Hi all I’m fairly new to all this so bear with me.....so I’m doing a finishing job for a friend of mine and the guys who hung the drywall left big gaps at the seams and they filled the gaps in with joint compound that has since dried...so my question is can I Tape over the seams that they put compound into? And it still look good in the end? Any help is greatly appreciated.
Drywall Taping
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Make sure the tape coat is good and dry before you apply the 2nd coat of j/c. You don't want the weight of that mud to pull the tape loose. Air bubbles under the tape never go away - you need to cut them out and either fill with mud or retape. Thinning the mud slightly makes it flow/slide better.
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To expand on what Mark Sr said, no need to sand between coats. You are only concerned with what is sticking out. When you're getting ready for your next coat, take a 6" or 8" drywall knife and with light presssure, scrape off any ridges that stick out til they're flush. Then apply your next coat. Sand after the final coat. Prime the new areas and check for anything you missed. You might see some small pinholes left from air bubbles, or an edge of an area you didn't sand properly. Go ahead and fix those and then paint.
Mike Hawkins
Mike Hawkins
Proud: something that sticks up or out above something else.
Shy: something that is below or short of something else.
You want all the drywall screws to be shy (i.e. countersunk properly). You can determine this by taking your taping knife and sliding it across all the screws. If you get stuck or hear metal scraping, then you have a proud screw. It needs to be screwed in a bit more.
etc.
I wouldn't call that a "tip", I'd call that a necessity of the process (unless using setting compound.) You want to be doing the least amount of sanding possible. The better your taping job, the less sanding you'll do.
Since there are issues with paper tape, I'd recommend using FibaFuse (not to be con"fuse"d with FibaTape.)
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I wouldn't discourage beginners from sanding between coats of mud. It's often required when one is learning to finish.
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What are your thoughts on using fiberglass, self-adhesive, mesh tape, versus paper tape? I love the mesh tape, I find it MUCH easier to use. But I've been told that "if you're using mesh tape, it means you don't know what you're doing".
Mess tape needs a setting compound applied over it to lock it down. It's prone to 'wrinkle' [not necessarily right away] when just regular premixed joint compound is used. Many pros successfully use mesh tape for repairs [it speeds up the process]
For the most part, regular fiberglass mesh tape is "amateur hour". It's used by DIYers and "pros" who are not full time drywallers who don't know what they're doing. There are actually very few circumstances I would use that tape (now that there is a third option, I never use it.)
Mesh tape is weaker than paper tape. Therefore you need to use setting compound with it to achieve full strength rather than standard drying joint compound. If you have to mix your own compound, then where did the convenience of mesh tape go? Out the window.
Paper tape can be more difficult to use for DIYers since it can trap bubbles and form weak spots or high spots that are a problem when sanding and painting. It is strong if done correctly.
Another product called FibaFuse solves these problems. It is as strong or stronger than paper tape, but with almost as much convenience as pre-sticky mesh tape. I recommend it for all taping except for corners (it can be used in corners, you just have to be more careful with it. I still use paper for corners myself.) It's a finer weave than mesh tape, but compound will still flow through it. So once you stick it on with a few dabs of compound, you can tape over it just like mesh tape, if you prefer, without having to lay a base layer like with paper tape. I usually lay a base coat, but you can't really get bubbles like with paper tape.
The second great advantage of this stuff, over both paper tape and mesh tape, is that you can sand it. With paper or mesh, if you sand down to the tape, you're kind of screwed. This stuff is no problem.
Not to be confused with FibaTape - it's FibaFuse.
https://www.lowes.com/pd/Saint-Goba...x-250-ft-Mesh-Construction-Joint-Tape/4411371
Mesh tape is weaker than paper tape. Therefore you need to use setting compound with it to achieve full strength rather than standard drying joint compound. If you have to mix your own compound, then where did the convenience of mesh tape go? Out the window.
Paper tape can be more difficult to use for DIYers since it can trap bubbles and form weak spots or high spots that are a problem when sanding and painting. It is strong if done correctly.
Another product called FibaFuse solves these problems. It is as strong or stronger than paper tape, but with almost as much convenience as pre-sticky mesh tape. I recommend it for all taping except for corners (it can be used in corners, you just have to be more careful with it. I still use paper for corners myself.) It's a finer weave than mesh tape, but compound will still flow through it. So once you stick it on with a few dabs of compound, you can tape over it just like mesh tape, if you prefer, without having to lay a base layer like with paper tape. I usually lay a base coat, but you can't really get bubbles like with paper tape.
The second great advantage of this stuff, over both paper tape and mesh tape, is that you can sand it. With paper or mesh, if you sand down to the tape, you're kind of screwed. This stuff is no problem.
Not to be confused with FibaTape - it's FibaFuse.
https://www.lowes.com/pd/Saint-Goba...x-250-ft-Mesh-Construction-Joint-Tape/4411371
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I don't know if this will help on which tape should be used.
Quote: " Repeated joint strength tests conducted at the USG research center have shown that joints taped and finished with conventional fiberglass leno-weave mesh tape and conventional joint compound are more prone to cracking than joints finished with paper tape and conventional joint compounds. This is because fiberglass nesh tapes tend to stretch under load, even after being covered with joint compounds."
" Permanent repair of these cracks is difficult. Accordingly, USG does not recommend using conventional fiberglass leno-weave mesh tape with conventional ready-mixed, powder or chemically setting compounds for general drywall joint finishing."
Quote: " Repeated joint strength tests conducted at the USG research center have shown that joints taped and finished with conventional fiberglass leno-weave mesh tape and conventional joint compound are more prone to cracking than joints finished with paper tape and conventional joint compounds. This is because fiberglass nesh tapes tend to stretch under load, even after being covered with joint compounds."
" Permanent repair of these cracks is difficult. Accordingly, USG does not recommend using conventional fiberglass leno-weave mesh tape with conventional ready-mixed, powder or chemically setting compounds for general drywall joint finishing."
Yes of course Clarence, every real pro drywaller knows that, but I've probably never met a DIYer who does. It's not just the stretch in the fibers, it's also the large gaps in the mesh. Just too much space between the reinforcing elements.
Paper tape makes a strong bond because the holes in it where the joint compound embeds are very small. Mesh holes are gigantic in comparison. And while it might seem counterintuitive, drywall itself is strong because of the paper. If you have any doubt about that, think about how you cut drywall. You don't use a circular saw like you would plywood. You simply score the paper with a utility knife. Then the drywall will literally fall apart by itself by its own weight if you merely pick it up. Paper is what gives drywall it's shear strength.
Paper tape makes a strong bond because the holes in it where the joint compound embeds are very small. Mesh holes are gigantic in comparison. And while it might seem counterintuitive, drywall itself is strong because of the paper. If you have any doubt about that, think about how you cut drywall. You don't use a circular saw like you would plywood. You simply score the paper with a utility knife. Then the drywall will literally fall apart by itself by its own weight if you merely pick it up. Paper is what gives drywall it's shear strength.
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It may be less effort to learn to apply mud correctly but we're talking about people who haven't had the experience to teach them that.
This forum is rife with threads of drywall work that would have benefited from sanding after the 2nd coat of mud, not the tape coat.
In fact often the advice is that more sanding should have been done before priming.
Scraping a ridge here and there works for experienced people but the beginners typically have a lot more to deal with than that.
Hardly anyone likes to sand drywall & most finishers consider it a reflection on their work, but the goal is to provide a high quality product, so the inexperienced typically have to a bit more sanding work to do.
That is the reason for this forum's existence!
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