TL;DR
Wet caulk wipes off a gun or a blade in seconds, and cured caulk has to be peeled or scraped, so this whole job is decided in the two minutes after you set the tool down. A gummed plunger rod is the usual reason a caulk gun stops feeding smoothly.
Know what you are cleaning off
Latex and acrylic caulks are water-based. Wet, they wipe off with a damp rag. Cured, they peel with patience.
Silicone caulk does not clean up with water at all. Wet silicone wipes off with a rag and a little mineral spirits, and cured silicone is a mechanical removal job.
Polyurethane sealants are the toughest of the three. Clean them wet with mineral spirits and expect a real fight once they cure.
Construction adhesive follows the same pattern as polyurethane. Read the tube label, because it names the cleanup solvent.
The two-minute window
Wipe the gun nozzle, the frame, and the plunger tip the moment you finish a bead. A rag and thirty seconds is the entire job.
Cap the tube or push a nail into the nozzle so the tube itself does not cure shut. That is a separate but related win.
Wipe the plunger rod along its whole length while it is out. Caulk that dries on the rod is what makes the gun ratchet roughly later.
If the caulk is water-based, a damp rag is enough. If it is silicone or polyurethane, use a rag with a little mineral spirits and ventilate the space.
The same timing logic governs tile work, where the window is even shorter, as covered in how to clean tile tools before the mortar sets.
How do you clean dried caulk off a caulk gun?
Peel cured caulk off the gun mechanically, since solvents do very little to fully cured silicone or polyurethane. Flex the frame and pick the beads off with a fingernail, a plastic scraper, or a putty knife, then clear the plunger rod with a wire brush and finish with a drop of light machine oil on the rod and the trigger pivot.
Cured caulk on a smooth metal frame usually peels in strips once you get an edge started. It bonds poorly to bare metal.
For the ratchet teeth on the plunger rod, a wire brush is the right tool. Debris there is exactly what makes the gun skip.
A caulk softener product exists and can help with heavy buildup, but it needs gloves, ventilation, and a careful label read. Never combine it with any other product.
Do not soak an entire caulk gun. The spring and the ratchet plates need to stay dry and lightly oiled, not flushed.
Putty knives, scrapers, and joint knives
Wipe joint compound off a taping knife before it sets. Dried compound on a blade edge leaves ridges in your next pass.
Warm water and a scrub with a stiff brush handles water-based compound and latex caulk. A second knife makes a good scraper for the first one.
Dry the blade immediately and completely. Carbon steel taping knives rust fast, and a rusty blade transfers stain into light joint compound.
Wipe the blade with an oiled rag before storage, then wipe the oil off before the next use. If rust has already started, the methods are in how to remove rust from hand tools.
Stainless blades resist rust but still need the compound off. Buildup along the shoulder is what ruins the flex.
Keeping edges straight
A putty knife works because its edge is straight and its flex is even. Both are easy to ruin.
Do not use a putty knife as a pry bar or a chisel. A bent blade never lays a smooth pass again.
Store knives flat or hanging, not loose in a bucket where the edges get nicked. A bucket is where good blades go to die.
Dress a nicked edge with a file or a sharpening stone, holding the blade square. Take off as little as possible.
The gun mechanism itself
A caulk gun that will not hold pressure usually has worn or gummed ratchet plates, and cleaning them often restores it.
Release the plunger fully, pull the rod out if the design allows, and clean both the rod and the plates with a brush.
Add one drop of light machine oil at the trigger pivot and along the rod, then work the mechanism several times and wipe the excess.
Dripless guns have a small pressure-release mechanism at the plunger that gums up with cured caulk. Clearing it is often the fix for a gun that will not stop oozing.
If the frame is bent or the ratchet teeth are worn round, the gun is finished. Basic guns are inexpensive enough that this is not a hard call.
Disposal and storage
Cured caulk scraps and used tubes go in regular trash. Wet caulk and uncured sealant do not go down a drain.
Used mineral spirits is household hazardous waste. Let it settle in a sealed jar, pour off the clear solvent to reuse, and take the sludge to a drop-off. Confirm your county's current site and hours before going.
Rags used with solvents or oil-based products are stored flat until dry or in a sealed metal container, never wadded in a bin.
Store caulk tubes upright and capped, somewhere that does not freeze. A garage that drops below freezing ruins water-based caulk, and the same shelf discipline that helps here helps with paint supplies, as covered in how to clean paint rollers, covers, and trays. For the rest of the shop, see our guide to cleaning tools, yard gear, and hobby equipment.
FAQ
What removes dried silicone caulk from tools?
Mechanical removal, primarily. Cured silicone does not dissolve, so peel it, pick it off with a fingernail or a plastic scraper, or cut an edge free with a razor blade held flat. A commercial silicone softener can loosen heavy buildup with gloves and ventilation, but patience with a scraper handles most of it.
How do I fix a caulk gun that will not push caulk?
Check the plunger rod and ratchet plates for cured caulk and debris, since that is the usual cause. Release the plunger fully, brush the rod and the plates clean, add a drop of light machine oil at the rod and the trigger pivot, and cycle the mechanism. Replace the gun if the teeth are worn round.
Can I use water to clean a caulk gun?
Only for water-based latex or acrylic caulk, and only while it is still wet. A damp rag on the frame, nozzle, and plunger rod is enough. Do not soak the gun, since the spring and ratchet plates should stay dry and lightly oiled rather than flushed with water.
How do I clean joint compound off a taping knife?
Wipe it off before it sets, then wash the blade in warm water with a stiff brush, paying attention to the shoulder where the blade meets the handle. Dry it immediately and completely, since carbon steel blades rust quickly and rust stains light joint compound on your next pass.
Should I oil putty knives and scrapers?
Wipe carbon steel blades with a lightly oiled rag before storage, then wipe the oil off before use so it does not contaminate compound or paint. Stainless blades do not need it. Storing knives flat or hanging rather than loose in a bucket does more for edge life than any coating.
How long can caulk sit in a gun before it cures?
Once opened, a tube typically stays usable for a few days to a couple of weeks if the nozzle is sealed with a cap or a nail and the tube is stored somewhere that does not freeze. The gun itself should be wiped clean right away regardless, since caulk on the rod is what ruins the mechanism.
Trim and caulk work makes a mess well past the room it happens in. If the rest of the house needs attention afterward, our house cleaning services can take it. Every home is different, so the real number depends on size, condition, and what you want covered. Get a quote and we will walk you through it.