Empty Plastic spools

[Mitchell]

Looking for a source for empty plastic spools for reels.

Thanks

[miketsp]

I use bricklayer's plumb lines. Just cost a couple of USD, I throw away the cheap & nasty nylon line, drill holes around one side for the double-ender clip and rewind them with 20 - 40m of 3mm polyester line.
Total cost excluding clip, less than 5USD.