View Full Version : Tapered Edge Taping Problem

leon bee
12-12-2003, 08:40 PM
Hello: I'm not a real rocker, but I do an awful lot of it- additions and remodels, etc. My butt joints are invisible, and my inside corners, (with modern materials) are perfect. But the last couple of years I've been having trouble with the long edge. I always rake too much mud out, then it seems to shrink a little more. Then, like on a smooth ceiling, I'm hitting it over and over again to leave the surface flat.

I only really noticed this the last few years, like since I switched over to lite compound. I like my Marshalltown knives, but I figured out they must be too flexible, or my technique has changed without me knowing it. I must need a real stiff knife, or maybe I should try a trowel. Or try to leave a ridge in there on the second coat.

Sorry to be so wordy, but if any of y'all would comment I would sure appreciate it.

Mike Rooney
12-12-2003, 09:44 PM
You want your knife to be flexible (atleast I do). Lay it on alittle heavy onthe block coat and pull it tight on the skim coat. All I do these days is remodelling, so I usually hit the flats and nails an extra time to cut down on sanding - all we do is smooth here.

Bill P
12-13-2003, 07:44 AM
Hi Leon,

It sounds like you might want to give the finish coat(s) some time to give up moisture to the previous coats before you strike off. This firms up the compound so a low angle pass won’t drag material out. It also softens minor high spots so you can knock them down.

If you’re having good luck with butt joints, you must be using this technique with them.

Good Luck

leon bee
12-13-2003, 11:42 PM
Thanks guys, I went back over there today and got some good light on the ceiling and really studied what I was doing. Bill P., do you mean like put a heavy coat on then drink coffee for a minute before you knife it down? I tried that and I think it will help me a lot.

Bill P
12-14-2003, 08:19 AM

That’s the idea. Experiment with the time to see what works best for you and the current humidity. Could be you’re moving faster than you did before this problem developed.

I find the mud I strike off is too thick to work well and working with heavy mud really slows down the process. I keep two buckets going all the time. A “source bucket”, which is thinned mud to apply to the wall and a “used bucket”, which is where I dump the firm stuff I strike off the wall. At the end of the day, I mix water with the firm stuff and let it sit over night. Next day I adjust the consistency and repeat the process. Both buckets set on a cart that I move around the room. The height is ideal for working from stilts.


12-14-2003, 02:45 PM
Seams cannot be always perfectly straight because the framing is not. One tries his best to get them straight, but many times it's impossible. Suggest on your 2nd coat you do not thin the mud thus less shrinkage. Try to bend your knife a little on the 2nd coat too and then for the final coat thin it. Keep the 10 or 12" knife for the final coat at the smallest angle possible with very little pressure on it. By the way, vertical seams are never straight - just cannot be done!

Mike Rooney
12-15-2003, 08:48 AM
What are these guys talking about?

12-28-2003, 02:35 PM
I dont want to gice wrong advice here but i like using a flexible knife on my first bed coat and use a little stiffer (blue steel) knife on my finish coat. i feel that if you can get a nices flatter skim with a wide stiff knife. just my opinion. The flexible knifes are good to put pressure with when bed coating in my opinion.


Myron Ferguson
01-08-2004, 03:06 PM
For my fill coat I use a beveled trowel. It leaves the desired crown, a little for shrinkage and a little for sanding. It measures 14" by 4 1/2". My final coat is just a skim coat and I use a wide taping knife for that.

leon bee
01-15-2004, 11:50 PM
Today I tried a drywall trowel I spotted at a supply house over in the city. Think I am going to like it a lot. This was my second coat, what I guess you guys are calling the block or fill coat. Real nice and flat.

01-25-2004, 08:22 PM
Switch back from the lightwieght. I fthat is when your prob started.