# Taping and seams



## Nestor_Kelebay (Jun 17, 2008)

Here's what you need to know:

Non-Chemical set drywall joint compound comes in three flavours;

1. "Regular" or "Taping" joint compound:
This kind has the most glue in it so that it sticks well to the drywall and the paper. It also dries the hardest, and is therefore the hardest to sand smooth. Only use this kind to set your tape in and to cover that tape. After that, you can use either one of the two following joint compounds:

2. "Finish" or "Topping" joint compound:
This kind of joint compound has the least amount of glue in it so it dries the softest and therefore the easiest to sand smooth. Use this kind for all subsequent coats after taping.

3. "All Purpose" joint compound:
This kind of joint compound is about half way between Regular and Finish so far as glue content goes. It's meant for drywall contractors doing repair work so that they don't have to lug two different compounds around with them everywhere they go. You can use All Purpose after you do your taping instead of Finish joint compound. It'll just be a bit harder to sand smooth.

The box or bucket your premix comes in should tell you whether it's meant to be used for taping, finishing or as an All Purpose joint compound.

Every premixed joint compound will be very thick. The mix it thick at the factory because they know you can thin it yourself to make it easier to work with, and no one wants to pay for shipping water. So, don't be afraid to thin your premix with water to make it easier to use.

Chemical set joint compounds only come in a powdered form (so far as I know) because as soon as you mix them with water the chemical set process starts, and the stuff will be hard as a rock before it even leaves the factory.

If you plan to use fiberglass mesh tape instead of paper tape, it's important to use a chemical set joint compound for your first coat. That's because the chemistry by which the chemical set happens results in a harder and stronger joint compound. Since fiberglass mesh tape is a little weaker than paper tape, it's recommended to use a chemical set joint compound when using fiberglass mesh tape to compensate for the weaker tape with a stronger joint compound.

Chemical set joint compounds will typically have a number in their name, like Synko ProSet 90. The "90" refers to the number of minutes after mixing the powder with water that the chemical set kicks in. Once the chemical set kicks in, then within a few minutes your joint compound will go from easy to spread to stiff and unspreadable. NEVER try adding water to chemical set joint compounds to make them workable after the chemical set starts to kick in. You'll just be making the compound weaker.

People in here have been praising a kind of tape called "Fibafuse" or something like that. They say it's better than fiberglass mesh. I've never used the stuff, so I can't comment. But other people will be in here before long to give their opinions on it.

And, ALWAYS ALWAYS ALWAYS when working with joint compound or plaster, have a bright light shining on your work at a sharp angle to exagerate the roughness of the surface. That "critical" lighting will tell you whether you need to add more joint compound or remove it to make for a flatter smoother wall. Use the light when both spreading joint compound and when sanding it down.

For your first coat, I've always found it better to use a tungsten carbide bladed paint scraper to scrape any excess joint compound off than to sand it off. The paint scraper removes the excess joint compound quickly and easily. The kind of dust scraping produces is bigger and falls straight down so that it doesn't create the problems that sanding dust does.

Finally, for butt joints or wherever you don't have a contour on both sides of the joint, use a "Curved Trowel". A curved trowel looks like an ordinary 11 inch plastering trowel until you sight along it's edge or set it down on a flat surface and realize that the blade of the trowel is curved. It arches up so if you set it down on a flat surface, it's about 1/8 of an inch off the surface in the middle of the trowel. Since you hold it at a comfortable angle when using it, a curved trowel allows a total newbie to spread a perfectly symetrical mound of joint compound over a butt joint that's about 5/64ths of an inch thick in the middle of that mound. That's plenty thick enough to bury joint tape in, but not thick enough to cause a visible "bump" in the wall, even if you have wall mounted light fixtures. You should be able to buy curved trowels at most home centers and at every place listed under "Drywall & Plastering Equipment & Supplies in your yellow pages phone directory. They cost about $20 to $25 each.

Hope this helps.


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## ront02769 (Nov 28, 2008)

Use, the green and put a half c of water in it and mix it well.....or use the dry 90 set and mix small quantities to the consistency of sour cream. No need for the light thing as you are just taping. Put a bunch of mud along the joint, lay the tape on it, bed it in with a six inch knife, and then put another layer of mud on top and smooth off. Ron


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## Gary in WA (Mar 11, 2009)

"Conclusion With ready-mixed (drying-type) compounds, papertape
must
be
used
to
ensure
good
joint performance.
 With setting compounds, either paper tape or fiberglass mesh joint tape can be used; however, paper joint tape performs best"
from; http://www.usg.com/content/dam/USG_...rywall-finishing-technical-guide-en-J1990.pdf

4.6.7.1 gaps not greater than 1/8" filled with either type, drying or setting compound. 
4.6.7.2 Gaps greater than 1/8" shall be prefilled with setting type compound
From; http://www.lafarge-na.com/GA-216-07_English.pdf

Gary


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## AlphaPilot (Aug 6, 2012)

So after working on the walls this evening it took me two tries until I figured out how the taping can be done.

On the tapered joints, if I put in a 4" thick bed of mud for the tape and go to squeeze the mud out from behind the tape I have to really push hard on my drywall knife to get it to form into the concave "tapered" joints. So am I supposed to apply such a liberal amount of mud so the joint is completely flat, and then lightly squeeze the mud out from the tape? I thought about doing that, but then the tape is actually floating in the mud and not glued to the paper facing of the drywall? Plus it means my next two coats will form a bump which defeats the tapered edge I'd say.

@nester_kelebay
That knife sounds interesting but I am not sure if I follow 100%. It apparently is for only butt joints (because of my problem with the concave joints) Is it tapered so the knife is held centered on the joint? And is it to be used prior to setting the tape or supposedly only used after the tape is set to get that first top coat on the tape? There is a lot of different ways I am sure, I am looking for the best technique to learn or at least easier technique to learn!
@RonT that sounds pretty straightforward and is what I have done so far
@gary is the setting type compound the green bucket, or only the chemical reaction type of mix? I definitely don't want to use the wrong stuff in a big gap and have it crack in a few years.


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## Nestor_Kelebay (Jun 17, 2008)

Alpha Pilot:

You are certainly not the first homeowner who has had trouble learning how to use paper tape. It takes years of practice to make using paper tape look easy.

People are going to bark at me for saying this, but you very well might be better off using that fibafuse tape and a chemical setting joint compound. You won't find much difference between joint compound with a chemical set and premixed joint compounds except that the chemical set comes as a powder that needs to be mixed with water.

You simply mix it up to an easily spreadable consistency, and spread it over your already taped joints.

Here's what a curved trowel looks like:










Notice the curvature on the blade? If not, hold a straight edge on your computer screen and align it with the front and back corners of that trowel. I think whomever made this picture enhanced that curvature because normally the curvature is so slight as to not even be noticable.

That curvature allows you to spread joint compound over joints where you don't have a contoured edge on both sides. It makes dealing with butt joints and joints where only one side of the joint has a contour much easier. You COULD use a curved trowel to bury any mess you make with paper tape, but I think the better option would be just to opt for that fibafuse tape and a chemical set powdered joint compound.


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## AlphaPilot (Aug 6, 2012)

Nester,

I see the curve in that blade. I was thinking more so a notch on one side of the blade that made it easy to mound the mud. That looks like it is held flat and literally makes a hump towards the center.

I am not sure about the fibaflex being sold locally. I don't like how the 'hot mud' has to be mixed every go, and used up then or wasted. I am working every time I have free time but it is sometimes just 30 minutes or 2 hours etc so pre-mix makes it easy to start and stop. I have just heard paper is the best choice time and time again so I was going to avoid any mesh styles.

This guy in this 



makes it looks quite easy of course. But that's the style I think I want to use. I notice it looks to me like he doesn't butter the joints very much before taping horizontals but later he comments on filling those concave areas full so the next two coats are easier. He also doesn't apply mud over the tape. I was embedding the tape, and trying to do a top coat on the tape!


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## ddawg16 (Aug 15, 2011)

Research 'butt boards'. I made my own. Made a world of difference on doing those end joints.

On the corners....I used a plastic knife....using one of those 'corner' tools was useless.


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## AlphaPilot (Aug 6, 2012)

What cons are there with fiber mesh tape? It was a lot easier for me to install and labelling claims it is stronger...? Just want to hear first hand.

When using paper on horizontal... It takes a lot of mud before the paper can be bedded. Makes me worry it is too much mud without support, but apparently it doesn't matter?


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## oh'mike (Sep 18, 2009)

I use all paper---set in 'all purpose' green lid---

I've seen way to many cracks in mesh tape jobs to ever want to use it----

You will want the mud a bit on the wet side to embed the tape.

Next, fill coat, I usually use 90 or 45 minute powdered--

Final coat---light weight (blue lid--)


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## ToolSeeker (Sep 19, 2012)

AlphaPilot said:


> What cons are there with fiber mesh tape? It was a lot easier for me to install and labelling claims it is stronger...? Just want to hear first hand.
> 
> When using paper on horizontal... It takes a lot of mud before the paper can be bedded. Makes me worry it is too much mud without support, but apparently it doesn't matter?


Unless used with setting mud (powder mixed with water) it has no strength and is very prone to cracking. Down side to setting mud is it's a PITA to mix and work with. Your second comment I do not understand, why it takes a lot of mud to embed the tape. You put on a thin coat apply the tape and pull your knife down it to remove the excess. Next coat fills the taper.


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## AlphaPilot (Aug 6, 2012)

Okay, so I can do thin coats with tape on butt joints, but I have a 6", an 8", and larger tools. I use the 6" for the taping and my knife will not touch the tape to squeeze the mud out from under it unless I have the tape protruding enough with the large amount of mud behind it so the blade can run along the surface of the tape. If I just do a thin coat of mud and it's a tapered (horizontal) joint then I can't even get the blade inside the taper where the tape is positioned to remove the excess mud behind the tape. I have a good feeling you guys are using 4" knives on the first coat because that would let me get closer to the tape and joint inside the tapered edges.


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## oh'mike (Sep 18, 2009)

Yep---get yourself a 4"--


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## AlphaPilot (Aug 6, 2012)

Is that what you use Mike? Just guessing that's the solution to the problem.


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## oh'mike (Sep 18, 2009)

6" for setting butt joints--4" for embedding the paper on tapered seams---


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## ToolSeeker (Sep 19, 2012)

I guess I'm lost here I use a 12" trowel to bed my tape. 14" for the next coat or 16" so I'm not getting why your having trouble with a 6". When I used knifes all I used for tape was a 5 or 6".


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## jeffnc (Apr 1, 2011)

AlphaPilot said:


> What cons are there with fiber mesh tape? It was a lot easier for me to install and labelling claims it is stronger...? Just want to hear first hand.
> 
> When using paper on horizontal... It takes a lot of mud before the paper can be bedded. Makes me worry it is too much mud without support, but apparently it doesn't matter?


Mesh tape is weaker, period. USG Green lid is fine for all coats. Using paper tape can be somewhat of an art form to do it correctly. The reason I recommend you use all All Purpose joint compound is that it will sand consistently. If you use a mix of taping, setting, and lightweight, the 3 layers will sand at different rates and it can be difficult to get perfectly smooth. All Purpose compound will be plenty strong as long as you don't use mesh tape.

Save yourself the time and learning curve. Use FibaFuse. It will solve all your problems. It can be hard to find right now, but probably in a few years it will be almost all people use. Except that it can be a little finicky in corner taping.


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## Jmayspaint (May 4, 2013)

jeffnc said:


> Save yourself the time and learning curve. Use FibaFuse. It will solve all your problems. It can be hard to find right now, but probably in a few years it will be almost all people use. Except that it can be a little finicky in corner taping.





I recently switched from mesh/setting compound for repairs to Fibafuse and all purpose. 

Not to be confused with Fibatape, which is much more available, but is just the Fiba brand of mesh tape. Fibafuse is a fiberglass mat tape not a mesh. 

So far I'm very pleased with the results. I haven't tried an inside corner yet, but other than its lack of adhesive (has to be bedded like paper) it's easier to use IMO than mesh. I have read about people using spray adhesive with Fibafuse to mimic the self adhesion of mesh tape. 

I also think there is an advantage to being able to use all purpose mud instead of setting compound. No mixing, time limits, or differences in hardness of the mud layers. 

Now, I only use setting compound when time limits demand it. 


Sent from my iPhone using Tapatalk


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## ToolSeeker (Sep 19, 2012)

I have also switched to FibaFuse it's better than paper (except corners) which makes it about 100 times better than mesh.


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## jeffnc (Apr 1, 2011)

And if you use a corner trowel, like I recommend DIYers do, then FibaFuse really isn't a problem for corners either.

For setting FibaFuse, I just put a few dabs of compound along the joint. That's enough to hold the tape in place as I mud over it.


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## AlphaPilot (Aug 6, 2012)

So when setting the tape you don't try to get it close to the joints but instead just flush andon top of the bevel joint. Since the fiber mesh tape is adhesive and stuck to the joint I figured tape would be similar and should be close to the joint instead of built out from the bevel.

I'll have to try trowels. The curved one looks handy.


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