The "bead" or outside edge needs to be installed proud of the notches. In some cases this will result of a corner less than 90`. If your bead is more than a 90, you are going to have a very difficult time trying to finish the corner out.

 

1 of two things are happening , 1 you pushed the bead on to tight, 2 you are using a knife that is to flexible. put a strait edge accross the bead and see if there is some daylight between the bead tabs and the straight edge.

 

thanks for the replies.

i forgot to mention that this is bull nose corner bead.

the notches are cut halfway into the bull nose so i dont understand how to fill it in with mud to make the radius solid like a normal corner bead.

 

I installed a 8 foot section of rounded bullnose metal cornerbead, and found it wasn't working... So I took it off, and cut an extra 1/2" of drywall on both sides, they could not be coming to a perfect 90º angle.
Then, re-installed the bullnose, and everything worked like a charm.
Very easy to mud afterwards... I just figured this out myself, wish they came with instructions... Is this helpful? I'm not sure if I understand your troubles exactly...

 

Can you post a picture of what you've got so far??

 

its the stuff they sell at Home Depot or Lowes, they have the regular corner bead and then they have the arch cornerbead which is what im talking about. it has cuts that go perpindicular to the radius every inch or so and they are at least 1/16'' wide.
So when i drag my knife across them it dips in the cuts of the bead.

ill try to post a pic.

 

its the stuff they sell at Home Depot or Lowes, they have the regular corner bead and then they have the arch cornerbead which is what im talking about. it has cuts that go perpindicular to the radius every inch or so and they are at least 1/16'' wide.
So when i drag my knife across them it dips in the cuts of the bead.

ill try to post a pic.

now I get it, I can imagine that being hard to mud up, even if you have to sand after, lots of work... The stuff I had did not have that, so did not require mud on the large radius part of the bullnose.
Is it made for bending at large radius?
can you buy regular stuff without those dips?

 

yes it is made for bending it on archways.

 

I have not come across this stuff yet, as I have only used straight stuff.
I would say, use straight stuff where you can. They should take back unused lengths of the ones you have. And, where you have to,
just dump mud on it, and let it dry one to two days, then sand by hand for a perfect finish. I don't imagine the radius should be muded too much, it should be feathered up to it, but not on the radius it's self.
Let it dry hard hard, then sand for a perfect finish.
Please post pictures when available,
good luck with this project.

 

I would buy some 45 minute drywall powder that you mix in a bucket with water. It dries harder and can probably fill these notches better. I would mix a batch up and take a 6 inch knife and apply the mud with the 6" side of the knife parallel to the corner bead and drag the knife towards the wall. Try to fill these voids with this mud so it will give you a better base for when you run your knife perpendicular to the corner bead to feather it out. I know that you can fill smaller gaps in drywall with this mud and hopefully it will do the same thing in your situation. I would think 1 or 2 coats of this would give you a pretty flat surface to feather out. One thing I would not do(from experience) is just put a bunch of mud on and then try to sand it smooth, not fun and hard to get it smooth by sanding a big glob of mud.

 

Our guys use the quick dry plaster to do the initial fill of the arch corner bead. It's a lot harder than drywall compoint.

They mix it a little thick so it doesn't settle and fall through the holes.

They just put it on thick enough to fill the holes then, once hardened, they go over it with regular drywall mud.

It always turns out well and we haven't had to go back and fix any.

 

http://www.diychatroom.com/attachment.php?attachmentid=14431&stc=1&d=1256588628

i know its been awhile but can someone tell me what i should do with this.

im pretty sure i need to add mud to this but do i do it with the fast mud that some of you are suggesting. ( i have already filled it with green mud)
what could i use to sand it with?

 

The picture isn't very clear, and i'm not sure of the angle.
Can you post a different angle, or a high res picture?

 

You can use either type of mud. The setting type doesn't shrink as much which may save you another coat. Sand with a sanding "sponge".....

 

I hung the rock in our house and had several arches and barrels....same issue. I sent this sketch to a guy on another site (forgot which one). The feedback I got was basically "don't drag the knife tight along the arch bead, leave a small gap so you get a small thickness of mud covering the notches, then take some extra care with the sanding". I still haven't finished all my arches.

 

Yeah, but the pic looks like normal mud "shrinkage" where the cuts are in the bead, not the knife hit the notches. The technique described is correct. And use a knife that is wide enough (8") to make sure you span the notches. Hand sanding with a sponge will take care of the rest.......