How to Sand Joint Compound How to Sand Joint Compound

What You'll Need
Joint compound
Level
120-grit sandpaper
Sanding block
Putty knife

Joint compound is used for many things around the home and large scale construction sites. You'll find joint compound used to fill in holes and to create flat surfaces. The most common thing to use joint compound on is drywall. In most cases, you would nail the drywall in place and then use joint compound to fill in the space where the nailhead sinks below the surface. Tape would then be applied along the seams. Drywall is usually painted, but if the joint compound isn't even with the surface of the drywall, the finished product will look sloppy. The paint will not cover the area completely where the joint compound is placed, and so the areas will be very noticeable. The information below will share with you how to properly sand joint compound so that you will never have to worry about unsightly finished drywall surfaces again.

Step 1–Application

The first step in sanding joint compound is making sure it is put on the drywall correctly. The biggest mistake that you can make is using too much of the joint compound. When you apply the joint compound, do so in an area that is no more than an inch or two. Use a putty knife to apply the joint compound. As you apply the compound, do so in a thin amount and use the putty knife to spread it so that is thin and the edges blend into the drywall.

Step 2–Drying Time

When you set out to sand down the joint compound, you need to make sure that it is dry first. If you try to sand the compound before it is dry, you will create a mess and will most likely have to do the job all over again. Always follow the instructions on the back of the container and add several minutes to the drying time listed because factors like heat and moisture can lengthen the time. Another solution is to choose a joint compound that changes color. As the compound dries, it will turn blue, signifying that it is ready to be sanded.

Step 3–Sanding the Joint Compound

Use the sanding block to start sanding down the joint compound. This will help to knock down the raised compound quickly. Use the sanding block at a slight angle and use even pressure as you sand against the way you applied the joint compound. If you applied the compound correctly, then sanding it will not take very long. Switch to the sandpaper when the compound is looking flat. Use the level between sanding in order to check that the joint compound is flat. This will take several times to get right. In most cases, you will be sanding the joint compound, reapplying it and sanding again, and then doing these steps a third time before you are actually finished. Make sure you use the level between layers to maintain the flat surface.

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