# What's your technique to avoid bubbles?



## eonian (Aug 16, 2020)

I am now taping the lofts in my shed and thought I'd be able to tape without bubbles by now. My loft walls aren't long or high. While I'm much better at taping than when I started, I was pretty disappointed to find a bubble in a tapered seam. I made a conscious effort not to pull too hard or too much mud out (at least I thought), but I still have a bubble albeit a small one. 

Early on, my mud was compromised and was drying out faster than I could get tape up. Some bubbles were probably caused by pulling out too much mud. By now I am much more efficient with my tools and have a good feel for how long I have to work with the mud. I can lay some dang smooth mud with a 10" trowel, 6" or 12" knife, but I guess I can't tape without a bubble to save my life. 
On a positive note, making so many tape bubbles has made me more proficient in finding them, sometimes by the way it sounds running my finger over the tape. I have gotten a lot of practice in fixing the smaller bubbles by cutting them into a remud. If the bubbles are large/long or cross the joint, I pull and retape but sometimes still wound up with bubbles retaping. 

I think many of you seasoned drywallers may not need to give bubble prevention much thought when taping, but what were the techniques or thoughts you used to avoid them?


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## mark sr (Jun 13, 2017)

Some say it helps to wet the tape first although I never have done so.
As you undoubtedly know the bubbles are caused by not enough mud under the tape. If you catch it will the mud is still wet it's an easy fix. Once dry you usually have to cut the bubble out. I really like FibaFuse. I think it would be difficult to get an air bubble with it.


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## eonian (Aug 16, 2020)

Thanks for your reply!
When I began this project, I started using a spray bottle to dampen my tape and it did seem to reduce the occurrence of bubbles. I think I still ended up with some because I was pulling too much and using too much pressure. Then the damn spray bottle broke and I haven't gotten another one. 

I've read good things about FibaFuse and understand it makes for stronger drywall. The next time I get a chance to finish new drywall, I would like to try it out. I have obsessive tendencies though and don't like feeling as if I've been bested by paper tape!



mark sr said:


> Some say it helps to wet the tape first although I never have done so.
> As you undoubtedly know the bubbles are caused by not enough mud under the tape. If you catch it will the mud is still wet it's an easy fix. Once dry you usually have to cut the bubble out. I really like FibaFuse. I think it would be difficult to get an air bubble with it.


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## jeffnc (Apr 1, 2011)

Spraying paper tape with water and other gyrations to avoid bubbles makes no sense when you can just use FibaFuse. For some reason (I think I know why) it's harder to get a bubble in a corner than on a flat seam, so I still use paper tape in corners. FibaFuse also works there but you should only use a corner knife with it.


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## RustNeverSleeps (Sep 26, 2015)

My somewhat novice advice:
1) Wetting paper tape will lessen the adhesion. A piece of paper saturated with water will absorb less joint compound and therefore not be as well adhered. It probably does not matter in most cases, but I sort of noticed that on a couple of my projects and later watched someone do a video demonstration about it, ripping up some joints after they had set. The pre-wet tape was much easier to tear out as compared to the dry tape. 

2) You may want to prefill the joints before taping, especially if they are of any depth or width. Using quick set or regular compound if you have the time to wait. Then as a second step apply tape over a more even surface, allowing for a more uniform application.


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## jeffnc (Apr 1, 2011)

RustNeverSleeps said:


> 2) You may want to prefill the joints before taping



How can you not prefill joints when using paper tape? It's not optional.


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## Clutchcargo (Mar 31, 2007)

I've come across the same thing while taping. I've made it all the way to primer before a bubble revealed itself :vs_mad:. I tried wetting the tape; it makes the knife slide easier but I believe it reduces tape adhesion and can cause bubbles. What I've been doing for my patches, where I cut out the bubbles, is soak the piece of tape in the mud. It seems to bond much better.


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## jeffnc (Apr 1, 2011)

Clutchcargo said:


> What I've been doing for my patches, where I cut out the bubbles, is soak the piece of tape in the mud. It seems to bond much better.



This is the idea behind banjos, but obviously that's overkill for this.


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## Clutchcargo (Mar 31, 2007)

There's also one that sits on the edge of your bucket and guides the tape through the mud so it's covered as you pull tape. 
Just like most drywall tools like this, it's unnecessarily expensive.


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## Old Thomas (Nov 28, 2019)

I put the tape in a bucket of water. I put on a thin coat of compound, lay in the tape, then trowel it out. Wet tape doesn’t suck the moisture from the compound. A banjo with diluted compound makes the tape wet, duplicate that process.


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## u2slow (Feb 9, 2012)

Mesh tape for me. No bubbles. :biggrin2:



I'm no drywaller, but sometimes I gotta do drywall.


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## eonian (Aug 16, 2020)

Thanks for your reply.
I invite you to TX to marvel in my ability to bubble corners as if it's going out of style. :biggrin2: Corners were where I had the most trouble with bubbles both in frequency and span. I'd like to hear your reasoning though in case it's insightful.





jeffnc said:


> Spraying paper tape with water and other gyrations to avoid bubbles makes no sense when you can just use FibaFuse. For some reason (I think I know why) it's harder to get a bubble in a corner than on a flat seam, so I still use paper tape in corners. FibaFuse also works there but you should only use a corner knife with it.


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## RustNeverSleeps (Sep 26, 2015)

jeffnc said:


> How can you not prefill joints when using paper tape? It's not optional.


Optional?...if anything I was suggesting doing it twice. 
I am speaking of prefilling the joint and let it dry before taping, so there is a flatter and more uniform surface to apply paper tape afterwards. Of course that introduces the issue of then not having enough joint compound under the tape if one is trying too hard to avoid building up a hump. (So the joint is filled a second time). When doing wall repairs in my home I find it works better to get any deep crack patched before taping, rather than combine the steps, even if it is a narrow crack. 

But maybe we are talking past each other. It is hard to interpret your terse reply, whether you are trying to offer advice or add snark. Maybe you suggesting that all joints, including butt, tapered, misc repairs should be prefilled and left to setup before beginning any taping. No matter what the joint looks like before taping. But this is what I thought many drywall installers did, especially with the fiber or mesh tapes.


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## mark sr (Jun 13, 2017)

u2slow said:


> Mesh tape for me. No bubbles. :biggrin2:





If you use mesh tape it's best to cover it with a setting compound to lock it in place. Mesh tape has a high failure rate when used with regular j/c.




Only the wider gaps [if any] need to be prefilled and allowed to dry before you tape. I think maybe the reason for less bubble issues on corners is you are going slower than where you flat tape.


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## finisher65 (Apr 7, 2019)

Spreading the mud evenly & fairly thick then a motion to smooth it out before embedding the tape works fine for me. If you're doing a decent length of seam cut the edges of the mud tight on each side as you go, keeps it from drying & leaving a thick edge. 
If you have enough mud on the wall it's pretty hard to wipe enough out & cause a bubble in a tapered joint. 
I rarely prefill.


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## jeffnc (Apr 1, 2011)

RustNeverSleeps said:


> Optional?...if anything I was suggesting doing it twice.
> I am speaking of prefilling the joint and let it dry before taping, so there is a flatter and more uniform surface to apply paper tape afterwards.



Oh I see what you mean. I don't think that's a good idea. First of all, I really don't understand your final point. How can any surface be more flat than the drywall surface to begin with? Whether a tapered joint or butt joint, the drywall is very flat to start. Maybe you're talking about the little crevice between the boards. This really shouldn't be an issue as it should be pretty inconsequential to the application of 2" wide tape.

For a tapered joint, I would fill the joint with compound and then embed the tape within that. This is the strongest joint with the least buildup. For a butt joint obviously there is going to be a ridge of buildup, but the last thing you want to do is apply a coat before the tape that the tape can't sink into. Butt joints are all about doing everything we can to make that ridge less noticeable. That's why they need to get feathered out for a total of about 20" wide.


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## jeffnc (Apr 1, 2011)

eonian said:


> Thanks for your reply.
> I invite you to TX to marvel in my ability to bubble corners as if it's going out of style. :biggrin2: Corners were where I had the most trouble with bubbles both in frequency and span. I'd like to hear your reasoning though in case it's insightful.



Hmmm. Well when applying paper tape to a flat joint, you have a 2" width that a bubble can get trapped under. So it's easier to get a bubble in the middle. A bubble on the edge should be pressed out. It's only when there is a barrier to keep the air from escaping that a bubble forms. So if there is a 1/2" wide bubble in the middle of 2" paper tape, that leaves 3/4" of joint compound holding down the tape, and it's very difficult to press the air bubble through that when your taping knife passes over it.

However in the corner, you are only dealing with 1" width of paper on each side. So a bubble is more likely to be very close to the edge, which is easy to press out. My only guess is that you're not putting enough compound on before the applying the tape, which makes it harder to press down and squeeze those bubbles out, if any exist. It could also be that you're applying the compound in globs in your corners, rather than a more smooth coat on the flat walls. Hard to say without watching you work.


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## mark sr (Jun 13, 2017)

The only time you need to prefill a joint is when the gap is large enough where any mud put in it during the taping process will sag down putting a protruding 'ridge' in the tape.


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## RustNeverSleeps (Sep 26, 2015)

jeffnc said:


> Oh I see what you mean. I don't think that's a good idea. First of all, I really don't understand your final point. How can any surface be more flat than the drywall surface to begin with? Whether a tapered joint or butt joint, the drywall is very flat to start. Maybe you're talking about the little crevice between the boards. This really shouldn't be an issue as it should be pretty inconsequential to the application of 2" wide tape.
> 
> For a tapered joint, I would fill the joint with compound and then embed the tape within that. This is the strongest joint with the least buildup. For a butt joint obviously there is going to be a ridge of buildup, but the last thing you want to do is apply a coat before the tape that the tape can't sink into. Butt joints are all about doing everything we can to make that ridge less noticeable. That's why they need to get feathered out for a total of about 20" wide.


I accept all that as best practice. I may have been over thinking the question, in my home situations I was not doing as large a job as say adding a new room; but making smaller repairs due to water damage, mildew damage, cutting holes to access pipe runs in the wall, etc. There were pretty big gaps at the ceiling and sometimes at repair junctions. Though the big gaps were first filled with quickset before taping with all purpose.


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## jeffnc (Apr 1, 2011)

RustNeverSleeps said:


> Though the big gaps were first filled with quickset before taping with all purpose.



That works.


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## ront02769 (Nov 28, 2008)

Many ways to neaten up a wall. but If the op is just a homeowner doing a one-off some don’t make any sense....like buying a banjo Nd having at it. For just basic paper tape, most around here just thin the initial coat of mud and lay it with a 6” trowel and then run over it with same thinned mud. No worries, no bubbles. For the mesh tape, we just mix up 30 min set and bed it it. Again, no bubbles.


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## JLawrence08648 (Mar 1, 2019)

I've used Fibafuse and it works well however you have to be careful sanding too close,

Wet the tape for 20-30 seconds, lay a thin coat, put the tape on, run your knife over the tape, this will remove or eliminate any bubbles, now put your top coat on.


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## jeffnc (Apr 1, 2011)

JLawrence08648 said:


> I've used Fibafuse and it works well however you have to be careful sanding too close


On the contrary, I've found that's one of the benefits of using FibaFuse. With regular mesh tape, it just can't be sanded. So you'll see a grid mark if you sand too much. With paper tape, it will fuzz up, leaving a different kind of paint finish problem. FibaFuse itself can actually be sanded to a certain extent, and once painted you will usually not see any problem if you sand a little too close on some spots with it.


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## JLawrence08648 (Mar 1, 2019)

jeffnc said:


> On the contrary, I've found that's one of the benefits of using FibaFuse. With regular mesh tape, it just can't be sanded. So you'll see a grid mark if you sand too much. With paper tape, it will fuzz up, leaving a different kind of paint finish problem. FibaFuse itself can actually be sanded to a certain extent, and once painted you will usually not see any problem if you sand a little too close on some spots with it.


Mesh tape - Agree, I use to use it for wide gaps and cracks, now Never, When I have a wide gap or a crack I use Fibafuse; Fibafuse - Agree somewhat, You have to be careful, Agree to your "to a certain extent", I have not used Fibafuse extensively or exclusively, I use it for wide gaps and cracks; Paper tape - The old tried and true. I'm very comfortable with it and see no drawbacks if done correctly.


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## jeffnc (Apr 1, 2011)

JLawrence08648 said:


> no drawbacks if done correctly.


Right, and that's really the key to so many building practices in the trades. Some of the older techniques can work well, but some newer techniques can be faster, less expensive, and require less skill and still get it right.

For example, with FibaFuse, you _can_ use it in corners_ if done correctly_, but it's easy to tear if you're not careful. I still use paper in corners for that reason.


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