How to Finish Drywall

Finishing drywall well is a learned skill. The professionals do it quickly and well because they do it for a living and have learned tips to avoid the common problems that bedevil beginners. If you're doing drywall finishing for the first time, you won't match a professional for speed and efficiency. But if you follow these tips, and are patient, you will end up with a drywall finishing job any professional would be proud to call his own.Joint CompoundJoint compound (or mud) is available in three basic styles:All purpose (or general) joint compound: The standard joint compound used to some extent on any drywall finishing project. Available pre-mixed or powdered. Tip: Buy the pre-mixed. It doesn't cost that much extra and saves much time and aggravation.Light-weight joint compound: Preferred by the professionals for the final coat because it is smoother and easier to finish than the all-purpose compound. Tip: If you are a novice, use this type sparingly. It's lighter because it has more air, which can result in pockmarks on the finished surface if it's overworked - a common problem with beginners. Stick with the all-purpose compound unless you just can't get it smooth.Setting compound: Used for those rough jobs where wide holes or gaps must be filled, or for applying over fiberglass mesh tape. This compound is available only in powdered form and sets up quickly, leaving little time for working. It isn't normally used as a finished coat, only as a base coat to get a rough surface up to the point where it can be finished.Drywall TapeThere are only two remote controlled air swimmers kinds of tape:*Paper tape: According to professionals, the only style to use. It's the strongest and easiest to cut, but a problem for first-time finishers because it can trap air bubbles underneath it if it isn't applied with enough joint compound.*Fiberglass mesh tape: Weaker than paper tape, and can't be cut easily with a taping knife. Easier for novices because it is sticky on one side and won't trap air bubbles. It is recommended that the first coat of joint compound with fiberglass tape be the setting type, but for residential uses, this is typically not necessary. Tip: Do not use mesh tape on inside corners. It won't hold up. Use only paper tape in those situations.The ToolsOnly a few basic tools are necessary for finishing drywall. But don't scrimp on these. Buy high quality tools and they'll repay you with high quality work.4" drywall knife: Also variously known as a putty knife or taping knife. Some professionals use only this tool for finishing drywall, relying on skill to get the wider joints smooth. This is a little risky for the beginner, so also purchase at least the 10" knife.10" drywall knife: Used for the second coat of joint compound.14" drywall knife: Used for the third and final coat of joint compound. This knife is optional, since the 10" knife can give you satisfactory results. Still, if you're a purist and want to do things right, buy this blade.Mud pan: Flat, square plate with a handle for holding small quantities of drywall mud. Optional for small jobs; but handy to avoid lugging around a one or five gallon bucket of mud.Sanding block: Buy an inexpensive sanding block with a supply of pre-cut 100 grit sandpaper or drywall screeds to fit it. If you're going to be doing a lot S107 RC helicopter of ceiling work, you may want to invest in a professional extension rod with pivoting, swivel-type sanding block on the end. They're nice, but optional.Drywall hammer: A special hammer with a nailing surface. Useful for tapping those drywall nail heads that weren't set quite deep enough. Your regular hammer will do, of course, but the advantage of the drywall hammer is that it is much less likely to break the paper surface of the drywall - a problem for finishing.Goggles or eye protection: For sanding.Dust Mask: For sandingThe FinishingFinishing Joints: Use the 4" knife to spread joint compound into the cavity created where the tapered ends of panels abut one another. Work the compound into the joint, and fill the tapered recess until it is flush with the face of the gypsum board. Cut a piece of paper tape and center it over the joint between the two boards. Use the 4" knife to embed the tape in the mud. Spread a layer of joint compound over the tape, working downward with the knife at about a 45 degree angle. Clean the blade, and go over the joint a second time to clear off any excess. Work to get the joint as smooth as you can, but avoid running the blade over the paper numerous times. It can raise the nap on the paper of cut through the face of it.At butt joints - where the non-tapered ends of two pieces abut (to be avoided, by the way) follow the same procedure, except place enough joint compound over the joint to leave the surface a little high. This hump is to allow you to feather out the face of the wall and avoid a ridge where the butt ends of the panels meet each other.Outside Corners: You should have already installed a corner bead, a metaledge that fits over the corner to allow you to finish the corner Remote Control Air Swimmer cleanly and easily. Note: Install corner beads with the sides angle in slightly to allow better finishing. Make sure the nail heads are inset slightly. Use the 4" knife to apply joint compound until each corner is filled even with the corner bead. Simply run the knife along the metal edge of the corner bead until you see that the 4" width of joint compound is full and even.Inside Corners: There is actually a special L-shaped finishing tool made for inside corners - called a corner knife. Buy it if you feel the need, but you can finish inside corners perfectly well with a standard 4" knife. Begin by spreading a 3" width of joint compound on each side of the wall, carrying it into the corner. Cut the paper tape to the proper length. You'll notice the tape has a small crease in the middle, making it easy to fold it lengthwise into an "L." Push the folded tape back into the corner, slightly recessing the crease into the joint compound. Use the 4" knife to embed the tape into each side of the corner. Clean the knife and run it along each side again, removing the excess mud.Nail Dimples and other holes: Use the 4" blade to fill each hole with joint compound. If they're a little on the deep side, it may take two or more tries to result in a completely flush surface.Second Coat: Give the mud at least 24 hours to dry before checking it. If you have very humid conditions, or it is cold, allow longer. Whatever you do, make sure the joint compound has dried thoroughly before applying the second coat. The purpose of the second coat is to increase the width of the joint (called feathering). Before doing so, check all of the previous day's work for ridges or rough areas. Some ridges, particularly the high ones, can be scraped down with the 4" knife (just be sure not to damage the paper tape in the process). Others can be lightly sanded. To apply the second coat over the joints and inside corners, use the 10" wide knife to spread a smooth layer of joint compound. If you don't have a mud pan for holding the joint compound, use the 4" knife to "load up" the 10" blade with mud. Remember, with the second coat we aren't using as much mud. The goal is to spread the finished width, smoothly and evenly.Third (Final) Coat: If you've done your job well, the third coat will be the last. After waiting another day for the joint compound to dry completely, use the 14" knife (or 10" knife) to spread another layer of mud across the width of the joint, widening it by about 4" total. If you're using a 10" knife for this task, take care to keep one edge over the approximate center of the joint to ensure you are staying relatively flat across the entire width of the finished area. Oftentimes, you will find that the inside corners do not need a third coat.Final Sanding: Wait another 24 hours, and inspect the joints closely. A halogen lamp is great for raking light across the wall to illuminate even the smallest imperfections. Check small nail holes closely to see if any depressions remain. Look for ridges, scrapes from the edge of the knife, or pockmarks in the finished joints. Use the sanding block with 100 grit sandpaper or a drywall screed to lightly sand away imperfections. Take it easy with the sanding. Avoid sanding through either the face of the paper tape or the drywall. In general, the best finishing jobs require little sanding. Remember to wear a dust mask while sanding (and eye protection is a good idea as well). We don't want you getting white lung!If the wall stands up to your close inspection with a halogen lamp, it'll survive any amount of scrutiny from your mother-in-law or crazy brother. So clean up, paint or paper the wall, and enjoy your handiwork.