Finishing drywall?

gone_fishing · 02-12-2009, 09:56 PM

Can some experts give me some advice on finishing drywall? I've done it but want to do this project well.

1) Mesh or tape?
2) What order do I do? Corners then seams?
3) How do I handle overlapping tape in corners?
4) How much soap do I mix into the mud?
5) Should I add water?
6) Other tips?

THanks!
Kevin

Bob Mariani · 02-12-2009, 10:29 PM

1) Mesh or tape? Paper tape is stronger ,mesh is easier for a beginner. If you use mesh use "hot mud" only for the first two coats. This comes in a bag and is mixed using water and an electric drill with a paddle bit. Drys much harder.

2) What order do I do? Corners then seams? Does not matter at all.

3) How do I handle overlapping tape in corners? No over lapping involved. Use paper tape in the corner, which folds down the middle. Hold your finger in the middle fold and slide it along the tape making a 90 degree crease. With second and third coats you will find it better to only do one side of the corner one day and the other side the next day to avoid the knife cutting into the opposite wall as you tape

4) How much soap do I mix into the mud? Very little very little water. Some but not many pros will do this. And it is also not a recommended method by manufacturers. Use the mixed mud and you will not need to even think about this. Some do it claiming it helps control bubbles in the mud finish

5) Should I add water? Very little if you feel the mud is not flowing well. I never use it, just mix the mud well and you will be fine. If it feels stiff, then add water

6) Other tips? Pre fill with the hot mud all bad and open joints. Layout drywall to limit square cut corners. Do not apply too much mud. First coat apply enough to embed the tape and a little over it for a skim coat. Second coat apply coat over the seam and beyond it. Use a flat trowel against the wall perpendicular to the seam to see if you have enough mud to fill the concave made by the recessed seems Keep in mind the mud will shrink. If you have a pile of dust after sanding, you sanded too much and placed too much down. Very little sanding is needed until the final coat. Third coat is applied over all seams and screws. Use a wider knife (10') Feather out both sides of all seams. Remove all excess mud by pulling knife almost perpendicular to the wall. you are only filling in minor scratchs and misses with this final coat. Hope that gets you thinking at least.

gone_fishing · 02-13-2009, 07:18 PM

Bob, good stuff. I have never used hot mud. Are you saying to fill the cracks before starting to tape?

bjbatlanta · 02-13-2009, 07:21 PM

Bob pretty much covered it. For any large job (20+sheets), paper tape is best and ready mix mud. Much easier. Add water sparingly until you get a consistency to the mud YOU are comfortable working with. I add soap, maybe a couple of tablespoons worth, to a 5 gal. bucket. Not necessary for a DIY'er especially if this is you haven't done much finishing. As Bob said, if you use mesh tape a setting type compound should be used for at least the first coat. (Second coat won't hurt.) Main thing to keep in mind is less mud is better. Several thin coats are better than trying to cover in one coat. (Won't work anyway.) The mud is "semi transparent" when it's wet (you can see the tape through it in places). The natural tendency is to build up the mud so you can't see the tape. Actually after the mud dries, even a "thin" coat, it's white (opaque) and the tape can't be seen. Even if you see some spots of tape after sanding due to irregularities in the wall, tape is a paintable surface. Take your time.
I think Bob meant pre-fill any large gaps 1/4" or larger. Use setting type compound.

Bob Mariani · 02-14-2009, 08:01 AM

I think Bob meant pre-fill any large gaps 1/4" or larger. Use setting type compound. __________________

Exactly what I mean. Wait for this to dry completely before covering with more compound and tape like you would with any other seam or screw hole. The other think to consider is to thoroughly inspect all drywall to be sure it is completely screwed down and tight against the studs. Any loose sheets will cause cracks latter. And run a knife along all the screws to assure that they are completely embedded in the drywall. Beginners should use the dimpler bit to be sure the screw is set correctly.

yummy mummy · 02-15-2009, 12:25 AM

I would recommend thining the mud down and applying thin coats.
I applied 4 coats with great results.

I also wet my knife before pulling it through. You can also wet your tape before putting it on.

Make sure you put enough mud on the seams or you will have the tape pucker in places where there was no mud underneath for it to adhere to.

I encountered that problem at times, and then I had to cut the bubble out and re-apply the mud in that area.

Good luck.

gone_fishing · 02-15-2009, 10:29 AM

Promised my wife I wouldn't do any work this weekend...that didn't last. Baby was sleeping and she was cleaning so I did the first coat on the screw holes. I also did a test run on taping in seems that will not be visible. I think I did okay but will let them dry and see how they look before continuing with more visible drywall.

Oh yeah, I used premixed that I thinned a touch and tape. Need to get hot mud for some of the gaps before taping much more.

Thanks again for the advice. I will certainly post pictures once done.

gone_fishing · 02-16-2009, 08:11 PM

Ok, finished with the taping today. I am getting slight crinkles in some of the tape. Guess it's from it bunching as I am setting it in the mud. I think they will be fine when I put the next few coats on. Otherwise I think it looks pretty good. Waiting until I get this room complete before doing the office.

Bob Mariani · 02-17-2009, 06:20 AM

you will need to cut out the wrinkles, not cover them with even more mud. Wrinkles means you had too much mud behind the tape. Also using premixed with the paper adds to your problems, although many will do it. Mixed dries faster and harder and is much better for the first coat. But maybe not best for beginners since sanding is much more difficult.

Eric Brown · 05-14-2009, 07:04 PM

Always use premixed joint compound if you are a diyr. Only use the bag mud for your first coat on the corner beads. And get 90 minute not 45 or 20, unless you need a new boat anchor.