Walls and Ceilings - Mudding drywall...

Hi all. I am mudding the drywall I just hung in the laundry room at my house. It's the first time I ever done it, so it's not going all that well. Not all that bad either I guess. My question is, if I leave the coats, including the final coat a little choppy, thats nothing I can't make up for by carefully sanding right? As long as I smooth each coat out by lightly sanding between the coats and sand the final coat very well til its perfectly uniform and smooth ill be ok right?

Sanding joint compound can get old real fast. Better to get it as smooth as possible when you are putting it on.

I suggest putting on the first coat and just sand off the high spots when it dries. Don't worry about sanding grooves and low spots smooth. Fill them in with the next coat. Use the knife blade to knock off the small ridges. It's faster and easier than sanding.
The second coat is the same process except make it wider and smoother. Try to fill in all the grooves and divots. Again sand off the high spots and put a final (thin) wide coat to feather in the edges and fill any remaining blemishes. If you do it right you shouldn't have too much sanding to do when it dries.

A thing to remember is that if you can see a defect before you paint, it will be twice as visible with paint on it and 10 times harder to fix.

I agree 100%, the less sanding the better!!! I would rather apply an extra coat of mud than do extra sanding.

I would also add make sure the 1st coat is dry before you apply 2nd coat of mud or you run the risk of the weight of the mud pulling the tape loose. I made this mistake my first time out :eek: :wall:

What Wayne said is exactly right. ESPECIALLY the part about using the blade to knockoff any high spots - that's a tip I do not see mentioned nearly often enough, its a big help. You will want to avoid sanding at all costs as mentioned especially considering the dust is pure evil. Now, from your post is sounds as if you have already left some ripples and such and are asking if you can get out of it? The answer is yes. It won't be fun or easy but you can correct lack of smooth finish by sanding, it just takes a while. Use a fine grit screen or paper to do the sanding and be very gentle. Grab yourself a drop light and hold it up close to the wall as you sand, this will help you spot real trouble areas. After you sand one coat and are on to the next, try hard to follow Wayne's instructions. You'll be much happier sanding just to smooth out than you will sanding to get uniformity. Good luck.

Use a fine grit screen or paper to do the sanding and be very gentle.


Be sure to use a pole sander or even a hand sander - something that holds the sandpaper/screen flat. Sanding by holding sandpaper in your hand with no stiff flat backing will cause even more dips.

more questions then...

* what is the difference between plaster and drywall compound?

* what is skim coating and when do I do it?

* If only use compound over the nail heads and seams, won't there be a wave in the wall where the bare drywall has no compound on it?

Nail heads (does anyone still use nails?) are done with the knife almost perpendicular to the wallboard. Use just a little compound. Other than what's in the nail hole, there should be little compound on the paper. The mud will shrink a bit, you may have to go over a couple of times.

Skim coating is using a broad knife and minimal compound. You can skim coat to cover minor blemishes or to extend the width of a joint so that there is no visible buildup at the seams.

In order to get as many coats on in the shortest possible time and get them smoothed out, you may want to buy powdered drywall mix in a timed formula. I use the 45 minute stuff, and it allows sanding after about an hour or so, and the second coat can go right on. 45 minutes means 45 minutes, so you can stop and have lunch while you are coating.

* If only use compound over the nail heads and seams, won't there be a wave in the wall where the bare drywall has no compound on it?

First all nails [screws too] should be sunk slightly below the surface. The indentation that the hammer head makes is sufficent.

All your long seams should have a factory beveled edge which allows room for the mud and tape without build up. Butt joints [which should be staggered] require floating the mud out [more with each coat] until the finished joint is 18"-24" wide.

If you use hot mud [powdered quick dry] be sure to not mix up a large quanity - only what you can use before it starts setting up. Once it starts to set up throw any left over mix out and clean your pan, knife and bucket.

and with the powdered mix, be sure you are dilligent about wiping off the knife on the mud bucket. That stuff starts to setup in minutes on a knife left out in the air... It'll get a little stiffer and be harder to use. keep some water handy to continuously refresh the mix and keep it thin enough. Take care not to leave it too thick as well. If you are an absolute beginner, you may want to go get your feet wet w/ the premixed stuff. Its much less intimidating and much more time forgiving. If you need to get some up on the wall and stop and look at directions or something, you don't want to be using the powdered stuff...

Firstly. I still use nails. I also use glue on walls and ceilings. With glue your fasteners don't matter so much. In fact you could take them out after the glue dries and it would be stronger then with just screws. The occasional nail pop but there are hardly any as long as you don't miss the stud. Anyway that is off task. This is how I finish sheetrock. It's not my main area of expertise but I have done enough now to be fairly good at it even if I would rather do just about anything else. I do it in 3 layers. (the really good guys can do it perfect in 2 but not me) First the tape joint. With a 6" knife (get a good one like a marshaltown) I spread about a 1/8" thick layer of mud everywhere I need to tape one joint at a time. This is premixed mud right out of the bucket. leave the powdered kind alone. Place the tape lightly at first over the joint and when it is on the full length, scrape off all extra mud sticking the tape down tight. Let dry several hours. Now the second and most challenging layer. Sometimes known as "block" joints. I usually use a 10" knife for the joints and the 6" for the corners. The idea is to get a fairly thick covering over the tape so that it does not show and at the same time not having it thick on the edges so you have somewhat of a taper. The corners can be a bit tricky so I recommend doing one side at a time for beginners. It is much easier if one side is dry before you do the other. I also mix a little water in the mud for this stage. Makes it less stiff and easier to work with. Butt joints will need to be wider then the tapered factory seams to hide the hump. Again important not to have the edges too thick. You will end up sanding too much off to get it smooth. The last and the one that the real pros can skip is the skim coat. This is mainly to widen the joints a little and to smooth out bumps and the edges of the mud joint. It will also make sanding easier. This I think is the easiest since you want to scrape kinda hard and don't have to mold the mud like you do on the second stage. This all takes a little practice and some patience but it can be done. I hope any of this made any sense. Good luck!

I'm in the process of finishing out one of the rooms on my remodel. I am trying to figure out why the corners are cracking when the compound dries? Will it do that if there I use too much compound on each layer? How can I fix it without having to keep going over it?
BTW, I did use corner bead tape, it is reinforced with metal strips. Works great everywhere but inside corners it seems so far.

Hualinbass02

Sounds like you have applied the mud too thick, the next coat should take care of the cracks which are caused by drying. I prefer to thin the mud slightly which makes it pull easier and float out smoother = less sanding :cool:

I have never used the corner bead tape anywhere but on off angles [non 90`] I have always used corner bead on ext corners and fold the paper tape for inside corners.

Thanks Marksr, that's kind of what I figured. This should be the last coat anyway and I was planning on thinning it out for this one. On the next room I will try thinning it out a little when I put it up and see if that helps.

There are little tricks one can pick up over time, with anything one does, even when self-taught. When feather edge skim coating at the edges, to cut down on sanding (sometimes I do not sand at all!), you can lay down a run of joint compound off a broad knife by ...instead of pulling the broadknife down the joint as you normally would...you instead let it slide off the edge of the knife by running the knife 90 degrees to what you would think. i can skim down the edge of a joint with a feather coat in seconds this way. In other words...if you have an 8 foot wall corner mudded, but goofed a little and there is this ridge of mud that is out from the corner 4-6 inches where the mud meets the sheetrock...well, we all know you can sand off the ridge. But instead, you may want to simply run a feathercoat of mud over this slight raised mud, and by doing it the way I say, you can do it extremely fast. You can let like a 1-2 inch wide x 3foot swath of mud come off say a 10 inch broad knive this way, in one pass.

Haulin - I used the corner tape you are referring to and found it perfect for inside corners. I actually didn't use it on the outside corner because of a special situation. But just so you know, if you like it and found it easy to work with, you can also buy the same thing as a piece of corner bead. It will be in w. all the metal corner bead and its prebent and comes in 10 foot lenghts. You can cut it to fit and the reason you buy it like this instead of in the tape form for some applications is that it comes this way in different strengths and widths. Subsequent coats should fix your cracks. I found it best to thin the mud out a bit by simply dipping the knife in a bucket of water and mixing it in a bit. A very little water thins a long way.

The hard way is a great teacher that taught me to take my time. Be patient! When you start getting tired clean up and call it quits!

Andy

I've now done a few new walls and some patches, and I'm trying to get techniques down myself--it's frustrating! One thing I learned in here that helps me a lot and reduces or eliminates sanding is using a wet sponge. In between coats, get a large, fairly firm sponge (I used one that was sold for tile grouting), and a bucket of water. After knocking off the high ridges and bubbles with a 6" knife, wring most of the water out of the sponge and smooth out your joints with this, instead of sanding. Rinse the sponge and change the water out often. I have been able to avoid sanding all together on some areas. Others just required a light sanding.

One thing I learned in here that helps me a lot and reduces or eliminates sanding is using a wet sponge. In between coats, get a large, fairly firm sponge (I used one that was sold for tile grouting), and a bucket of water.
There is a sanding wet sponge sold specific for drywall work. It looks very similiar to the grout float. Should be found most anywhere drywall tools are sold.

Ok.. my husband and I are in the process of building a diving wall in our garage so our tenants have their own section. My question is, do we have to use tape or can we just use the joint compound to fill the holes and joints? Thanks in advance!

Sally

I would use self adhesive fiberglass mesh tape. Put it on the seams, then mud, if not you will find cracks on the seams sooner or later. Also you can put down a thin layer of mud, and wet paper tape and put it over the seam then mud that. Either way will work, but I wouldnt do it without drywall tape. The small holes, 1/4 to 3/8 I would just mud.

You defenitetly want to use tape on all the joints. Paper tape is better but the 'sticky' tape may be easier for you to use. Flat paint will help to hide [or atleast not accent] any irregularities you might have in the drywall finish.