plumbing fittings, heavy guage ground wire, old weather vanes, copper nails, old standing seam copper roof panels, old copper rain gutters, etc. Check some salvage yards in your area. I assume you want small granular peices for ease of compaction? There is the problem, how do you grind the stuff up?
I must say I'm quite alarmed how non-chalantly this discussion has turned to materials for bypassing fuses . . . I'm thinking perhaps this may be a Bad Move from a safety standpoint.Fuse in the power cord? What is the problem?
Then I reread the OP's post.....
where can i find copper slug to put in my power cond?
Not a power cord..... A power conditioner....