Air bubbles in Dry wall mud

admin

Just for the sake of conversation..... I'm fixing up the laundry room,  New drywall, and all.   Plumping copper pipe is almost like welding..... Isn't it?    So I'm happy to say, that after a bunch of re-fits, and moving some pipe around, not a single joint leaked when the water was turned back on.  And I usually hate redoing old plumbing.  Anyway, my question.....    After applying the dry wall and the first coat of mud, (plaster).  I then applied the second and third coats.  Looked pretty good until I started to sand the ridges out.  After removing a thin top layer, little pin holes started to show up, which indicate air bubbles in the mud.  Does anyone know how to stop this from happening?  I have always had a problem with these bubbles, and am starting to get a little frustrated with it.  What am I doing wrong?  Is it mud prep?  Or is it mud quality?  I'm just using a Home Hardware brand.  General purpose mud.  Any thoughts or feedback would be welcome.  Or if anyone knows a professional dry waller...... Thanks  PackratLincoln 225 AC/DC, Hobart 140 Mig. Oxy/propane Victor torch.(2) Makita 5" angle grinders  one with zip disk, 14" chop saw.  and just about every other tool you can think of. Whoever has the most toys when he die's ..... Wins!
Reply:I'd say you need to work the mud a little more before you apply it.  Kinda like kneading bread... good luck,jumper
Reply:Air bubbles are common in cheaper mud. Some brands you just can't get rid of them at all. That's why you point up after priming the walls. We have an in house brand here that is just garbage.A good thin skim coat will take care of them in the block ( 2nd) coat. If you are using a drill to mix, don't let the paddle get any air to it. If it does, bubbles are gauranteed. Mixing a little thin, esp with skim coat mud, will help with bubbles. If you thin out the tape and block mud, you can develop shrinkage issues.Bottom line is this. Mud quality and overmixing are the two biggies. You'll just have to experiment to find the best combo for what you have.
Reply:What is "point up" after priming?  How do you mix without getting air into the paddle?  Run the drill slower?   Your probably right about the mud quality.  It is the cheap brand.  I don't think I mixed my 3rd coat thin enough either.  But like you said, if it's too thin, then you have shrinkage.  Mudding is not my most favorite job.  Out of all the reno work I do, this is the one I run out of patience with really fast.  I've gotten a lot better at it over the years, but still would rather do other stuff than mud.  I seem to always be doing it, so went out and spent the money on some good quality tools for the job.  That has helped a lot.  I usually fix the bubbles too, but it requires that fourth coat, and more messing around.  I think for my next mudding job I will buy the better quality mud.  PackratLincoln 225 AC/DC, Hobart 140 Mig. Oxy/propane Victor torch.(2) Makita 5" angle grinders  one with zip disk, 14" chop saw.  and just about every other tool you can think of. Whoever has the most toys when he die's ..... Wins!
Reply:Point up is when you go in after the prime coat ( paint) and spot apply mud to all the imperfections. We did millions of square feet of slick walls in Wash DC area. They wanted a slick, no imperfection wall surface. Point up was the only way. One job took three point up sessions. Pain in the butt, but it was necessary.Mixing is a tougher ques. I always made sure the bucket had plenty in it. When the mud starts spinning, just make sure the paddle doesn't see air. If it does, you get air entrapment. If you need just a small amount, mix by hand.   I don't know what you have available, but any USG mud will be fine. I use the regular ( green box) for tape and block coats and like the Plus Three mix ( blue box ) for skim and point up. It seems to be way smoother, but it will cost more.
Reply:We have some better quality stuff here, But it is, more expensive.  It comes in three different textures.  Yellow box is for your first coat, Blue box for the second, and green is a fine finish coat.   I can't remember the brand name right now.  But I have used it in the past, with good results.  I was just to cheap this time to spend the extra money for just one room.  They only come in 20kg boxes.  I don't need that much mud.  I did do the "Point up" but not exactly the same way,  I did it before primer, instead of after.   My wife is very fussy and always wants the walls to look perfect.  In a way that's a good thing...... I use to do everything with the attitude.... ahhh that's close enough for government work.  Thanks for the tips.  I'll put them to good use on the next mudding job. PackratLincoln 225 AC/DC, Hobart 140 Mig. Oxy/propane Victor torch.(2) Makita 5" angle grinders  one with zip disk, 14" chop saw.  and just about every other tool you can think of. Whoever has the most toys when he die's ..... Wins!
Reply:I've had good luck using a wet scotch brite pad when those little bubbles show up. It kind of sands the high spots and deposits in the low spots. I know this is half assed, but it worked for the restoration contractor that employed me.
Reply:Originally Posted by gimpyrobbI've had good luck using a wet scotch brite pad when those little bubbles show up. It kind of sands the high spots and deposits in the low spots. I know this is half assed, but it worked for the restoration contractor that employed me.
Reply:Dish washing liquid. You read that right. I work on summer on a big commercial job and kept seeing these cheap dollar a bottle yellow dish washing liquid bottles all over the place. Then one day i seen what the deal was. The sheet-rockers were mixing it in the mud with a drill paddle. I asked what the deal was and was told it made it spread a lot smoother and kept the air bubbles down. Sorry,I can not remember the brand name they were using.