# bubbles under tape?



## nidaho (Jul 26, 2015)

always been a banjo taper and have switched to a bazooka. I never get bubbles under the tape with the banjo. what am I doing wrong with the bazooka, I got about 5 bubbles on the last house. is it possible that it was caused by a new wipe down knife being to stiff or from not keeping enough pressure on the wall with the bazooka and getting dry spots. it seemed that it was always the edge of the tape not the center. thanks for any info


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## cazna (Mar 28, 2010)

Sounds like you just missed a few edges on the wipe down. Or you taped over big gaps and didn't pre fill and lost all the mud, Simple mistake you wont do it next time.


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## VANMAN (Jan 14, 2011)

nidaho said:


> always been a banjo taper and have switched to a bazooka. I never get bubbles under the tape with the banjo. what am I doing wrong with the bazooka, I got about 5 bubbles on the last house. is it possible that it was caused by a new wipe down knife being to stiff or from not keeping enough pressure on the wall with the bazooka and getting dry spots. it seemed that it was always the edge of the tape not the center. thanks for any info


Make sure ur mud is thin enough that's a good start!
U could b right about the wipe down blade being stiff or ur missing bits by not getting the gun on the wall at all times!
Me personally I use a 6 inch knife to wipe the tapes and I know if there is any dry spots when I wipe!
But I think its a dry spot under the tape and when u wipe there is not enough mud to carry through from the part ur wiping to the dry spot so it is only putting mud under the middle of the tape and there is not enough of the mud to get to the outside of the tape!(Hope u understand that):thumbsup: 
Only prefill if big gaps as a gun puts out heaps of mud!:whistling2:


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## Mudstar (Feb 15, 2008)

feel like its ground hog day again.......
http://www.drywalltalk.com/search.php?searchid=1149377


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## VANMAN (Jan 14, 2011)

Mudstar said:


> feel like its ground hog day again.......
> http://www.drywalltalk.com/search.php?searchid=1149377


Beer Day:thumbup:


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## VANMAN (Jan 14, 2011)

I forgot every day is beer day!!:thumbsup:


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## gazman (Apr 29, 2011)

Most probably user error if you are new to the zooka, trust me I know. Check your brake make sure that it is not rolling backwards, if it is you will get air in the tube. 
When you advance your tape be sure that the wheels are rolling or you will get a dry patch. And as you are taping be sure that the wheels are in constant contact with the board.


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## gopherstateguy (Apr 8, 2012)

Any chance you sucked any air through the pump?


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## embella plaster (Sep 21, 2013)

Most likely like cazna said new to it and even tho we must apply pressure there is pushing the tape to hard in leaving no mud on the edge


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## cazna (Mar 28, 2010)

embella plaster said:


> Most likely like cazna said new to it and even tho we must apply pressure there is pushing the tape to hard in leaving no mud on the edge


 Its happened to me as well, Sometimes wipe down with the blade on an angle to the tape so mud comes out one side more than the other and a little bit of the edge gets missed. easy down, Use fuse so you can always see whats going on, No misses then.


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## embella plaster (Sep 21, 2013)

Exactly if fuse does bubble you straight away cut it shrinks to nothing


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## nidaho (Jul 26, 2015)

thanks for the info I will keep after it, even with the few problems I am having the bazooka is well worth, it cant believe I didn't get one sooner.


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## endo_alley (Nov 2, 2013)

nidaho said:


> always been a banjo taper and have switched to a bazooka. I never get bubbles under the tape with the banjo. what am I doing wrong with the bazooka, I got about 5 bubbles on the last house. is it possible that it was caused by a new wipe down knife being to stiff or from not keeping enough pressure on the wall with the bazooka and getting dry spots. it seemed that it was always the edge of the tape not the center. thanks for any info


 Sounds like air in gun. Keep the pump screen clean. A dirty pump screen may allow air in. Make sure there is enough mud in the bucket from which you pump the mud. And some kind of stomper to push mud along side the pump as mud gets lower in bucket. When you advance the tape after a cut, roll the drive wheel along the wall or ceiling to get mud under the next piece of tape.


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## GreatLakesTools (Feb 27, 2015)

nidaho said:


> always been a banjo taper and have switched to a bazooka. I never get bubbles under the tape with the banjo. what am I doing wrong with the bazooka, I got about 5 bubbles on the last house. is it possible that it was caused by a new wipe down knife being to stiff or from not keeping enough pressure on the wall with the bazooka and getting dry spots. it seemed that it was always the edge of the tape not the center. thanks for any info


Are most of them about 5" from the corner?


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## nidaho (Jul 26, 2015)

yes there were some that were 5 to 10 inches from the corner. I also remembering sucking some air when the mud was low, I started mixing 2 buckets at a time so I could keep mud full. by the way those northstar tools are great.


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## GreatLakesTools (Feb 27, 2015)

nidaho said:


> yes there were some that were 5 to 10 inches from the corner. I also remembering sucking some air when the mud was low, I started mixing 2 buckets at a time so I could keep mud full. by the way those northstar tools are great.


When you prime/advance tape out to start each joint by using the drive dog assembly (little "key" you turn with your left hand), you are pushing the back side of the tabs on the large sprocket. (The drive dog pushes the sprocket.)

When you run the tool down the wall, you are pushing the drive dog with the front of the tabs on the large sprocket. (The sprocket pushes the drive dog.) 

The gap between the tabs on the large sprocket leaves a very small "neutral zone" for the drive dog when running the tool down the wall after priming the tape by hand. 

When you prime/advance the first bit of tape by turning the drive dog, you are in a sense leaving the drive dog not engaged with the front of the tabs on the sprocket. The gap between the tabs on the large sprocket, and the weight of the mud on the piston CAN allow the cable drum to reverse slightly. That in turn can allow the piston to "fall back" in the tube, and the mud to settle a very small amount, especially when full or standing upright. (Ceiling corners)

Even if the piston doesn't fall back, it will still take partial rotation of the drive wheel and sprocket to start to move the drive dog, and move the piston.

Either scenario can cause a small dry spot in the tape about 5 or so inches from the corner. The majority of times, it should wipe in or roll in. You can try to avoid this by priming/advancing the tape by rolling the wheel on the wall instead of turning the drive dog. 

Are you using full weight taping mud? Lightweight compound will blister a lot more as it doesn't have the same amount of slip, as well as having less glue.

Hope this helps!


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## nidaho (Jul 26, 2015)

that is exactly what was happening on the corners I was priming by hand to get a tab out, I was also using light taping, it is all they stock in town I will switch to full weight, just have to order it in. I also will start to roll the wheel on the wall to get the tab out. so far that is the only problem I have had with my new set of tools, and learning mud consistency. even with the few problems I am way faster with the tools still trying to get a good rhythm down.


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## GreatLakesTools (Feb 27, 2015)

nidaho said:


> that is exactly what was happening on the corners I was priming by hand to get a tab out, I was also using light taping, it is all they stock in town I will switch to full weight, just have to order it in. I also will start to roll the wheel on the wall to get the tab out. so far that is the only problem I have had with my new set of tools, and learning mud consistency. even with the few problems I am way faster with the tools still trying to get a good rhythm down.


I edited it after you replied.


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## GreatLakesTools (Feb 27, 2015)

You should be fine with full weight. I turn tape out by hand all the time.


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## endo_alley (Nov 2, 2013)

As soon as you cut the tape, advance the next piece of tape. Roll the "taper wheel" for 6 inches or so on the wall, allowing the mud to pop the tape forward no more than an inch or so. Do this in a part of the wall that will be covered with mud during the fill coat, as it leaves wheel tracks. You are now ready to apply a new piece of tape. With this method you will not have a dry spot upon starting a new piece of tape. I do not advance the "drive dog" between cuts by hand, typically. That is too slow, as it requires lowering the bazooka from the wall or ceiling. Now If you are sucking air into the pump and pushing that air into the tube, that is another story.


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## nidaho (Jul 26, 2015)

I went and checked the bazooka out and I found that the brake was not engaged properly, I think when washing it off I must have moved the adjuster for the brake, I was basically free wheeling with no brake, I did not realize the brake adjuster move so easy I will make sure it is working properly from now on. again thanks to all for the info I think I have a lot better understanding on how to use it now


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## GreatLakesTools (Feb 27, 2015)

nidaho said:


> I went and checked the bazooka out and I found that the brake was not engaged properly, I think when washing it off I must have moved the adjuster for the brake, I was basically free wheeling with no brake, I did not realize the brake adjuster move so easy I will make sure it is working properly from now on. again thanks to all for the info I think I have a lot better understanding on how to use it now


That'll do it too.


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## gazman (Apr 29, 2011)

gazman said:


> Most probably user error if you are new to the zooka, trust me I know. Check your brake make sure that it is not rolling backwards, if it is you will get air in the tube.
> When you advance your tape be sure that the wheels are rolling or you will get a dry patch. And as you are taping be sure that the wheels are in constant contact with the board.


:yes::yes:


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## endo_alley (Nov 2, 2013)

Where is the brake? My taper doesn't seem to have one. My box handle has a brake.


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## nidaho (Jul 26, 2015)

not a pro but my brake is just under the wheel it adjusts by moving it back and forth, it is not a brake like on your box handle It is more of a tension adjuster on the wheel not allowing it to roll back wards and putting drag on the wheel. i am sure it varies from brand to brand mine is the north star elite. it is something that first time rookies should not over look (like myself) I am learning and it will well worth it.


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## endo_alley (Nov 2, 2013)

Now I understand what you are talking about. It is what I sometimes call the ratcheting mechanism that only allows the drive wheel to go forward. I think I have seen that called a "pawl" in the Tape Tech parts list. But I could be wrong. Yeah, that little part is pretty important.


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## fr8train (Jan 20, 2008)

nidaho said:


> that is exactly what was happening on the corners I was priming by hand to get a tab out, I was also using light taping, it is all they stock in town I will switch to full weight, just have to order it in. I also will start to roll the wheel on the wall to get the tab out. so far that is the only problem I have had with my new set of tools, and learning mud consistency. even with the few problems I am way faster with the tools still trying to get a good rhythm down.


We had this issue a few years back when we tested a prototype lightweight a/p for Proform. (Was all hush hush at the time, came in unmarked white buckets.)

We noticed the mud had a compression, you would get a dry spot because the mud would compress then start coming out. When you stopped, the mud kept coming. Had it on darn near every joint. Didn't have that problem before, didn't have it after.

Maybe PA Rocker will chime in, he was the one running the taper.


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## fr8train (Jan 20, 2008)

endo_alley said:


> Where is the brake? My taper doesn't seem to have one. My box handle has a brake.


We call it "the clicker", I keep mine set as light as I can get it without it not engaging.


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## mld (Jul 2, 2012)

fr8train said:


> We had this issue a few years back when we tested a prototype lightweight a/p for Proform. (Was all hush hush at the time, came in unmarked white buckets.)
> 
> We noticed the mud had a compression, you would get a dry spot because the mud would compress then start coming out. When you stopped, the mud kept coming. Had it on darn near every joint. Didn't have that problem before, didn't have it after.
> 
> Maybe PA Rocker will chime in, he was the one running the taper.


I would agree with this. I tried some different LW taping muds and had the same thing happen. Switch back to mean green and runs like a dream- a heavy dream!


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