I have the type of weed whacker that takes about a foot long plastic "string".
I buy the weed whacker string in bulk, so it's cheap but it only lasts a few minutes in touch terrain.
I wonder. Would it work to just put an electrical wire, maybe 14 gauge or so, into the weed whacker?
I mean, why does it use plastic? Why not copper or steel wire (from a coat hanger perhaps)?
Is it that it would be too dangerous? (But plenty of things are dangerous.)