Spackling is sometimes mistakenly used as a skim coat. But spackling isn't made for this application – it dries too quickly, doesn't spread smoothly and is hard to sand* to a fine finish on large areas. So, when looking for a smooth, paintable surface, let the spackle do its job: repairing small damage.
The really important thing to know about spackle is that it can't be used for skim coating (that is any area with an exposed face) because the molecules are too far apart to offer sufficient surface area for adhesion (I asked the manufacturer).
You can use drywall mud. I have done it many times. You can also use spackle. If the area is small spackle is the way to go. If you are skimming most of the wall just use mud. Besides cost the big difference is that spackle doesn't need to be primed and drywall mud does.
Simply painting over the spackle spots often allows them to bleed through the coat of paint in a manner that is commonly referred to as “flashing.” It takes a few extra steps after repairing your wall to ensure that the spackle spots can be well-hidden and unobtrusive.
The application of drywall mud over paint requires precision and patience. Starting with a thin first coat, the mud should be spread evenly across the surface using a trowel, ensuring all imperfections are filled and the surface is uniform.
Typically, paint that stops sticking to the subsurface results from the presence of water. Extensive water vapor in the indoor air can cause paint to peel, and water in the drywall or plaster can come from a leaking water source.
However, lightweight spackling should be used only for smaller nail-hole repairs and dents, and not for medium-size or large repairs.
Using spackle to repair holes is ideal as spackle does not shrink as much as joint compound. Mud shrinks after applying, requiring multiple layers of application. Spackle does not shrink as much as joint compound.
USG Sheetrock® Brand All Purpose Joint Compound is a best-in-class solution for embedding tape with superior filling and finishing qualities and is an excellent choice for skim coating.
Can I skim with exterior filler? Yes! Our Exterior Skimcoat Filler range comes in powder or ready mixed version. It is designed for smoothing old or damaged render and can also be used to skim over masonry locally.
Skimcoat, putty, and patching compound—are these all the same? Some may think yes but the correct answer is no, they are not. Though they all are used to fix imperfections on concrete, they do not all pertain to one thing.
High humidity can slow down the drying process because spackle needs to lose moisture to set right. But air movement, especially when it's warm, can make spackle dry faster.
Spackling products work well for small holes in drywall. Plaster walls should be repaired with a plaster product.
Sometimes when you don't skim coat new drywall, you can see where the paint absorbs differently into the joint compound and drywall paper leaving the tape joints very visible especially with paint that has a sheen such as semi-gloss or gloss paints. This is called flashing or photographing in the painting world.
Spackling is sometimes mistakenly used as a skim coat. But spackling isn't made for this application – it dries too quickly, doesn't spread smoothly and is hard to sand* to a fine finish on large areas. So, when looking for a smooth, paintable surface, let the spackle do its job: repairing small damage.
Like it's cheaper than buying paint at Benjamin Moore. The supplies you need to skim coat your walls include: joint compound, a sanding block, a bucket for mixing, a drywall knife and a mud pan. (I also recommend a drill with a mud mixer paddle attachment).
All-Purpose Spackle All-purpose spackle is used for all standard repairs in drywall, such as cracks, holes, dents and dings. It contains gypsum powder, which allows it to harden to a similar consistency to drywall.
Patchy paint can result if paint has been applied unevenly. Patchy paint can be down to a variation in surface absorption. Walls might appear patchy if they have variation in texture. Using paint that is not fully mixed can cause a patchy appearance.
Fast-drying spackle may take only a few minutes to dry but it isn't wise to start sanding or painting for at least another 1-2 hours. Normal spackles will take 1-2 hours to fully dry but we don't recommend sanding or painting until a full 24 hours has passed and the drying is complete.