Wet Areas – most caulking is not recommended for surfaces exposed to moisture. Instead, you'll need bathroom caulk that is silicone-based as it resists water after it's sealed. Painter's caulk is for indoor dry surfaces that can be painted over. Exterior Surfaces – painter's caulk is for interior use.
When painting indoors, painter's caulk is mostly important for aesthetic reasons. It provides a smooth, gap-filling bond that adds a professional look on wall joints, baseboards, and crown molding. Paintable caulk is also used for countertops and other wooden trim.
Latex Caulk or Acrylic Latex Caulk (Also known as "painter's caulk") - This is probably the most common type of caulking that you see used by everyone. It's inexpensive, paintable, readily available almost anywhere, and it's soap-and-water-cleanup makes it very easy to work with.
But the main difference is in their makeup, which dictates how they are used. Both are waterproof and flexible, but a silicone sealant has more silicone in it, giving it more flexibility. Decorators/painters' caulk has less silicone, so it is not as flexible but can be painted over.
Many manufacturers make different product lines specifically for certain tasks. Consider where you will use the caulk and check the label to find the manufacturer's recommendations for use. Products with silicone work best in water-prone areas. Latex acrylic is suitable indoors for use with wood on drywall.
Applying a new layer of caulk to an old layer of caulk isn't recommended, but it is doable if the old caulk is still in relatively good condition. Damaged, cracked, and worn caulk won't provide a firm surface for the top layer of caulk, often leading to cracks and damage in new caulk.
For interior door, window and trim projects, acrylic latex caulk is usually a good bet. Use it for multiple projects, from installing wood paneling without nails to quickly filling in small drywall holes and cracks. Experts advise acrylic latex caulk is the best choice for baseboards.
Silicone caulk is excellent at water sealing and flexibility so it has its place in construction. There are two main places it never should be installed, wood or any painted surface.
Cracking - caulk is unfortunately prone to cracking, which sometimes occurs when the caulk is not flexible enough for the surface it is filling. Crazing - when paint is applied over caulk, it can sometimes lead to the paint to peeling & flaking.
What kind of caulk do you use in the bathroom? The best caulks for tubs, sinks, or shower stalls come in tubes labeled “Tub and Tile” or “Kitchen and Bath.” These are either acrylic latex or silicone compounds that have been chemically tweaked to resist mildew and to stick to smooth, nonporous surfaces.
Caulk Bead Cracking
The movement and/or change in joint size is a result of moisture reduction and shrinking of the wood fibers and, most commonly, it results in hairline cracks in caulk beads and painted joints, as well as separation in the panels of doors.
DAP Dynaflex 230 Premium Elastomeric Sealant
Its formula is specially designed to resist cracking and improve flexibility over other latex-based caulks. After application, it should be ready for painting in about 2 hours. During the test, we found Dynaflex 230 very easy to apply.
Unlike typical decorators' caulks, the Dunlop Flexible Acrylic Filler can be overpainted with any oil or water-based paints without the need to spot prime and the painted surface will not craze or crack and remain smooth even after painting.
Wet Areas – most caulking is not recommended for surfaces exposed to moisture. Instead, you'll need bathroom caulk that is silicone-based as it resists water after it's sealed. Painter's caulk is for indoor dry surfaces that can be painted over.
Acrylic Caulk (also known as latex caulk)
It is easy to work with, and you can smooth the joints with your finger to create a clean finish. Old acrylic caulk is easily removed – just cut it with a utility knife or pull it.
In general, caulk should be applied before painting if the caulk line will be visible once the paint job is complete. This includes caulk lines around windows, doors, and baseboards. On the other hand, caulk can be applied after painting if the caulk line will be hidden by trim or molding.
GE Painter's Caulk is a high quality caulk. It is an all purpose, indoor outdoor, siliconized acrylic latex. It adheres to common building material well. it is strong, easy to use, and waterproof.
It can, so it's important to lay your caulk lines correctly the first time in order to prevent having to lay a new line over one that has shrunk.
Similarly, you should avoid caulking the bottom edges and joints of your fascia trim and soffits. Any water that doesn't get into the gutters can be trapped in these areas if they're sealed off.
While latex caulk is less expensive and easier to work with, silicone is more durable under extreme weather conditions, and can be used as a binder as well.
As previously mentioned, silicone sealant is waterproof—so the mould doesn't actually grow on the surface of the product itself. Mould needs a damp surface on which to develop, and this is simply not possible on the sealant itself.
Hercules® Plumbers Caulk™ is a commercial-grade, easy-to-use, single component, siliconized acrylic-latex non-sag caulk. It forms a flexible, durable, mildew and UV-resistant waterproof seal on interior and exterior surfaces.
Consider Polyurethane
In terms of performance, polyurethane caulk is just plain better than acrylic caulk. Polyurethane caulk sticks better and retains its flexibility longer. The downside is that polyurethane caulk is more difficult to apply neatly, harder to smooth out and tough to clean up.