Squirt a dollop of valve grinding compound into the head of the screw. Then jam in the screwdriver and turn.
No matter how simple the repair, it seems like there’s always one stuck screw. You try to muscle your way out of the jam, but all that does is cam out the screw head slots.
It doesn’t have to be that way. Here are a few tricks to coax out a stubborn Phillips screw. At the first sign of trouble, spray the screw with rust penetrant (Liquid Wrench and PB Blaster are two really good brands). Let the penetrant work for at least 15 minutes.
Then spray it again and tap the screw head dead-on several times with a hammer. Then try the screwdriver again.
Next, apply valve grinding compound. The compound contains a fine grit that helps the screwdriver bite into the head.
Still stuck? Try stronger techniques
Hold the body of the impact driver to prevent it from turning. Then hit the end with a serious blow. If the screw still won’t budge and the surrounding surfaces can tolerate some heat, aim a lighter flame directly onto the screw head.
Then douse it with cold water before trying it again. Still stuck? Invest in an impact screwdriver.
Stripped the head? Cut a new one
Slice a deep groove into the screw head with a cutting wheel and rotary tool. Make it wide enough to accommodate your largest flat-blade screwdriver.
If you’ve stripped out the head, cut a new slot with a straight-groove rotary tool. Then crank it out with a flat-blade screwdriver.