# First time taping - Tape has air under it



## theedudenator (Dec 5, 2009)

I am doing a rather large drywall repair.
I cut the existing drywall to the nearest studs.
I then fit my new piece in and screwed.

I put a thin layer of mud, then tape, then mud again. With a large taping knife.

After an hour or so, I can see the tape trying to lift.
Is this normal?


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## jlhaslip (Dec 31, 2009)

not normal.
I would suggest cutting out the air bubbled tape and reapplying more mud/tape.
don't squeeze the mud too hard.


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## chrisn (Dec 23, 2007)

Next time put down a thicker first skim, embed tape in that well and let it dry before applying additional layers of mud


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## Willie T (Jan 29, 2009)

It helps to teach yourself "why" you are even using this tape. It's not decoration. It has a structural function just as the foundation of a house does.
· Is it to fill the gap between the two sheets of drywall? ...No.
· Is it to level out the surfaces? ...No.
· It is to create a solid, continuous surface bond between the two sheets that will show no cracks when small shrinkage and settlement movements occur in the future.
So............ Your main purpose is to allow (or "help") the three elements of...
1. The paper on the face of each sheet
2. The tape, itself
3. The mating coat of mud
... to combine smoothly as a unit... adhere to one another... and dry as a hard, solid bridge upon which to build additional layers of finishing compound (mud).

You do this by, first of all, making sure everything will stick together in more than just a physical, surface bond. You are looking for a chemical adhesion. You do not have to worry about creating a substance that will do this. It's already been created, and it's called "mud" (Drywall Compound).

But you DO have to provide the proper environment and application process for it to do it's job correctly and fully.

This means (believe it or not) that you have to provide additional moisture for the chemical elements in the mud to do their thing.

Step one is to mix your taping mud a little on the sloppy side. The consistency should not be like butter or mashed potatoes... but like mashed potatoes with a big hunk of butter mixed in. The way your kids like to do it at Thanksgiving dinner.

Secondly, this mud is laid into a "prepared surface". Too big a gap between sheets, chunks missing from edges, and paper scraped off the surface of the sheet are bad. They draw water out of the mud too quickly, leaving a dry surface that will not glue itself down right. They also provide huge areas for the mud to shrink into, instead of staying where it is needed... up on the surfaces, helping all three elements combine as one sheet. All these problem areas need to be filled with mud, and left to thoroughly dry hard before you begin taping. 

Now you can go on to step two. This is the process of spreading a “thicker than necessary” layer of mud down the strip to be covered with tape... and it needs to be wider than the tape that will cover it. You want plenty of mud on there.

Next, we consider water. Do you know some guys even quickly wipe a wet sponge across the joint before applying mud because moist surfaces are that important for good adhesion? I don’t do that, but I do religiously follow this next procedure.

I keep a bucket of clean water at hand to not only keep all my tools wet, but to also moisten the tape before application. After I cut a piece of tape to length, I loosely wrap it around one hand. I dip this hand (with the tape wrapped around it) into the bucket of water for about a half a second. Just dip it in, and pull it out. Then I proceed like you have probably already been doing.

The trick in wiping the tape on is to, one, keep your knife wet, two, tilt it starting at about a 45 degree angle at first, changing to about 15 degrees, three, keep firm (not hard... just solid and firm) pressure against the wall, and four, be certain that you are always squeezing mud out from under the tape as you drag the knife along.

That’s it. I used to also apply some of that excess mud back onto the tape. I've learned it is better not to. You are now at the stage where you want that tape, mud, and paper to all dry together............... THOROUGHLY. Additional mud on top of the tape right now really does little more than prolong the deep drying process. It often won’t hurt anything, but why add more time?

One more thing. DO NOT start applying more mud until the tape coat has dried all the way. ALL THE WAY.

Try this, and I think you will soon begin to be happy with your taping jobs.

*********************
An additional post:

Here are a couple of tips that will help with the DW taping.

First of all use PAPER tape. Don't even look at that mesh screen.

Make your mud for tape bedding sloppier (wetter) than usual.

Apply plenty of mud on the joint... PLENTY!

Cut the length of tape you are going to need.

Wrap it loosely around your hand.

Dip your hand (the one with the tape wrapped around it) into a bucket of water for about a half second.

Start applying your tape a foot or so from the beginning end (with enough tape sticking out TOWARD the beginning end to make it all the way there).

Using a 6" knife (trowel shaped like a paint brush) wipe back toward the beginning end as you hold the rest of the tape steady with your free hand.

Now that you have the first foot of the beginning end of your tape 'bedded', it should be solidly anchored there and stay put with little problem while you begin wiping the tape toward the other end.

Keep your knife wet all the while you are taping by dipping it into the bucket of water.

Hold the knife *almost* perpendicular to the wall surface. Lean the handle forward (toward the untaped run) at about a 45 degree angle at first, changing to about 15 degrees. Push down firmly (but *just* firmly) as you wipe the tape. Your object right now is to force all the mud you can back out from under the tape. If you hold the knife parallel with the wall (flat with the wall), it will have a tendency to 'float' along and leave too much mud behind, under the tape. This is NOT what you want to happen. You want to force all the excess mud out from under the tape that you can.

Keep scraping all the excess mud that collects on the knife back into the pan. Keep your knife clean and keep it wet.

That's pretty much it.

Let it dry, and you will see that because you only allowed a thin coat to remain under the tape, it will shrink into the joint, sucking the tape with it. You probably won't have to sand this coat at all if you were careful to work cleanly.


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## Snav (Aug 20, 2009)

Follow Willi T's advice - all of it! He knows what he's talking about. . . I had your same exact problem, theedudenator, and his advice helped me figure it out, too.

Except, unlike you, I lived with it - I wasn't worried because I was going to heavy texture my walls with mud and now I have to rip it out and redo it all. . . which will suck but it'll have to be done so we can sell the house in the future.


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## Willie T (Jan 29, 2009)

Snav said:


> Follow Willi T's advice - all of it! He knows what he's talking about. . . I had your same exact problem, theedudenator, and his advice helped me figure it out, too.
> 
> Except, unlike you, I lived with it - *I wasn't worried because I was going to heavy texture my walls with mud and now I have to rip it out and redo it all.* . . which will suck but it'll have to be done so we can sell the house in the future.


This is one of the most very basic things I tried to impress upon my crews.

Your current work, in any separate part of construction, has to stand alone as a neat, strong, and finished product. Never, ever let yourself fall into the trap of thinking someone or some future process will make the _questionable_ step you just completed "alright".

If various crews could just understand this important principle, jobs would all turn out so much better.


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## theedudenator (Dec 5, 2009)

This is great!! Some of the typical responses I get in the plumbing/electrical forums is "hire a Pro" and "Do you have a permit"

So what should I do to fix this?
I did wet the tape when I first applied.
My under surface was not perfect
I did try to apply mud on-top of the wet tape.

So I can sand everything down smooth - maybe even going through the existing tape.

Then I can essentially start from scratch? heavy set mud, wet tape and let it dry overnight.

Any other suggestions?


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## Snav (Aug 20, 2009)

I would tear out the old tape, every bit of it . . . and then sand off the old mud so you have a cleaner surface.
Wipe your surface down to clean off mud-dust so you have proper adhesion when you apply it, again. (either wash it with a bit of water or use a tack cloth - I think washing would be more efficient and thorough, though)

Adhere to Willi's tips and advice and practice before you apply it to your real walls. . . Print out his advice or rewrite it in a numbered list so you have clear and precise steps to follow, refer to it often.

I practiced for a while on a scrap sheet of drywall - I took my skill saw and set it to a shallow depth and cut grooves in the sheet, every foot or so - this gave me plenty of room to practice the techniques and to monitor how good (or bad) I was doing. . . I wasn't worried about having buts and grooves to fill in smoothly - I was worried about how to properly wet and apply the tape so I wouldn't have bubbles in it.

At the end of practicing on all the grooves I had it figured out - and I can now apply it to my walls knowing it won't have problems, again.


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## theedudenator (Dec 5, 2009)

Since my joints are in poor condition I should just remove the tape and smooth the existing mud?
Not remove it entirely?

thanks


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## tpolk (Nov 7, 2009)

are you just dealing with a few bubbles? if so cut them out and remud. excellent post willie


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## theedudenator (Dec 5, 2009)

2 joints have a small bubble.

1 joint is half way pulled from wall.
and 1 is in between these...


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## theedudenator (Dec 5, 2009)

I pulled the old tape off the walls.
Used my power sander to smooth everything down.

I followed the directions posted. I must say that the process went much smoother.

I will have to see the results in a day, but so far so good.

I guess I can ask another question now.

This is an older house and I have a transition from new to old drywall.
They are not exactly even. I was guessing I can feather the area out rather wide to try to blend it. 
My largest putty knife is 6", should I get something wider for this?


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## jlhaslip (Dec 31, 2009)

yes. try a 12 inch.


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## Willie T (Jan 29, 2009)

theedudenator said:


> I pulled the old tape off the walls.
> Used my power sander to smooth everything down.
> 
> I followed the directions posted. I must say that the process went much smoother.
> ...


You might want to be careful with the sanding. Disrupted (roughed-up) paper surfaces do not take finishes well. And usually just primer won't help a lot. You often need to apply skim coats of mud to return the paper surface to a smooth finish.

Sanding is not for the paper surfaces of the boards... just the built-up mud. And one of the best things to learn about drywall finishing, early on, is that "the more you put on, the more you have to take off".

Good finishers hardly do any sanding. The reason is that they have learned NOT to apply excessive mud, so it is not necessary. Beginners go through many, many sheets of sandpaper.


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## lazzlazz (Mar 29, 2010)

Willie T said:


> Secondly, this mud is laid into a "prepared surface". Too big a gap between sheets, chunks missing from edges, and paper scraped off the surface of the sheet are bad. They draw water out of the mud too quickly, leaving a dry surface that will not glue itself down right. They also provide huge areas for the mud to shrink into, instead of staying where it is needed... up on the surfaces, helping all three elements combine as one sheet. All these problem areas need to be filled with mud, and left to thoroughly dry hard before you begin taping.


Thanks for the informative & detailed post.

How do you fill the "problem areas" with mud, if they are gaps a little bigger than 1/4" between sheets? Do you just try to neatly fit it into the gap?

Also, is pre-mixed joint compound ok if you're using paper tape? (both under & over the tape) 
Is the pre-mixed joint compound the same thing you're going to use to fill those problem areas?


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## oh'mike (Sep 18, 2009)

LazzLazz--This post had details on the different types of mud for for different phases of taping---
To Wet Or Not To Wet That Is The Question - DIY Chatroom - DIY Home Improvement Forum


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## lazzlazz (Mar 29, 2010)

based on very limited experience:
I've been using the green lid sheetrock-brand premixed joint compound when I tape, and have had no bubbles.
However, I forgot to tape (ahem) on one joint & decided to add tape and used the blue-lid sheetrock-brand premixed joint compound. I got several bubbles. Luckily, I spotted most, pulled up the tape, added more joint compound, and fixed the problem (well, one remains that I'll have to fix). 

I'm wondering whether the different joint compound caused the problem? Any thoughts based on more experience than me?


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