How to Finish Drywall: First Coat
Finishing drywall is not as difficult as one may think yes it can be a bit messy, yes it does require a steady hand but mostly patience’s. For most drywall finishers to become efficient in their trade they will need to spend about six months of on the job training to acquire the skills necessary to do an excellent job. With a good attitude, a little patience’s, and the wiliness to learn from others and your mistakes, you can be confident in your ability to do an excellent job.
Drywall finishing commonly called tapping is simply the process where the screws, seams, and corners are concealed with three coats of joint compound then sanded to a smooth finish ready for paint, texture and or wall paper. The first coat is called the embedding coat, the second is the filler coat and the third is the finish coat. Each coat is applied a little wider than the previous coat with the edges feathered to provide a smooth surface. I’ll explain the application of each coat a little latter but first you need to know what needs to be taped or finished.
Before you begin tapping there are few things that you should do. First clean your work area by removing any debris such as pieces of drywall, tools, extension cords, vacuum or sweep the floor of any dust along the bottom of the wall. This will help remove any trip hazards and prevent any chunks of drywall and dust form being pulled into your mud. Second make sure all panels have been secured to the framing, any electrical boxes and holes have been cut out and that all outside corner bead has been installed. Lastly make sure the room temperature is around 55 degrees and that there is plenty of air flow either from an open window or a fan. This will aid in the drying and setting of the joint compound.
Now that your work area is free of debris and trip hazards let’s begin the process of finishing the drywall. First you need to decide which type of joint compound to use. As explained in the Service & Product page under the heading Joint Compounds there are two types of joint compounds setting types or drying types. For the coat I would suggest using the setting type, if you prefer you can use the all-purpose ready mix joint compound. The mixing instruction if using the setting type in powdered form is also explained on the Service & Product page under the heading Joint Compounds.
Pre-Fill Gaps & Damaged Areas
Here we go, the very first thing I do before I start finishing the seams is to pre-fill any gaps that are more than 1/8" of an inch wide between panels and at the ceiling. Repair any damaged areas of the panel such as busted out inside corners, outlet- box openings, busted out areas along the floor, do this for all walls in every room that are to be finished. Once I have pre-filled and repaired any damage areas I mud or first coat all the screw heads this way you don’t mess up any seams. I do this in every room.
First Coat Screw Heads
To mud the screw heads you only need a thin layer of joint compound to conceal the screw heads, and it’s easiest to mud a row of two or three screw heads in a single strip rather than individually. Using a 6" mud knife, apply just enough pressure to fill the indentation and leave the face of the drywall panel covered with a very thin film of compound. Don’t try to fill the indentation with on thick coat, remember you have to sand, the thicker the mud the harder it is to sand and to achieve a smooth surface. Applying the compound in three coats and tapering the edges brings the indentations level with the panel and requires only minimal sanding. Apply the second and third coats at the same time you second and third coat the seams. Remember to allow 24 hours between coats.
Second & Third Coat Screw Heads
Second and third coat of screw heads is the same as the first coat the only difference would be that each time you mud the screw heads would be to scrape any debris or thick mud from the screw heads before you apply the second and third coat, remember to allow each coat to dry a full 24 hours.
First Coat Tapered-Edge Seams Between Panels
Now that you have first coated all of the screw heads it is time to first coat the seams. Note that there are two types of seams, tapered-edge seams (seams between two panels with tapered edges), butted –seams (seams where non tapered panel ends are joined together). We will first discuss the tapered-edge seams between panels. These seams will take considerably longer to first coat because they require the application of joint tape as well as joint compound. There are two types of joint tape and both are discussed in the Service & Product page under the heading Joint Tape.
I usually use self-adhesive fiberglass joint tape rather than the paper tape on the tapered-edge seams between panels. When using the mesh tape apply the tape to all seams in the room before applying the joint compound. Do this by centering the joint tape over the seam starting at one end and pressing the joint tape firmly against the seam so that it lies flat without wrinkles, pulling and pressing the joint tape the length of the seam, cut with a utility knife or with the edge of the mud knife.
Using a 6" mud knife apply joint compound the entire length of the seam and into the corners. Now switching to a 10" mud knife place a small amount of joint compound onto the mud knife (the length of the knife), place the knife into the corner, center over the seam. Using even pressure with the knife held almost flat against the panel pull the knife along the joint, smoothing the compound with the back edge leaving a layer of compound that just covers the tape and fills the recessed areas of the tapered seam. The edges should be fairly smooth and feathered. If a lot of compound builds up in front of the mud knife and pushes out around the sides as you smooth the seam, either you have too much joint compound on the seam or you’re taking too much off. When you have finished the seam, the joint compound should be about 3/16" thick in the center and 6" wide from one tapered edge to the other. Remember this is only the first coat, just make sure that the joint compound is not too thick and that there is not a buildup of joint compound at the edges.
Second Coat Tapered-Edge Seams
Second coat is much like the first coat except we will be applying more mud and widening the seams by about two inches.
First Coat Butted Seams
Butted seams are where two non tapered ends of panels are joined together. These joints are weaker and need the extra strength of paper tape to help reduce the risk of cracking. I also use a setting type joint compound for the first coat on butted seams but you can use an all- purpose joint compound. To first coat the butted seams is a bit different from the first coat on tapered edges between panels. The paper tape is not self-adhesive so you will need to apply a layer of joint compound to the butted edge first. To do this use a 6" mud knife to apply a thin layer of joint compound along the center of the seam, then center the paper tape over the center of the seam and lightly press the tape into place, keeping the tape pulled tightly to avoid wrinkles and straight. Cut the tape to the desired length with a utility knife or the edge of the mud knife. Now starting at the center of the seam, using even pressure with the knife held almost flat against the panel, pull the knife along the seam toward each end, smoothing the compound with the back edge leaving a layer of compound that just covers the tape. Be sure that the tape is straight and free of wrinkles. Clean any excess joint compound from along the edges making sure that the first coat is no more than 6" wide.
First Coat In-side Corners
Inside corners can be a bit tricky to keep one side of the corner smooth without roughing up the other side. The best way I have found to mud inside corners is to again use the setting type joint compound, paper tape and a 6" mud knife to apply a layer of joint compound to both sides, making sure that the entire corner is covered with joint compound. Fold the paper tape along the crease and lightly press it into the corner keeping the tape straight and wrinkle free. Now using a 6" mud knife with light pressure embed the tape into the corner working one side at a time. It may take a couple of times with increasing pressure to force the extra joint compound out, now feather the edges. (Hint) to help prevent excess joint compound from building up in the corner I usually turn the mud knife outward as I pull the knife along the corner.