When mudding drywall seams there are some things you should know. This coat is responsible for sealing the seam to prevent cracking. It can also cause you problems on the next coats if not done correctly.
There is more to this then throwing mud on the wall. The coat needs to be spread evenly over the seam. No holes or lumps should be left. The goal here is to cover the seam so the tape will be completely covered with mud on the back side. Any air pockets that are left will create blisters on the nest coat or when painting.
There are two types of tape to use, paper or fiberglass mesh. They have differences in use and installation. Here I am going to talk about paper because I feel that is best for the beginner.
Take the tape and cover the seam by running it longways and centering it over the seam. Make sure it has mud behind it everywhere, and cut to length. Wiping the mud off depends on the seam you are working.
Flats are the seams that run the length of the sheet rock. There is a bevel on the sheet rock for this seam. They are wiped over the whole tape making sure the bevel stays filled. Start about three feet from the wall and wipe towards the corner. The go back to where you started and wipe towards the other corner.
Cross Flats are the seam at the butt end of the sheet rock. Make sure there is no paper sticking out before putting the mud on. Run the paper tape out and cut to length. Wipe the tape one side at a time with the corner of the knife ¾ of the way over the tape. Do the same on the other side. Hanging the sheet rock vertically (stand ups) will eliminate this joint.
Angles are also a seam that need to be taped. Apply mud to both sides of the angle making sure to cover completely. Take the paper tape and fold it down the middle using the fold crease in the tape. Set the tape squarely into the corner using your knife. wipe one side and then the other to get it square.
Mudding drywall is hard but in no way impossible to learn. It takes a little know how and plenty of practice. Take a little time and learn about how it is done before attempting it. This will save you work in the long run.
The tools for this are pretty simple, you will need a six inch knife. This knife will be used for all your mudding drywall needs so get a good one. A four inch knife is good to have for places where the six will not fit. A hawk or mud pan to work from. I recommend the hawk because I find it easier to use and keep clean while working.
There are taping tools that put the mud and tape on at the same time, these are for larger jobs and contractors.
- Always wipe clean all mud and lumps before they harden, this will make the next coat easier. It will also reduce the amount of sanding you will have to do.
- Learn to bend the knife while wiping, this will improve your feathering technique and reduce edges.
- Use the correct tools for the job.
- Make sure the tape is completely filled behind it to prevent blisters.