Ever try holding a piece of trim against a wall and finding that the nail you chose doesn’t quite hold the wood? Or worse, splits it apart? That’s the gap between “Rough” and Finished work. Above is the breakdown for gauge (thick) vs behavior. Knowing which holds best and why make for clean carpentry.
The first one is an eighteen-gauge brad nailer, which is a good choice for beginning because it’s such a multipurpose gun. Eighteen gauge goes into a small head that has a very small hole, requiring typicaly only a dab of putty (or no putty at all). You use this nail size for things like cabinetry; you’d want the nail to be hidden on baseboard.
How to Choose the Right Nail
But there’s a catch. Because the wire is thin, the holding power isn’t great. If you’re nailing something heavy or using soft wood, the eighteen-gauge nail may back out over time. And that’s a frequent misstep. People assume that smaller is always better for finish work, but smaller is also less grip than others.
When the stakes are higher, step up to fifteen- and sixteen-gauge. And as the infographic shows, those beefier wires offers far greater holding power. A fifteen-gauge nail offers maximum pull resistance in its class and can absorbs being driven by an angled nailer. Here’s what it’s good for: Crown molding and door jambs, where impact and gravity is very real factors.
The downside? As you might guess, the bigger wire means a bigger entry hole which you’ll have to fill and then paint and/or sand. Strength comes with more prep work.
At the opposite end of the spectrum, pin nails; like twenty-three gauge (are nearly imperceptable). They is great for beading and other veneers, where even the slightest dimple will ruin the look. The bad news? These has to be glued into place. The nail only serves as a clamp until adhesive sets; no amount of pin nail alone will hold anything substantive in place.
Choosing the right nail length is as important as choosing the right gauge. And the general rule is to have the nail go into the backing material at least as far as thickness of your trim. If it’s a quarter-inch piece of veneer, a short pin will do it. If you’re hanging a thick baseboard, you want nails long enough to grip the studs or wall plate firm.
To avoid under-driving, where there’s a proud nail head that spoils the profile, or over-driving, which blows out the face of the wood, the chart points out standard lengths for each gauge. This helps avoid either end of spectrum. Balance is everything.
The air pressure is an important part of the process. You don’t need maximum PSI, because high pressure can causes splitting in hardwoods. Hardwoods such as maple and oak will split under high air pressure. This isn’t good for fine finish work. Set your compressor low and adjust the depth-of-drive dial on tool. You’ll be looking for the head to just be below the surface. If you’re hearing cracks, ease back off of pressure. Two passes are better than a split piece of wood and starting all over again.
You should also consider what kind of nail to use. You’ll want to use stainless steel (more expensive), galvanized (will react with tannins) or a standard bright steel nail (rusts when exposed to moisture). If moisture enters, you’ll end up with unsightly rust stains that can bleed right through your paint job years down the road. Galvanized nails also do better in humid conditions; however, these reactive woods such as cedar require an exterior grade coating.
These are nails. Match the fastener with the force it has to endure. Delicate crafts requires fine pins. A heavy trim requires a heavy nail. Consider each setting (length, gauge, pressure) together. This helps you turn an unruly collection of choices into a cohesive plan. It’s when you begin allowing the tool to do its thing instead of wrestling it for control.
And then…trim is up and intact. Looks like it was never nailed at all. Exactly. Clean lines, strong holds, and no tell-tale signs of your effort. You should of checked everything first.
