Walls and Ceilings - argh! inside corners

Hey guys. I'm pretty good at outside corners, but the inside corners drive me nuts. What I do is use my 6" knife to put 1/8" - 1/4" to mud all the way along both surfaces, then I wet my tape with a spray bottle of water, push it into place with my fingers, then I use my corner trowel to push it into place and hopefully push out some of the mud. Trouble is, it never goes easy. I have to push quite hard to get the trowel to seat into the corner and that seems to push out too much mud. Am I doing inside corners correctly? How runny should I Have my mud? Like milk? I have it quite a bit thicker than that.... thanks for any advice!

Milk like consistency would be way to thin. I think about frosting thickness would be close. I've never wet the paper. I like to use an offset 3" knife for taping but a 6" will work. 1/8" of mud should be plenty. Be sure to fold the tape first, then press it into the corner and run the knife over both sides.
The corner trowel should be used for the 2nd & 3rd coat - not for taping.

thanks for the feedback. Can you give an example of a 3" offset knife? Sounds interesting. I'm sure this will help over using the corner trowel!

I do as marksr said, although I don't use corner trowel much anymore. After the tape dries, I coat one side of the angle (5 inch knife, but 6 will work too) when I do the first coat over the flats, and coat the other side of the angle (corner) when I do the second coat on the flats.

I do fold the tape first too.

The angle trowel also works well, but I think it takes a little more effort to use one properly. (my .02)

The 5" offset knife looks similar to a "half moon". They are valuable when doing the top angle of a vaulted ceiling. If you hold the knife in front of you with the handle pointing down, the edge will be at a 45-ish degree angle instead of being horizontal

I hope this helps.

Heres how I do corners.

1. apply mud about 1/8- 1/4 thick with a 4 inch knife
2. fold tape
3. press into corner.
4. wipe down corner with 4 inch knife removing as much mud as possible. (no I don't get blisters or bubbles) You only need enough to hold the tape to the drywall and that doesn't take alot.
5.Next day coat one side with 4 inch knife , the other side the day after. Use a six to point up or apply a second coat if necessary.

Corners do not require alot of mud.

New finishing knives are a pain, the corners are too sharp and have a tendency to cut the tape in the corner (it takes awhile for a knife to get broken in,which is why I really don't like it when some laborer grabs one to scrape a floor).


No need to wet down tape before hand. IMO it would probably increase the chances of the tape tearing or accidentally cutting in the fold.

No need to add water to ready mixed mud. If I'm doing a small job with only a bucket or two of mud I usually don't.

Keep your pan and knives clean, I scrape mine down quite frequently to keep the dried mud off of them.

thanks for all the replies. I like the idea of doing one side of the angle at a time. I have tried using a 6" knife to do the corners (both angles at the same time) but just as I get one side looking good when I do the next side my knife always "dips in" to the other still wet angle, causing me to have to work that one more.

No need to add water to ready mixed mud. If I'm doing a small job with only a bucket or two of mud I usually don't. .



Although mud doesn't have to be thinned it usually works better with a little thinning. Even if you don't thin it is important to mix the joint compound well. Either mix with a drill and paddle in the bucket or for small repairs use your knife to mix it in the mud pan.

I'm a novice drywaller at best. I do one side of a corner and then wait for it to dry to do the other side - this actually takes less time for me than trying to do both at the same time and then trying to fix my mistakes.

My preference is to mud the inside corner using slightly thinned all purpose compound. I add no more than 8-10 ounces of water and mix with paddle and drill upon opening he pail.

once i have applied mud to inside corner, I lightly place the top three feet of folded tape into top of corner with finger tips . Now, I grab the inside corner trowel and angling the top or tip of corner trowel in (handle tipped away) i began drawing the knife lightly (top to bottom) into the corner floating the tape into the mud. if another stroke becomes necessary with the inside corner trowel I might increase the pressure slightly. Now i embed he rest of the tape using above method.

occasionally, a small section of tape fails to make contact with inside corner compound at outside edge. Don't worry about that because quickly I place a small portion of mud on tip of my 6"taping knife and place it well into corner holding knife inline with corner, and float compound out stroking knife perpendicular to corner line. Another quick float with the inside corner knife and then finish by floating the edges with the 6"knife which feathers edges/

Two coats and I have a nice inside corner joint.

bs5