I tried to post this just as the website crumbled (I take full responsibility ), so in the meantime I asked elsewhere. Apologies if you've seen it before.
Back in this thread, the existence of soldering grain was revealed unto me. I'd never heard of it before, but it might just be the thing for one particular job.
I'm not keen on Walsh's price, so I thought I could put a kit together myself with a stainless steel Balti dish from Tesco and some grit from somewhere like UKGE or Capital City. What size grit though? Anyone?