Mudding & Taping Drywall
You’ve put your drywall up. You’ve made sure that everything is aligned. Don’t forget to make sure the sheetrock does not overlap on the corners. The sheetrock should match the edge of your stud on both sides of the corner. And make sure you leave an empty triangle of space on the corner.
This enables your corner bead to sit flush on your wall and keep it from rocking back and forth and looking uneven.
While the first part of the drywall process requires a little muscle to get everything up and ready, the mudding and taping portion is where your creative skills come into play.
Begin by filling in all of the gaps that may have emerged at the seams between the pieces of sheetrock. Use a compound that isn’t going to shrink when it dries. If you don’t, there will be too many layers.
Make sure all of the joints between the drywall panels disappear so that the walls and ceilings are perfectly smooth. Use a small and large drywall knife and a swivel-head pole sander.
The key is to properly bead the tape and feather out the compound to an imperceptible edge. Brace the outside corners by making a bead gap, which helps you figure out if you’re using enough mud.
Next, place the tape over the seams. The key is to get it straight and be on the lookout for any air bubbles. Place a thin layer of mud over the joints (this will keep you from sanding all day).
Flatten the surface of the wall as much as possible. Make sure you have long tapers from the corners and thin layers from the seams.
Apply more mud than is necessary. You can fix it in the next step if there are large wrinkles in the mud. Remember, you can always take it down. But if you don’t apply enough here, you’re going to have to repeat this process.
Use the edge of your pan to make a thick bead of mud on the edge of your knife. In the first coat, use a 6- or 8-inch knife. You can use a 10-inch and 12-inch knife during the second and third coats.
The key is to not be heavy-handed with the mud. Use the knife at an angle with your wall in the corner you start with, and then gradually decrease the angle while you spread along your seam and the mud fills in the space.
Use your index finger to steady the knife and apply pressure. A good barometer is to repeat this until half of the seam is coated.
Go over the mud again. This time, use your thumb on the top end of the back of the knife to apply pressure to taper the top edge of your mud.
Next, use your middle finger to apply pressure on the bottom end of the back of the knife to taper the bottom edge.
Once all of your drywall is placed, mudded and taped, you’re ready for sanding. You’ll need three primary tools to proceed:
- A drywall grater
- A pole sander, preferably with a detachable head
- A sanding sponge
First, take the drywall grater and eliminate any large wrinkles in the mud. Remember to handle this process with some finesse, or you will revert to the mudding phase for some touch up.
Your grater isn’t going to smooth the mud. It simply enables you to quickly knock off any excesses that you applied during the mudding and taping process.
Next, take the head of the pole sander and smooth the mud as you go along. While this is a time-consuming process, it is not a highly complicated technique. You just want to use a motion that smooths out any streaks.
After you smooth everything out, you’ll be ready to texture the wall. Keep a wet/dry shop vac around to help fight the dust storm you will create with the sanding.
The Wet Sanding Approach
If you want to avoid the dusting of dry sanding, you may want to employ the wet sanding option. The primary value of wet sanding is for smoothing and feathering the ridge edges.
Wet sanding moistens the dried mud compound, which means it reactivates it and moves it to other parts of the wallboard.
For wet sanding, simply fill a bucket with lukewarm water. Dip and wring sponge.
While you might be tempted to wring out the sponge as much as possible, drywall sponges are exceptional at expelling water, so overwringing will be overdoing it.
Easing back on the wringing will leave enough water in the sponge to loosen the joint compound.
Next, knock down the high spots with the abrasive side of your sponge, and then slide the sponge in broad, circular strokes.
Don’t press too hard in any particular spot, as you don’t want to create depressions in the joint compound.
Wring out the sponge and switch sanding with the smooth side. Feather the joint compound outward from the joints, which will help reduce the visibility of seams after painting.