Repairing bad mud jobs?


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Old 02-04-17, 11:41 PM
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Repairing bad mud jobs?

Hi.

I did my first ever spackling a couple years ago when I first moved into this 1971 small ranch as there were many fits size holes and dings in the walls. I think the guy was angry with the foreclosure and made holes in the walls or was just a guy with a temper cause there were also a couple holes behind door knobs where the doors hit the wall.

Anyways, my brother in law helped spackle when we first moved in a did a "quick job" and left many areas that are raised that you can especially see when the light hits it, etc.

I myself didn't really know much about sanding properly and I think I did almost the same in some areas.

I realized a while ago that once the paint dries, etc it becomes harder to sand down the "mistakes" or areas that I didn't sand so flush.

Is there a "standard" technique or do you just use a sanding block and/or scraper and start scraping/sanding away at the area to get it smoother? These areas have all been painted over.
 
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Old 02-05-17, 02:48 AM
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Here is a selection of tools. I like the pole sanders best. Be ready with a lot of sand paper as paint will fill up paper fast.
 
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Old 02-05-17, 03:10 AM
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For a quick sanding use a random orbit sander. Just another excuse to buy tools, but it works.
 
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Old 02-05-17, 04:00 AM
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Joint compound that has been coated with latex paint doesn't sand very well, the paint will 'melt' and plug the sandpaper in short order. Sometimes it's better to float the mud out over a larger area to make the hump appear to disappear.
 
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Old 02-05-17, 05:59 AM
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First, DO NOT USE POWER TOOLS TO SAND DRYWALL!!

You will end up with a much larger mess than you currently have.

You are correct, once painted the paint soaks into the patched area and dries, you need to get past that to begin the repair.

First, try the sanding screens they are designed for drywall, have a large flat area and tend to not dig into the wall/repair area.

6" drywall knife, topper compound, multiple thin coats, light sanding and 2 coats of good PVA primer with a roller (small 4" pink rollers) to add texture to the patch feathered out well past the repair.
 
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Old 02-05-17, 06:05 AM
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I'll have to draw a line on not using power tools, as blanket advice such as that is improper. If properly used, they can help do a faster and smoother job. If you are a hack, yes, stay away from anything with power, or anything sharp.
 
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Old 02-05-17, 06:11 AM
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When sanding latex paint, the heat generated 'melts' the paint plugging up the paper. Power sanding intensifies that effect ..... although there isn't much harm in giving the wall a once over with an electric sander.
 
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Old 02-05-17, 06:29 AM
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I have used sanding screen on my ROS with fine results. Sure the paint clogs it up, but once it gets down to the mud, not so much clogging. Plus the vacuum action of the ROS helps to keep the clogging to a minimum.
 
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Old 02-05-17, 07:49 AM
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Another vote for the random orbital sander, ok if you are careful. The danger is sanding into the paper around the patch and that area doesn't need to be sanded. Lay a straight edge across the patch to see how high it is and only sand the high areas. On a really botched job I once actually used a paint scraper to gouge out some of the old mud, gouges are easy to fill in.

As Marq1 said, multiple thin coats feathered out to the sides. A baseball size hole should end up with a basketball size patch (or larger) with virtually no bump in the center.

Bud
 
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Old 02-05-17, 11:01 AM
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I myself didn't really know much about sanding properly
I think we should let him start out hand sanding before we encourage power tools.

On a personal note, I have never nor would I ever use any kind of power sander on drywall and I'm all in on having any and all tools known to mankind!
 
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Old 02-05-17, 11:13 AM
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You will until you have your shoulders replaced. Then any power tool that will help keep you from swinging your arm sanding will be a Godsend. That's why I do it.
 
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Old 02-05-17, 01:26 PM
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On a personal note, I have never nor would I ever use any kind of power sander on drywall and I'm all in on having any and all tools known to mankind!
Obviously you have not used/seen a Porter Cable Drywall sander. I have one and it is a wonderful tool for sanding drywall. I got mine used for about $200 as they are about $800 new with the vacuum.
 
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Old 02-06-17, 08:41 PM
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How about scraping at it first with a scraper and then once most of paint is off just sanding?
 
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Old 02-07-17, 02:37 AM
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It doesn't hurt to scrape off the high spots.
 
 

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