Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 20 of 51 Posts

·
Registered
Joined
·
808 Posts
Discussion Starter · #1 ·
This question may have already been addressed in here, but I thought I would ask it anyway. What causes those pesky little air bubbles to come to the surface of my mud? This happens after I smooth the surface out. I get it like I want it then after a few minutes, here they come. If I lightly knock them down again this usually takes care of it.
I'm curious about what causes this and how I can prevent it.
Any thoughts?
rj
 

·
Lack Of All Trades
Joined
·
1,232 Posts
Try to apply it in thinner coats and layers; I believe you are using too much mud for each coat of compound.
 

·
Registered
Joined
·
322 Posts
This question may have already been addressed in here, but I thought I would ask it anyway. What causes those pesky little air bubbles to come to the surface of my mud? This happens after I smooth the surface out. I get it like I want it then after a few minutes, here they come. If I lightly knock them down again this usually takes care of it.
I'm curious about what causes this and how I can prevent it.
Any thoughts?
rj
Those pesky little air bubbles are from "effervasiant" (okay I can't spell) bubbles from the grease and JUNK on the old walls,,, The only way to avoid them is to prime the OLD WALLS ahead of finishing,,, or just deal with em (thats what we do) cause its easier and cheaper than priming everything ahead of time.

Really, its just one of them things that ya have to deal with on re-models. wish I had a magic bullet for ya,, but there ain"t one
 

·
30 yrs carpentry/drywall
Joined
·
89 Posts
The more water you add to the mud - the more "bubbles" you get when applying it (especially when applying thicker coats).

There's a trade off - add more water to run the mud faster with less stress/wear on your arm but deal with more bubbles and having to swipe over the joint/area 1 or 2 extra times to get them to go away

or

add less water to reduce bubbling but put more stress on your arm using thicker mud which causes fatigue faster.

I opt for the thinner mud!

I forgot to mention - there's also another issue to deal with when adding water to your mud. The more you add - the more the mud shrinks as it dries and that causes it to crack. The trick is to not thin it too much when using it for 1st and/or 2nd coats.
 

·
Registered
Joined
·
808 Posts
Discussion Starter · #6 ·
Thanks for the feedback. I was hoping there was something I was doing that prevented or reduced the bubbles. Thinning my mud is a must for me. It sounds like I'll just have continue to live with air bubbles coming to the surface.
I've heard of old-timers putting a shot of dish soap in their mud bucket but I didn't know what that did or what problems that might cause.
rj
 

·
Registered
Joined
·
1,768 Posts
The air bubbles are there cause when mixing the mud air gets trapped in the mud, the more you mix it the more air that gets trapped, try not to mix the mud use it right out of the bucket, unless you have water sitting on top of the mud, then I would give it a slow mix just to get the water mixed in. The brown bag is best used for your bed coat when taping with papere tape or mesh. then if you want to use the white to coat that, but I would use topping compound cause it sands out a lot easier.
 

·
Registered
Joined
·
322 Posts
The air bubbles are there cause when mixing the mud air gets trapped in the mud, the more you mix it the more air that gets trapped, try not to mix the mud use it right out of the bucket, unless you have water sitting on top of the mud, then I would give it a slow mix just to get the water mixed in. The brown bag is best used for your bed coat when taping with papere tape or mesh. then if you want to use the white to coat that, but I would use topping compound cause it sands out a lot easier.
Frank, he ain't talking about "air bubbles in the mud" (pock marks, or pinholes)he's talking about the little bubbles that come up in a remodel, after you run your mud,,, ya know coming from the junk on the wall, due to the reaction from new mud on old walls
 

·
Registered
Joined
·
6 Posts
we call them pocks or pimples lol.when i coat i dont like adding to much water to my mud cause it can cause the mud to shrinks to much.then you can get humps in your cross seams or the the flats could cup.
try useing light weight usg.the blue lid(for coat only).no water just a little hand soap and mix.
 

·
Registered
Joined
·
108 Posts
Pin holes in mud

The only time I've had that happen is when blending new and old sheet rock. Spoke to a USG rep and he said, as it dries the mosture can't soak into the old sealed area of drywall. So it comes out the other way "To the surface". If you are getting that with brand new work your not mixing or applying to thick of a coat.
 

·
Registered
Joined
·
843 Posts
If USG and the other major mud manufacturers wouldn't add so much air to the mud to gain volume to fill the bucket, we wouldn't have nearly the problem with the bubbles. Lite mud is the worst for this problem. Plus 3...
I noticed in using some of the "lesser" brands, the problem is not as bad. And mostly not there at all.:whistling
 

·
Registered
Joined
·
100 Posts
If USG and the other major mud manufacturers wouldn't add so much air to the mud to gain volume to fill the bucket, we wouldn't have nearly the problem with the bubbles. Lite mud is the worst for this problem. Plus 3...
I noticed in using some of the "lesser" brands, the problem is not as bad. And mostly not there at all.:whistling
Have you ever weighed the same size containers of mud from different manufacturers?
 

·
Banned
Joined
·
215 Posts
just make sure to mix the soft top well and apply a thinner coat, their usually gone by the time I have to sand.

They are just air that develop from mixing as someone pointed out, as long as it's just air in the bubble and not unmixed powder.
I rarely get them when i mix by hand, mostly when I use the electric mixer.
 

·
Registered
Joined
·
5 Posts
Hi rj,
sometimes i'll get air bubbles if i try to apply a second coat before my first coat is fully cured....like some of the responces said....you can wait till it's fully dried and you knock the heads off with a broad knife/6" knife, give a lite sand with 100 grit sand paper and touch up with some redi-mix and you'll be good to go! Good luck my friend.

Blaise
 

·
Grand Rapids Remodeling
Joined
·
3,115 Posts
The Capt. got it right. Going over dirty old paint will always produce air bubbles. Kinda like bubbles in a glass of beer, the more bubbles the more left over soap and dirt are in the glass. Not that I would know anything about drinking beer. :shutup:

I also use the dawn but the jury's still out on how effective it is. It's does make the mud smell nice though.
 
1 - 20 of 51 Posts
Top