How do I punch Andair fuel valve screw holes?

[sritchie]

I recently had to change out the flanges on my Andair duplex fuel valve. The new flanges have little holes for me to punch out the sides of the screws once they're tight, but I'm having trouble figuring out the best way to hammer a punch into the hole and have it actually mash the side of the screw instead of just slipping off the screw and enlarging the hole.

Any ideas?

[terrye]

I used a sharp manual center punch and a hammer. Secure the valve so it doesn't move around (as in a vice, but be gentle). Once the screw is fully tightened, just use the center punch on the edge of the screw next to the relief in the housing. The screw head should then be deformed into the relief in the housing so it is unable to unscrew itself.

[sritchie]

Ah, nice. Being careful about where to put the punch and angling toward the hole slightly after the first few taps worked great. Thank you!