Posted: 1/9/2013 12:07:32 PM EDT
|
Howdy,
I am currently balls deep in a remodel and am hanging up new drywall. I already taped and ran my layer of mud now I am sanding. My question is how do you know when to stop sanding? I know you want to blend in the tape as much as possible but how do you tell when it is good or when you need more? |
|
as a amateur drywaller myself I'd say you are experiencing the biggest problem with drywalling. Plenty of light at the right angle is what I use to make sure there's no ridge, ie the mud is feathered out properly. If it wasn't applied with a perfect or good feathering out, you ca still sand in a good feathering, it just takes effort. I like the sanding sponges myself. brushing off the wall can remove dust that filled or covered up ridges which made it look better than it really was. also, it's very easy to sand too far and expose the tape or corner bead or something. definitely prime it before painting. I just use the PVA type(lowe's gallon can say Contractors PVA Primer or something simliar) which is real cheap, $8/gal or so I think. I run the drop light around on the wall having it shine sideways across and seeing how things look, both before and after priming. If you see ridges and air bubble holes, sanding marks etc... well, you can apply more mud and sand more and prime again etc. If you see nothing but smooth even texture/finish with the light shining sideways across, all over the wall, then it should look fine with finish paint. I'm definitely not a pro, but have done quite a bit and have learned to get things acceptable with less coats of mud and sanding than when I started out. ETA: you can feather in a big glob of mud on the wall so that you see no ridge or seam, but it's still a big gob of mud sticking out. As you tape and top coat joints, you're making the joint wider (should be) so that you don't notice a hump. An 1/8" hump is less noticeable across 6 inches than in 1 inch, regardless of how perfectly feathered in they are. |
|
then you should never see tape.
Get a 12 inch knife, put an excess of compound in the joint. take the knife and straddle the seam, and run it the whole length. Put as little pressure as possible. Keep doing this till your knife goes all the way from one edge to the other and picks up little to no compound. Let it dry for a few days and then repeat, don't really "sand" it in between, just make sure you dont have any ridges that you are going to hit while trying to apply the next coat. After that dries good sand it ever so lightly until it is smooth. |
Shine a bright flashlight down the wall to see areas that need attention. Be careful with this though as you MUST, at some point, declare "enough" and quit. You can chase imperfections forever. Literally forever. 
For sure, NEVER sand the drywall paper. You must only sand the mud. Use the tips above and you will be fine--with practice. There is no magic--only proper technique and practice. 
|
|
Quoted:
Use a wider knife. And less mud per joint. It takes practice. this..... and this......... cant be said enough takes practice lots of practice you can read all about it, watch all the videos, dream about it in your sleep but it really takes screwing up a few times and over sanding a bunch of time before you find your style 
here is a special note, from the not so wise. its best to seal off a room while doing drywall I thought I was a real badass doing the drywall in my bathroom. door was closed fan blowing out the window. did you know the gap under a door is enough for drywall "dust" to escape and coat your entire living room? sat on the couch and "poof" instant   
|
|
Quoted:
Quoted:
Thanks guys. Ill go pick up a wider knife as my current one is about 5" I'd strongly recommend the good stainless steel one--don't get the shitty plastic ones. That too makes a huge difference. and again.... needs to be quoted buy better quality unlike what your thinking at the time of purchase you WILL be using it more than "just this once" better yet the plastic has a habit of not always staying flat when needed 
|
|
Quoted:
Quoted:
Thanks guys. Ill go pick up a wider knife as my current one is about 5" oh yeah, jeez, i generally start with a 6" to tape... sometimes i prefer to i start with a 4" to put tape on inside corners since you just do one side at a time. It was the biggest one I had
|
|
Quoted:
The first thing I usually do is to take a big drill and a paddle stirrer and mix the compound well. I also add water till I get the consistency I want. Don't be 'that guy' and mix liquid dish detergent into the compound in order to improve its 'slip.' The soap will break down the latex in the ready mix and greatly raise the potential for bond failure. Trade secret: ready mix is nothing more than elmer's glue and powdered limestone with a few other things tossed in to keep mold from growing inside the container. |
|
You really only need 6 inch knife and practice.
Easysand with minimal water to mix has far less shrinkage on hardening then pre-mix mud. You cam also control the workability a lot better than the pre-mix stuff. The only advantage pre-mix has is that it can be 'wet sanded' with a damp sponge. Keep in mind that plaster walls never saw sanding. The are troweled smooth. Skimming is far easier with a trowel then a knife. |