That twenty minutes is cheap insurance for a perfect line every time.

My last gym in Tampa had the same problem with mold on equipment. Humidity ruins electronics and makes any surface feel dirty. A clean desk is pointless if the air itself is damp and gross.

Seriously? You bought a no-name tool off an auction site and expected precision work. What did you think was going to happen for eighty bucks? That's on you for trying to cheap out on a job that needs real gear. Sometimes the old hand method is the only way to get it right.

You said it vanished for a day. Did anything look different when it came back?