[paul_c5x4]

I've seen dichromates on ebay a couple of times, but I'd advise caution if you're think of going that route. There are a few companies that sell to the education sector that will also supply the general public, but in general, dichromates are getting difficult to get hold of. This is thanks to E.U. regulations covering hazardous chemicals rather than any conspiracy against imaginary terrorist groups.

T.R. Bonnymans supplies a range of useful chemicals to the "general" public, and for more specialist items, you could try Abbey Chemicals.

edit: apcpure.com list Ammonium Dichromate. 100g for £17.20 plus P&P