One of the nicest things about finishing drywall is that anyone can do it. With a little practice and a little patience, even a novice drywall builder can have seamlessly smooth walls that only ask for a coat of paint to perfect.
There are of course some basic rules. The first is that you don’t start finishing until you have finished installing. That said, all of the drywall must be in place, each piece must be snug against its neighbors, with no cracks or gaps, and all outside corners must be neatly beaded.
The cleaner the surface and the cleaner the work area, the easier it is to get surfaces that are smooth, non-gritty, and lump-free. Think of it this way: anything that isn’t absolutely flat needs to be sanded until it is. And the second rule for drywall finishing is: minimize sanding wherever possible.
Even seasoned rehabbers are always amazed at the amount of dust and dirt that the simplest job can cause. It is not possible to get rid of it completely, but careful observation of the process at all stages can make the dust problem manageable.
Joints in drywall are covered by applying a thin layer of grout – old-timers call it “mud” – then embedding a strip of paper joint tape, and then covering the tape with a second and third layer of compound.
Try to develop a rhythm to work as smoothly and evenly as possible. It takes a little practice – start in a closet and polish your technique where it doesn’t show as much before starting on a room’s walls. The more successfully you keep the joint thin and smooth, the less sanding you will have to do.
While you are working, it is important to keep the joint and your tools clean. At the end of the day, clean all tools and towel dry them. If there are lumps on the site, take them out and throw them away. Have a spare piece of plywood handy to scrape off dirty joints.
The compound itself comes pre-mixed or dry (to mix itself) in 1-gallon or 5-gallon pails. The 5 gallon buckets have handles and, once empty, are reusable for so many things – from carrying tools to using them as a scrubbing bin or even a step stool – that they’re worth the price of connection. The premixed mixture is the best choice for beginners in drywall. However, you need to be extra careful to make sure the rest doesn’t dry out between uses.
The wide, flat trowels used to finish drywall work are called knives. A good selection of knives will go a long way in getting the mixture smooth – you’ll need 4, 6, 10, and 12 inch widths.
Other useful tools include a spool to hold the roll of drywall tape on your belt and a pan to hold a couple of knives.
full of connection. (Take out whatever you need and put the lid back on the bucket. This will keep the joint clean.) Start the process by taping the horizontal joints. Usually these are the joints where two beveled edges meet so that the tape is countersunk. Use a 4 “or 6” tape knife to apply a thin layer of compound – you want just enough for the tape to stick.
Measure out the tape you will need to make a single connection in one piece. (Hint: hold the tape against the wall with the knife and tear it against the blade. It will tear smoothly.) Use your fingers to place the tape over the joint and press it into the grout. Then go the entire length of the joint with the knife, starting in the middle and pulling the knife out at each end. Hold the knife edge flat against the wall and apply even pressure. The goal is to drive off practically all of the grout with the tape lying tightly against the surface with no air bubbles. You may have to think about it a few times first. Then scrape off the excess grout and scrape it back into the pan.
Tip: To embed the tape, hold the knife with the blade flat against the wall and your hand close to the surface of the wall so that there is a narrow angle between the knife and the wall. To remove excess mass, keep the blade flat but increase the angle by placing your hand a few inches away from the wall.
Once the horizontal joints are done, make the vertical joints. Then do the corners. You can do both sides of an outside corner at the same time. However, unless you are an expert, you should only do one side of the inside corners. Because of the corner beads, outside corners need a lot of grout to fill. Start with a 6 inch knife and apply as much compound as needed to keep it flush.
Let the grout dry. If you’ve been working fairly slowly, some of the first joints may be dry by the time you finish the last one. but the outside corners will likely dry overnight.
Now it’s time for the second coat, the block coat. If you’ve carefully installed the drywall, most of your joints should be beveled on both sides. The point of block coating is to fill in the bevel from edge to edge. Use a 10-inch knife to cover the tape with a thin layer of compound. Keep the pressure even and the blade flat. Work on the angle to get the most even coverage possible. Remember to use a narrow angle to apply, a wider angle to scrape off.
Scrape the grout as smooth and level as possible. It helps to work in long strokes and keep moving; Every time you pick up the knife the edge will leave a comb in the ## joint.
At the corner, use the 10-inch knife to apply the second layer to the outside corners. Use a 6 inch knife for the inside corners (you only fill half the bevel).
Once the second coat is complete and dry, you can apply the third and final coat. If you’ve been careful, worked cleanly, and removed all debris, you shouldn’t have to sand by now. Occasionally, there may be a small composite comb between the coats, or a glop accidentally landed somewhere in the seam or on the wall. Use a knife to scrape away the burrs and slough off the bumps. If the surface is still not smooth, you may need to do some sanding at this point.
Use a 12 “knife for the last layer of the joint, except for the inside corners where you will use a 10” knife. The third layer of the compound should cover the bevel and extend a few inches on either side to the feathery edges. Again, use long strokes to minimize burrs.
When the last coat of paint is dry, it’s time to sand. Seal off the area in which you are working with sealed plastic sheeting. You may want to leave a window open while a fan blows out. that can help drive the dust away. Wear a dust mask.
Use 120 grit sandpaper and invest in a sanding bar – a long bar with a plate on the end that swivels in all directions. You can buy pre-cut paper that will fit on the plate. Grind only when necessary. It is helpful to have a bright light that can be trained on the surface you are working on to illuminate ridges or bumps. In tight spaces, you may need to sand by hand. (You may want to wear gloves. The dust gets embedded in your skin and can really dry it out.)
Not over-sanded. They can damage the surface of the paper or the tape. If an imperfection can’t be easily sanded, you’ll need to go back later and touch up that spot with more compound.
Once the walls are dry and smoothed to your satisfaction, you will need to clean them before applying paint. A clean dust mop is a good tool. try to shake it out the window. Then vacuum the floor; It may take a few passes for the dust to collect. Once you’ve got the dust off the walls and out of the room, it’s time to apply a smooth, professional-looking paint job.
Mr. Johnson is a construction manager in Baltimore. Ms. Menzie is a feature writer for The Sun.
If you have any questions, tips or experiences about working on houses, write to us at c / o HOME WORK, The Sun, 501 N.
Calvert St. Baltimore, 21278. Questions of general interest are answered in the column. Comments, tips and experiences are published in columns from time to time.
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