Tim gave a pretty good account of what mudding is going to take to do, but, it isn't quite as bad as he makes it out to be, even though I thoroughly hate doing it myself...
This should give you a pretty good mud job.
Use regular tape in corners. Use the webbing type of tape on wall seems. The reason I say use the webbing stuff on wall seems is that it is much easier to get to lay down smooth. In the corners, it doesn't work at all.
Wall seams:
Don't bother with the heavy duty type of joint compond. Use the light compond. It actually doesn't hurt to water it down just a tiny bit. It is easier to work with then, and you have a bit more working time before drying and you being a beginner, this will be important!
Apply the webbing tape to the seam. Then, with a 6" flat blade, apply a thick enough coat to cover at least 95% of that tape. Make sure that you don't have really heavy built up edges. Smooth those down in a way that does not create craters in the mud. A little build up isn't too hard to knock down, but craters are annoying.
Wait to dry. Go back with your blade and scrap off what little build up's on the edges you can knock off easily. At this point, that is all you have to do.
You next coat will be applied with a 8" or 10" blade. I prefer 10", but 8" will work okay too. 10" is a little harder to work with, but helps "fan out" the mud a little better. Maybe you should stick with the 8" blade.
Apply the mud again. This time, you really need to make sure that you have full coverage over the tape on the seam. You want a pretty consistent thickness across the whole width of the blade, and you really want NO craters in the mud. This will take some practice to do right. If you have some tiny craters, don't sweat them too much as long as the consistency of the rest of the mud is good and you don't have ugly edges.
Let dry. At this point, what you do depends on how well you did the last coat. If your edges don't have a huge build up, again, you can pretty much just take your blade and knock off the build up on the edges. If it is built up pretty high, it might be time for a bit of sanding. If you have to sand (and I feel sorry for you if you do) make sure you wear some kind of protective suit over your clothing and a FACE MASK!!! Also, don't waste your time on trying to make a sanding screen last a long time. When it quite knocking off a lot of mud, REPLACE IT!!! Let the sanding screen do the work FOR YOU!!! Sand the edges so that they are fairly close to being smoothed out to the drywall. You will need to sweep down the seam afterwards to get rid of dust. Clean up your floor and proceed.
Next coat, use a 12" blade. At this point, you are mostly concerned with filling in any craters and smoothing out the edges as much as possible. With a little practice (you should have plenty of practice by now!
) you will have your blade angles down to get a nice smooth run of mud.
Let dry. If your build up is still kind of high on the edges, sand a LITTLE again. But, only a little.
Get a 5 gallon bucket and fill it with water and get one of those really big heavy duty sponges. Dip the sponge and only wring out enough water to keep it from dripping all over the place. Wipe down and fan out your edges with the sponge. It won't take you too long to know how far you need to do this. Wet sponging is the one thing that will give you very good results and is far less messy than sanding. You will be wringing out your sponge a lot and replacing the water a lot with fresh water, but it isnt that big of a deal.
Vola! You should have your edges of your mud blended out about 6" either side of the seam, and it should look very "feathery" and smooth. If you need to do a little touch up mudding, at this point, spackle will be much easier to work with and will dry faster. Touch up as needed.
If you are going to texture the walls, you don't need to be quite as anal about smoothing out the edges as much as if you would be if the walls will have no texture (I love a textured wall!
less work!)
Corners:
Pretty much the same type of deal as doing other seams, BUT, you have to use regular drywall tape, which means that you have to apply a little bit of mud BEFORE you put the tape on, and then you have to put mud over the tape. When applying the tape to the mud, you HAVE to make sure that you get the tape down as smooth as possible. The webbing type of tape is easy to do this with because of the "holes" in it, but regular tape doesn't have "holes". If you can't get it to lay flat at some place, poke a little hole at the center of the "hump" so that the mud below can seep out. Remember, the tape need to be as flat as possible, but you also have to make sure that it get's 100% buried in mud too.
Corners are hard, and pretty much, you will be doing more sanding on them then you do on seams. Just do the best you can with applying the mud as smooth as possible. Use a 6", and 8" blade. You will probably elect to sand between all coat. Wet sponging at the end will make it all blend out really well. Remember, if you are going to texture, you don't have to be as anal. You just don't want a big "lip" between the mud and the drywall if you are going to texture. If you don't texture, then you need to have it feathered out very smooth. The hardest part about corners is that if you try to do both "sides" of the corner at the same time, you will probably put craters in the mud of a side you just did trying to do the other side. Those corner blades are okay at avoiding this, but they are very tricky to use. So, if you have the time, you might consider doing one side of the corners one day, then the other side the next day after the first side dries. Yes, it will take twice as long per coat, but it will be easier to do in the end.
Anyway, mudding sucks even when you know what you are doing. Take your time and don't give up. Sanding sucks, but it can fix just about anything "bad" that you do while applying the mud, so most important, just get the tape 100% covered, and make sure you have mud on the drywall far enough away from the seems and corners so that you can feather the mud out.
Good luck. LOL
Ed
