Keep your other hand clear from the area in case the hammer misses the screw head.
You can purchase rust penetrant at most hardware and general stores. If you don’t have rust penetrant on hand, you can mix your own by combining equal amounts of acetone and transmission fluid. Regular WD-40 can help, but it isn’t as effective as specialty rust penetrants.
Hitting the screw with an impact driver and hammer may also help break up any remaining rust.
Stop turning the screw if you feel like you can’t keep the screwdriver in the screw head. The screwdriver may even slip out. This happens when the screwdriver begins stripping the screw.
You can use a regular kitchen or bathroom cleanser. You may already have some on hand. If you don’t want to mix your own paste, you can apply automotive valve grinding compound to the screw head instead.
If this doesn’t work, you can generate more force by turning the screw with a box-end wrench. Hold the screw in place with the screwdriver.
You can buy degreaser at a home improvement store, or you can make your own with vinegar or baking soda. Be sure to dispose of oily rags properly. Leave them to dry on a non-flammable surface out of direct sunlight. Throw them in the trash after they harden.
Wait to put the gloves on until after you clean the screw. This way, you won’t get any potentially hazardous degreaser on a good pair of gloves. Even if you are sure you wiped away all of the flammable chemicals, keep a fire extinguisher nearby just in case.
To avoid overheating the screw, keep the torch back so only the tip of the flame touches the screw. If the screw starts turning a cherry red color, move the flame away. You never want it to get this hot.
Heating the screw causes it to expand, while cooling it causes it to contract. Doing this rapidly increases the chances of the rust seal breaking.
If you find that you cannot remove the screw later, you can always try heating and cooling it again.
Make sure the screw is completely cool to the touch. You can test it by holding your hand over it. If you feel heat coming from it, add cold water.
You may need to apply penetrant a few times before the screw comes free. Keep twisting the screw back and forth so the penetrant soaks in.
Test the wheel by turning on the rotary tool. The wheel should spin freely at a consistent speed.
An ideal slot creates a tight fit for the screwdriver so you can turn the screw with maximum force.
If the slot is too small, you can widen it with the rotary tool. If the slot is too big, you may not be able to remove the screw this way unless you can find a larger screwdriver. Some screws will still be rusted in place even after you cut a perfect slot. Use heat to remove them.
