Ever had to paint a small part that’s still on the car and wanted an
easy and quick way to mask off the surrounding area from over spray?
Simply use aluminum foil! It’s cheap, quick and can easily be molded to
fit odd shapes, especially in the engine compartment. Use as many
pieces as necessary to cover the possible over spray area. Just be sure
there are no gaps or places the overspray can get under the foil. When
the paint is dry the foil comes off easily with no sticky mess from
tape. I’ve used this trick to touch up exhaust headers before a car
show and always get great results. Tip courtesy of Tom Weincek.