Taping drywall like a pro using USG All-Purpose Joint Compound (green box) involves several steps to ensure a smooth, professional finish. Here's how you can do it:
Materials Needed:
USG All-Purpose Joint Compound (Ready-Mixed)
Drywall tape (paper is preferred for strength, Fiba-fuse is also a great choice)
Drywall knives (6-inch for taping, 10-inch for 1st and 2nd coat, and 12-inch for mud application and smoothing)
Sandpaper or a sanding sponge (medium and fine grit)
Mud pan or hawk
Corner bead (for outside corners)
Utility knife
Step-by-Step Process:
Preparation:
Ensure the drywall is properly installed. All panels should be secure with no gaps larger than 1/8 inch. If there are gaps, use shims or additional drywall pieces to fill them before taping.
Apply Tape:
Inside Corners: Fold the tape in half lengthwise and crease it. Apply a thin layer of joint compound into the corner, press the folded tape into the compound, and then apply another thin layer over the tape. Smooth with a 6-inch knife.
Flat Seams: Apply a thin layer of compound to the seam, lay the tape into the compound, then press down with the knife to embed the tape. Apply another thin coat over the tape, ensuring no bubbles or wrinkles.
First Coat:
Use a 10-inch knife to apply a layer of compound over the tape. The goal is to cover the tape completely but not to build up too much mud. Feather the edges outward to blend with the wall. Let this dry (typically 24 hours depending on humidity and thickness).
Second Coat:
Once dry, apply a second, slightly wider coat using a 10-inch knife. This coat should extend beyond the first coat on each side to start blending the seam into the surrounding area. Again, feather the edges. Allow to dry.
Third Coat (and Fourth if necessary, no shame in a 4th coat if needed)
Use a 12-inch knife for the third coat. This should cover the previous coats, with edges feathered out even further. The idea is to make the repair invisible. If the seam is still visible or if the mud application wasn't smooth, you might need a fourth coat, especially for perfection.
Sanding:
Once the final coat is dry, sand lightly with medium grit sandpaper or a sanding sponge, then finish with fine grit to remove any bumps or tool marks. Always sand in a well-ventilated area or use a dust mask.
Corners and Finishing:
For outside corners, install corner bead before you start taping, then apply compound over it similarly to flat seams, taking care to keep it straight.
Check your work under different lighting to ensure no shadows or bumps are visible which might show imperfections. We prefer a halogen or L.E.D light.
Cleanup:
Clean up any dust, and if you've sanded too much or created any imperfections, apply a skim coat if necessary.
Tips for a Pro Finish:
Consistency: Keep the mud consistency right (sour cream consistency); not too wet or too dry. If it's pre-mixed, it might itbwill need a couple splashes of water to loosen the company.
Application: Apply mud in thin layers; thick layers take longer to dry and are harder to sand.
Patience: Each layer needs to dry completely before you add another or sand. Rushing can lead to cracking or peeling.
By following these steps and taking your time, you should achieve a professional-quality drywall finish using USG All-Purpose Joint Compound. Remember, the key is in the details and patience.