Step-by-Step Instructions and Pictures: How to Use a Trim Nailer Gun

Underdriven Nails: Adjust the Pressure and Nail Length
Problem: Nail Not Set
Solution: Increase Pressure

Nails that don’t set, or that are left sticking out, are usually the result of pressure that’s too low, a nail that’s too long or an improperly adjusted nail gun. If the nail is sticking way out, try increasing the air pressure to the maximum allowable for your nail gun (90 to 100 lbs., or check your instructions). If the nail still won’t set, try loading shorter nails or brads.

The nosepiece on some nail guns is adjustable to help control how deep the nail is set. Use this in conjunction with pressure adjustments to fine-tune your nail gun until the head of the nail or brad is slightly recessed. Keep a nail set handy for the occasional protruding nailhead.

Don’t bother pounding in nails that protrude more than 1/4 in. They’ll just bend over and dent the trim. Instead, grab the shank and bend it back and forth until it snaps, or use a side-cutting pliers to cut the nail near the surface. Then recess the rest with a nail set.