About Wall Repair Compounds

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We use two types of joint compound for finishing new drywall seams and repairing drywall and plaster surfaces: ready–mixed joint compound and setting–type.

Ready–mixed Joint Compound

Ready–mixed compound is a premixed mud used mostly for finishing drywall seams but it's also well suited for repairing minor damage to drywall and plaster surfaces. It is very soft and extremely easy to sand. In fact, a small patch of dry ready–mixed compound, such as over a nail pop, can be remove completely in just a few strokes of 120 grit sandpaper. This can be a problem when you remove more of the patch than you need to and have to redo the repair to smooth out the wall again.

Setting–type Joint Compound

Setting–type joint compound comes as a fine powder, it is very well suited for making thick applications when finishing metal drywall corner bead, repairing water damaged plaster or other deep wall damage.

Setting compound is similar to concrete in that it sets after mixing with water due to a chemical reaction, rather than drying from evaporation like ready–mixed does. Because of this, setting–type can be much harder to sand than ready–mixed joint compound. To make sanding easier the manufacturers came up with softer formulas, Easy Sand Durabond® is one of these.

While this newer product is easier to sand than the original it is not as versatile. Don't for instance, try to skim coat with Easy Sand Durabond. It tends to curl up and fails to bond well when applied in very thin coats. Because of this, we don't recommend these softer setting compounds. Instead we suggest applying regular setting compound in thin coats to make it easier to sand.

Using Joint Compound

Start by making normal repairs to deep holes and gouges with thick coats of setting compound. Let each coat set well before applying the next. Fill holes almost completely and then finish the repair with several thin, skim coats to build up a smooth surface. This approach works well for repairing cracks as well. These thinner applications of setting compound will be as easy to sand as dry ready–mixed compound.

Another choice if you really need easy sanding is to use ready–mixed joint compound to apply the finishing skim coats. This will work well in most cases, although for a hard, plaster–like finish you will have to stick with a setting–type joint compound. Also if you are doing repairs to water damage, ready–mixed compound my bubble up or otherwise fail as it is affected by any moisture in the surrounding surface.

If you are dealing with water damage or other type of contamination, you will want to coat the surface surrounding the repair area with primer–sealer. If the contaminated surface is not sealed it will corrupt the bond between the new joint compound and the wall or ceiling surface. See Repair Bubbling Paint for more about priming and how to avoid bubbling in newly applied joint compound.