I've used a lot of caulk guns. Some on the ground, most on ladders, a few on roofs I'd rather not think about. Here's what I know: the gun is half the bead. A good one delivers caulk smoothly, stops when you stop, and doesn't wear out your hand. A bad one jerks, oozes, and turns a ten-minute job into a cleanup. The difference usually costs less than a pizza.
Anatomy of a gun and cartridge
Ratchet vs. smooth rod
This is the big one.
Ratchet guns have a notched rod. Each squeeze of the trigger catches a notch and shoves the plunger forward one step. They're cheap and they work, but the flow tends to come in pulses, and they don't release pressure on their own. When you stop squeezing, the tube keeps pushing caulk out until you rotate the rod (so the teeth face up) or pull it back. Beginners with ratchet guns are the reason paper towels were invented.
Smooth-rod guns use friction plates that grip a plain steel rod. The flow is smoother and easier to control, and most smooth-rod guns include some kind of pressure release. For almost everyone, this is the right kind of gun.
What "dripless" really means
A dripless gun automatically backs the plunger off a little when you let go of the trigger, so the pressure on the tube drops and the flow stops. "Dripless" is a slight exaggeration: thick sealants and tubes with trapped air can still push out a bit after you stop. But compared with a ratchet gun, it's the difference between a drip and a flood. Pair it with the habit of easing off the trigger just before the end of a run, as we describe in how to lay a perfect bead, and you'll hardly notice.
Thrust ratio, and when it matters
You'll see numbers like 10:1, 12:1, 18:1, or 26:1 on the package. That's the thrust ratio: roughly how many pounds of push reach the tube for every pound of squeeze on the trigger. It's a trade-off.
- Lower ratios move more caulk per squeeze and feel quick and responsive. They suit easy-flowing materials like acrylic latex and most silicones.
- Higher ratios push harder but move less caulk per squeeze. They make thick materials manageable: polyurethanes, construction adhesives, butyl, and anything you're gunning out in cold weather, when every sealant gets stiffer.
If your hand is sore after one tube, your ratio is too low for the material. If you're squeezing over and over to lay a short bead of latex, it's higher than you need.
Open cradle or closed barrel?
Most homeowner guns have an open cradle, a half-round frame the cartridge sits in. It's light and makes loading easy. A closed barrel gun wraps the whole cartridge in a tube. The barrel supports the cartridge so it can't bulge or split under high pressure, which matters with thick materials, and it's required if you use bulk sealant or foil "sausage" packs.
Features worth paying a little for
- A built-in seal-puncture wire that folds out from the frame. You'll use it on every tube.
- A rotating cradle or barrel, so you can turn the nozzle to match the joint without twisting your wrist.
- A ladder hook, for hanging the gun on a rung instead of dropping it on the neighbor's car.
- A comfortable, full-hand trigger and a metal frame that doesn't flex.
The tip-cutter hole in the handle is a nice idea that tends to crush the nozzle. Cut tips with a sharp utility knife instead.
Cordless and pneumatic guns
Battery-powered guns use a motor to drive the plunger at a speed you set with a dial. The flow is perfectly steady, which makes for very even beads, and your forearm gets the day off. They're heavier and they cost a lot more, so they make the most sense for big jobs like re-caulking a whole house of windows or sealing siding. Pneumatic guns do the same thing using shop air and are more common in production settings.
Sausage packs and bulk
Pros often buy sealant in foil-wrapped "sausages" instead of cartridges. They fit in a closed-barrel gun, hold more sealant than a standard tube, and leave behind a small crumpled wrapper instead of a plastic cartridge. If you're doing a large exterior job with a professional-grade sealant, ask whether it comes in sausages. For most homeowner projects, cartridges are simpler.
Squeeze tubes
Small squeeze tubes, usually holding a few ounces, need no gun at all. They're great for quick fixes: a gap around a faucet, a short strip of backsplash, a single window pane. For anything longer than a couple of feet, a gun gives far better control, because hand pressure on a squeeze tube is hard to keep steady.
Cartridge sizes
The standard cartridge holds about 10 fluid ounces (the familiar 10.1 fl oz, roughly 300 mL) and fits every standard gun. Some construction adhesives and sealants come in large 28-ounce cartridges that need a large-frame gun. To estimate how many tubes a job will take, use our tube calculator.
Taking care of your gun
Wipe off wet caulk before it cures, especially on the pusher plate and cradle. Keep the rod clean and dry. On a smooth-rod gun the friction plates need to grip the rod, so don't oil it; if the rod starts slipping, clean off the old caulk and grime. Store it somewhere dry so the rod doesn't rust. A decent gun, looked after, will outlast a lot of houses.
What I'd buy
- Most homeowners
- A dripless, smooth-rod gun with a thrust ratio somewhere around 10:1 to 18:1, a puncture wire, and a ladder hook.
- Thick sealants or cold weather
- A higher-ratio gun, 18:1 or more, ideally with a closed barrel.
- Big exterior jobs
- A cordless gun, and consider sausage packs if your sealant comes that way.
- One small fix
- A squeeze tube. No shame in it.