Updated: Aug. 12, 2020
The basics
Trim nailers are categorized by the thickness or “gauge” of the nails they shoot: The bigger the gauge number, the smaller the nail (seems backward, doesn’t it?). Nailers that shoot the biggest trim nails—15 and 16 gauge—are usually called “finish nailers.” Midsize 18-gauge nailers are called “brad nailers.” The smallest nailer, the 23-gauge, is usually called a “pinner” or “micro pinner.”
15-gauge finish nailer
This is the gun I usually grab for nailing large 3/4-in.-thick baseboard and trim. It’s also a good choice for more demanding jobs like nailing doorjambs or stair treads. These nailers have a large piston, and because of the extra bulk, often have angled magazines so you can get into tight spots. Name-brand 15-gauge nailers, which handle nail lengths up to 2-1/2 in., start at less than $200.
16-gauge finish nailer
Like 15-gauge nailers, most 16-gauge guns shoot nails up to 2-1/2 in. long and are suitable for thick trim. The main advantage of a 16-gauge gun is that it’s smaller and lighter. If you’re shopping for a finish nailer, I’d recommend the larger 15-gauge gun, simply because the fatter nails provide more holding power. But some carpenters disagree with me. You’ll pay about the same for a name-brand 16-gauge nailer as you would for a 15-gauge gun.
18-gauge brad nailer
If you plan to buy only one trim nailer, this is the size to get. I use mine more than all my others combined. It’s perfect for standard trim, furniture making and odd jobs around the shop. Models that shoot brads up to 1-1/4- in. are common, but I strongly recommend spending a few bucks more for a gun that can handle brads up to 2 in. long. Name-brand 2-in. guns start under $100.
23-gauge pinner
This is the nailer I use the least. Those tiny pins just don’t have enough holding strength for most jobs. But don’t get me wrong—there are times when pins are perfect, especially to nail small parts. My pinner, which cost a little over $100, shoots pins ranging from 1/2 to 1 in. long. That’s long enough for most jobs, though I occasionally wish I had a model that could handle pins up to 2 in. long, which would cost $225 or more.
Smaller-gauge nails usually come in packs that load vertically. 16-gauge nails usually come in packs that load at an angle.
I always found it difficult to keep parts aligned when screwing cabinets together. Then I discovered that a couple of shots with my finish nailer or brad nailer will keep the parts aligned while I drill pilot holes and drive screws for strong joints.
With a trim nailer, you can install tongue-and-groove paneling in a fraction of the time. Some carpenters use a finish nailer for this, but I like to use my smaller, lighter 18-gauge brad nailer, especially on ceilings. Brads don’t have the holding power of 15- or 16-gauge nails, of course, but I make up for that by shooting two brads into every stud or joist.
I do a lot of work in old houses. And hammering nails through those old plaster walls is a recipe for cracks. A trim nailer, on the other hand, drives nails instantly, without the repeated blows that can cause cracks. I like my 15-gauge nailer best for these jobs; the nails are stout enough to push through the hard plaster and long enough to bite into the framing behind it.
One of the best things about trim nailers is that you don’t have to worry about beating up the wood, unlike with a hammer. That means you can finish parts before assembly. I especially like to finish trim before installation, which gives me better results in less time. Just be sure that the soft rubber tip that came with your nailer is actually on the gun before you shoot.
Pins are tiny and headless, so they’re hard to see even before you fill them. Afterward, nobody but you will know they’re there.
I make a lot of gifts for friends and family. My pinner is the go-to tool for delicate assemblies like these and saves me the torture of gift shopping.
With a coat of slippery glue, parts will slide out of alignment while you’re desperately trying to clamp them. My solution is to tack the parts together with a couple of nails. That keeps the parts aligned while I apply serious pressure with clamps.
To eliminate measuring errors, I like to hold trim in place to mark the length. When the piece is too long to hold alone, I tack one end to the wall with a brad nail. Then I mark, yank the trim off the wall and remove the brad. (I use nippers to pull the brad through the back of the trim to avoid damaging the face of the trim.) That gives me an accurate cutting mark and only one extra nail hole to fill later.
Studs aren’t always located where we need them. When I need to nail trim where there’s no stud, I dab some construction adhesive on the back of the trim and then drive nails into the drywall at 45-degree angles. That holds the trim tight against the wall while the adhesive cures. This “trap nailing” technique works fine with brad nailers and even better with finish nailers.
Starting a nail with a hammer takes both hands and that limits your reach. So I used to spend more time moving my ladder than driving nails when I was installing crown molding. A trim nailer, on the other hand, lets me reach way over to shoot a nail. And using a bench, rather than a ladder, lets me nail off even the longest runs in only two or three moves. My aluminum bench (Werner AP-20) cost well south of a hundred bucks online.
My only gripe about trim nailers is “blowout.” Careless aim is sometimes the cause, but other times the nail inexplicably takes a turn inside the wood and pops out. When this happens, I grab a hammer and try to drive the nail up so I can grab the head with pliers and pull it out. This often works with 15- or 16-gauge nails, but 18-gauge brads almost always bend when I try to drive them back. In that case, my only solution is to grab the nail with pliers, bend it back and forth until it breaks off, and sink the remainder of the nail with a nail set.
