I just did a small drywall repair and the instructions on the container said to use a wet sponge to smooth and finish after the compound dried. I have used wet sandpaper in the past but other than that just used regular dry sandpaper to smooth. Is this wet sponging something new. Are there special sponges for this? I like the idea of less/no dust.
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Jim
I use a drywall sanding screen on a hand drywall sander. Wet but not dripping. Dip in bucket, wipe off with hand and have at it in a circular pattern.
Don't stay in one place too long, too wet and you'll smear the once dry topping too much.
clean off the screen often, no need to remove from sander.
I've also used a not coarse rag (t-shirt) or grout sponge, but it can drag lines in the patch.
when patching on roll coat, dob texture or stipple finish I'll use a wet rag or sponge to blend the edge of patch in to remove the hard edge of the patch. Then, when dry I apply the matching texture to make it disappear. Run out the matching texture lightly beyond the patch to blend in.
no idea if there's a special sponge.
Calvin
I saw a reference to an orange sponge. Wonder if one of those kitchen scrubber sponges, pot scrubber on one side and regular sponge on the other, will do the job. Do you sponge between coats or just after the last coat has been applied and dried?
Jim
I never sand or sponge between coats. I do knock off hitchhikers with a knife as necessary.
the sanding screen on the drywall hand sander I've found for me to be the best bet for wet sanding if necessary.
I use the wet sand if a small patch and no desire for any dust whatsoever, or walls in stores when changing out displays. It's more time consuming.
I've never tried it personally, but the technique has been around 15-20 years, and it was all the rage for awhile. Especially recommended for DIYers who have trouble getting a smooth coat.
A technique I use is, after the mud is set, take a wide broadknife and scrape. Unlike sanding, this knocks off the high spots without taking anything off the low spots, and it makes less of a mess. And (especially) it can be effectively used on the first coat, making the first coat less "fussy".
tape and mud as usual...
Tape, mud, sand as usual.
Prior to priming, wipe the wall down with a wrung-out orange grout sponge to remove any leftover dust. It'll smooth out any marks and give a perfect feathered edge from mud-to-paper. Some areas you wipe lightly, others you can bear down. It'll make sense as you go along.
The mud, I may put a little effort in to if there are mesh scratches that need to be smoothed out. The paper gets a light wiping.
Careful at the mud/paper transitions. If you scrub on the paper too hard you can pill it.
Sponge float.
Use a sponge float. This is not a rubber grout float but a sponge. It has a handle and solid backing so that it will stay flat against the wall.
No panacea
Many patches and repairs are made using setting type drywall compounds; 45 min., 20, or even 5 min. variations. Its quicker...and stronger. The idea is to get in and get out. Waiting for non setting mud to dry between coats is not a very effecient use of time. And wet sponging setting compounds isn't going to feather any of this material once it chemically reacts and sets. While some people like to try it, sponge finishing drywall compound (smooth) is not a regular professional technique and is not going to give you a very flat surface. It might feel smooth, but it won't be flat. Its limited use as a technique for feathering edges (usually DIY applications) can be achieved professionally by properly applying the final skim coat. Thus, there are no special sponges that are marketed specifically for finishing drywall. Even that sponge float shown is not specifically meant for finishing drywall.
We all like the idea of less dust when it comes to drywall finishing. The best way to avoid it is to not have excess mud applied in the first place. Unfortunately (or fortunately;depending on how you look at it) this takes lots of skill which often takes years to perfect.
Deadnuts
Thank You (once again) for your detailed explanation. Just out of curiosity, when the setting compounds are used what is the next step? Are they easily sandable or are they skimmed with a thin finish or are they (hopefully) in a finished state once dried?
Jim
setting powders come in two forms, the original hard Durabond and the sandable and able to sponge no problem, Easysand. All are "timed" so you can do quicker recoats. Quality finishes flat, quick and professional.
As with all drywall work both new and repair......proper finishing techniques produce a quality job. As with most things, some can do it and some can't.
best of luck
can skim with regular mud
We usually skim the setting compounds (usually Easy Sand by USG) with regular drywall compound. This is because I find regular mud seems to feather the best and is actually the "easist" to sand. However, we sometimes skim with setting; both will work.
Skimming is a matter of putting thinned compoound on...and then taking it "all" off. There are some pretty good videos out there that will show you how to properly apply a skim coat. It is usually achieved with a 12" wide drywall knife. This will give you the flattest surface requiring minimal sanding. Regualr mud skim coats dry very quickly. If we are looking to speed the process up, then we use a heat gun or forced air space heater to dehydrate the whole patch area so that we can paint right away. We can usually walk away from a sizeable (and invisiable) patch job with a painted surface in about an hour.
Coincidentally, the Easy Sand compound is now easier to mix than ever. I don't know what they did to change the chemical composition recently, but It seems to me that it practically hydrates itself with very little mixing. It's fantastic to work with. Durabond; not so much.
can skim with regular mud
We usually skim the setting compounds (usually Easy Sand by USG) with regular drywall compound. This is because I find regular mud seems to feather the best and is actually the "easist" to sand. However, we sometimes skim with setting; both will work.
Skimming is a matter of putting thinned compoound on...and then taking it "all" off. There are some pretty good videos out there that will show you how to properly apply a skim coat. It is usually achieved with a 12" wide drywall knife. This will give you the flattest surface requiring minimal sanding. Regualr mud skim coats dry very quickly. If we are looking to speed the process up, then we use a heat gun or forced air space heater to dehydrate the whole patch area so that we can paint right away. We can usually walk away from a sizeable (and invisiable) patch job with a painted surface in about an hour.
Coincidentally, the Easy Sand compound is now easier to mix than ever. I don't know what they did to change the chemical composition recently, but It seems to me that it practically hydrates itself with very little mixing. It's fantastic to work with. Durabond; not so much.
Try it, You'll like it!
"Sanding" with a damp sponge is a long used technique. Note that I said 'damp,' as opposed to 'wet.' The moisture both dissolves the mud and carries it away.
Advantage: No dust
Disadvantage: Doesn't work on hard-setting joint compounds.
You want a firm synthetic sponge with large pores - like the one used to wash cars.
I found a Wet Sanding Sponge in my local hardware store....made in USA by STANLEY. With all the different recommendations I wasn't sure what to buy and as the choices were limited I decided to give this one a shot. It's a good size and has the sponge on one side and a scrubber type pad on the other. As all have said not using a setting compound makes for a fairly long process.