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Hi there, I am about 2/3 of the way through mudding all my drywall and have found several areas where small bubbles, or inclusions are formed after the drywall mud has dried. Is my mix to thick? I have heard of thinning the mix with water to make a thinner mixture. I also heard of adding liquid soap to the mix. Do any of you know if there is any truth to these or is it something im my technique that I need to fix? These bubbles don't appear all the time. Any help would be appreciated. Thanks in advance, John
 

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Probably your technique. You need to do 3-4 thin layers, spread on in increasing widths (up to maybe a foot wide or more) to cover the joints or nail/screw holes. Put on a thickish layer then go back over and feather it out more thinly to the edges by sorta holding the outer edge of the knife tighter to the drywall than you hold the inner edge, and the knife at maybe a 45 deg angle. It takes more time but saves lots of sanding. Don't goop it on, just do it like you are buttering bread evenly with a thin layer. This will prevent a "speedbump" look after it is all done.


I use a 6" knife for all my jointing, and hold the joint compound on a 12" knife. Then get a little gob (like golf ball size or maybe a little bigger) in the center of the 6" knife (it spreads to the edges as you spread it on the wall) off the 12" knife. Spread it then clean the 6" knife back onto the 12" and then re-gob it. This makes the whole job cleaner and easier.


This is harder to explain than to show.


When you are ready to sand buy a sander thing that hooks up to your shop vac. Some suck through a bucket of water to capture the dust and save your vac filter. This will make your job hugely more pleasant, and save lots of domestic tranquility as dust won't be everywhere (and it will be otherwise).


Have fun!
 

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RT, don't crush that dwarf, hand me the pliers!


Hydra, when I mud, I work the compound for a minute or so before I start applying it. haven't you noticed that it becomes "creamier" after a while? I mash the fresh-out-of-the-bucket compound against the side of the bread-pan several times before use.


This softens the mud and makes it more spreadable, and eliminates the tiny bubbles you're talking about. I use the newer 'lightweight' compound, and never add anything. Some people prefer the original, but I've gotten used to the new stuff.


Most important is to never allow dried flakes and chunks to re-enter the bucket. When I take mud from the bucket, I scrape the sides fully clean and flatten the surface, and replace the plastic circle on the mud. When I'm done for the day, I do this extra-carefully.


Then, every so often, work the mud in your pan to keep it all moist and mixed for better consistancy. This helps eliminate those same dry chunks that create those annoying grooves when you drag the taping knife over a joint.


You should expect to use more than one coat when you mud. Butt joints need to be extra-wide; you can't reduce the height, but you can reduce the angle of the slope. Like a speed bump; if you can't lower it, widen it. Tapered joints can be the width of the two mating tapers.


You can almost eliminate butt joints if you lay the walls horizontally, and use 10- and 12-foot sheets when you can. Drywall should always be hung perpendicularly to the framing. If it helps to eliminate ceiling butt joints, use furring strips across the joists to change directions.


Wall butt joints can be hidden above and below windows, and above doors, where the bulges that distort the trim can't be seen. When mudding, I do inside corners with the one-side-per-day method. Mudding always takes more than one application, but you should only need to sand once.


As for sanding, your local tool-renting HD store has the Porter-Cable sanding system, which consists of a motorized, flex-head sander and matching auto-trigger vacuum, with 2-stage filtering. The bag is optional; I use it for cleaner emptying.


When sanding, never sand drywall to the point of roughening the paper. It's better to add more compound and spread the bump out than to try to lower high-spots of drywall. I've ended up making a 1-foot-square patch over 2 feet in each direction, but you'd never find it. It's the speed-bump thing again.
 

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If you use an electric drill and a paddle to mix a bucket be sure to use a slow speed as you can actually entrain tiny air pockets into the mud. Sometimes I will get a bucket that is like this from the store. The problem can be localized in the bucket as well. You should remix every bucket you buy. No added water is needed. You will see a 10 fold increase in the workability of remixed mud. Just do it at 300 to 800 rpms. Most household electric drills are 1200 rpm or more. If you try to use the variable speed to slow it down enough you will burn out the drill. We have an old sears 1/2 inch drill that turns 600 rpms at full blast. It is used for nothing but mud mixing. Here is a tip I learned from watching some union laborers (who mix mud all day) Stand on the rim of the bucket while mixing and it will stay put. Dont slip though !!!
 

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Like Larry said knead/mix the mud on your drywall "hawk" until it has uniform consistency. I only add water sparingly for the final coat. And If you are not in a rush multiple thin coats helps minimize the sanding. Actually I'll sponge and sand very little.
 
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