I have a sink strainer that just spins with the sink tool I have. It slides back and forth and won't move up. I have a heat gun. What do I need to heat up to get this thing out?

Sorry this is a hard question to answer

Dagazz, you need to hold the nut from underneath the sink. Here's a link. Good luck

Creative Homeowner - Dream ~ Design ~ Create.

Assuming you are trying to remove the sink strainer;
Assuming that the sink strainer has cross bars;
Assuming that your arms are not long enough to reach up and hold the strainer as you loosen from underneath;

Open up a pair of adjustable pliers and drop one handle down the drain, let the other handle become wedged against the sink as you turn; like shown in A below.

Or;

Open up a pair of slip joint pliers completely so that the handles come together at the ends. Stick handles of pliers up drain to hold cross bars while you loosen spud nut with tool; like shown in B below.