these two incredible bronzes, it's really worth having a look at the Riace website - www.bronzidiriace.org. Their conservation and theories about their manufacture are really interesting and quite controversial.
Found by a snorkelling chemist in only eight metres of water in the Ionian sea in 1972, their conservation has been a lengthy and continuing battle against salts and concretions. They were mechanically cleaned for two years in Calabria before being transported to the restoration centre of the Soprintendenza Archeologica of Tuscany for desalination. Unfortunately, the first attempts were carried out with the salt-laden casting cores still inside the statues, so they weren't massively successful.
Work continued through the 1980s and 90s to try to stabilise the bronzes and excavate fully the casting cores, which could only be done through very small holes in the feet of the warriors. A huge amount of information has been revealed and published (in Italian, mostly) in three lavishly illustrated volumes (from 2003, I bronzi di Riace: restauro come conoscenza. Roma:Artemide) and several articles.
The current conservation programme seems to be aiming to undertake chemical cleaning with benzotriazole, to investigate the solders used and to map the ancient repairs. It would have been so interesting to see how this could be accomplished in front of the public, and how the interventions were explained. Unfortunately, there was no time or money for a field trip to Calabria! But if you find yourself in that part of the world, do try to visit the Regional Council exhibition -http://www.bronzidiriace.org/bdreng/the-bronzes.html