Drywall technique

Jun 05, 2008 9 Replies

I want to try using a sponge to smooth the drywall joints instead of sanding in an effort to reduce the dust generated.



How long should you let the compound dry before using the damp sponge?



TIA



Mike



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It should be completely dry. If the coats aren't too heavy and you've allowed time to dry between coats, 24 hours is normally sufficient.

After mud has set for a couple of hours, I sometimes smooth out edges and ridges with a mudding knife dipped in water. It helps to minimize sanding once mud has dried. Wet sanding is great at keeping dust down. Have also tried the sanding block attachment for the vacuum. Some dust but most of it gets sucked into the vacuum.

Renting a Portercable power drywall sander with a Portercable tool activated Shopvac is an option as well.Gets about 90% of the dust.You only have to hand sand a half inch of the inside corners. We have used them for several years with GREAT results. Wet sanding with a sponge tends to leave area "shiney" looking after painting....Good luck....

A poor technique at best. Use a good shop vac in conjunction with a MagnaSand unit. The outfit comes with a screen type sanding pad that is sucke flat to the wall and makes sanding way easy. The dust is trapped in the MagnaSand water bucket for easy disposal. Some folks with clay type soil put the wet dust on their garden since calcium sulfate (gypsum) is a known clay soil conditioner. Use a spritz of Pam cooking spray to control foaming in the water trap. HTH

Joe

A poor technique at best. Use a good shop vac in conjunction with a MagnaSand unit. The outfit comes with a screen type sanding pad that is sucke flat to the wall and makes sanding way easy. The dust is trapped in the MagnaSand water bucket for easy disposal. Some folks with clay type soil put the wet dust on their garden since calcium sulfate (gypsum) is a known clay soil conditioner. Use a spritz of Pam cooking spray to control foaming in the water trap. HTH

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Better yet, use the knife more carefully so you don't need to sand much. If you put too much on, you have to sand it off.

Sanding with a large sandpaper holder, either with or without a vacuum serves to flatten the mud, making a smooth surface across the sheets of drywall. Unless you have kept the mud buildup to a minimum with no hills or bumps a wet sponge will only smooth out the bumps into gentle hills and not take off any excessive mud, which is needed to get a dead flat appearing joint. The gentle rolling hills will be visible after the first coat of paint.

I get my dear sweet old mudder to do my drywall finishing.

It does work, but even the 220 screen leaves a surface that's too "scratchy" looking to me under critical lighting.

If you buy one, shop locally, because online prices are much higher - and make sure you have hearing protectors rated for aircraft carrier flight decks (no kidding, I have a pair) because that baby really HOWLS!

Absolutely right - so if you sponge, be sure to get something BIG like the ones Lowes & DoItBest hdwe sells:

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and use it in a circular motion like you're washing a wall.

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