Transformer tape

I'm sure a lot of you out there peel the tape off your transformers and CBM's. I usually don't have an issue... however, I just got a stash of about 50 monitors and each monitor I take apart the transformers have the yellow tape thats pretty old. I peel it off but some residual yellow stays stuck and it's impossible to get off. I was wondering if there was a little residual tape on some of my copper wire do you think the yards will take it like that? Is there some sort of liquid I could maybe soak it in to get it off easier? Just looking for some advice if someone has run into that stubborn layered transformer tape thats old.

That wire will go as #2 copper due to the size so a little contamination should be fine.

Can't say for sure about your yard but they should not dock you just for the residue. Like was said, it'll go for #2 anyway.
Whatever the cost of the "liquid" you would use to clean the copper, you won't gain that much extra money from the copper to pay for the mystery liquid.

Why would you spend all that time taking tape off of transformers, just throw them in a bucket or a box and take them to the yard. I sell the copper from motors with the string still on it so why would some tape make a diffrance.