# First attempt at skim coating



## postwick (Oct 4, 2014)

The wall wasn't in terrible shape to start with, I just wanted a fresh smooth surface to prime and paint. I sanded the wall first. Used the ultralight joint compound (light green lid) and added a little water then mixed with my drill (which started smoking LOL) and one of those mixer attachments.

Should I have left more joint compound on the wall, a thicker layer?

https://flic.kr/p/pug4eT

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## ToolSeeker (Sep 19, 2012)

From the pic should have left more on. But is it smooth or will a light sanding make it smooth ? If so then it's OK


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## postwick (Oct 4, 2014)

Frustrating. Every video I see of people doing it, it leaves a layer of compound on the wall and you can't see the paint through it. Every time I do it, when I scrape, 99% of the compound just scrapes right back off the wall. What am I doing wrong?

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## postwick (Oct 4, 2014)

It's a smooth wall. It was painted with semi gloss which I sanded with my palm sander before trying to skim coat. Maybe my expectations for what it should look like are incorrect.

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## Gymschu (Dec 12, 2010)

When you skim, well, that's actually what you do, you skim over the mud. If it's the right consistency (like pancake batter) when you trowel over the mud you basically just smooth it down with your trowel or a 6" taping knife. They also make a plastic type trowel that works decent enough. Any type of SCRAPING is wrong because it takes off too much mud. As Toolseeker said, the pic shows that you took way too much off the wall. Plus, you need to adjust the consistency of your mud. It takes more than "a little water" to get it to be like pancake batter.

I usually get an empty 5 gallon bucket and put about 1/3 of the bucket of mud into the empty fiver. Then I add water and start mixing. Add in a little at a time until you get that pancake batter consistency. This method is easier on your drill.

Also, most skim jobs require TWO coats anyway to properly smooth out any low spots, etc.


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## jeffnc (Apr 1, 2011)

I will disagree a little with previous advice. I don't necessarily think you took too much off.

First, the compound should be thin enough to apply with a paint roller, as if it were thick paint. Why? Well, one reason is that you actually should apply it with a paint roller.

Second, I don't think a metal knife is the best tool for this. I think a squeegee is best.
http://www.texmaster.com/magictrowel.html

Now if you really thin out the compound, then it's not going to be real thick on the wall. As long as your wall is smooth when done, then you've used enough compound IMO. Any more and you're simply making your walls heavier for no good reason. For sure you're going to want to prime (seal) afterward, and then lightly sand after that, so your walls will be smooth, assuming you patched any larger gouges before starting.


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## jeffnc (Apr 1, 2011)

postwick said:


> It's a smooth wall. It was painted with semi gloss which I sanded with my palm sander before trying to skim coat.


I think at that point, you barely had a need for skim coating, and that's the main reason you're getting such a thin coat, which is fine.


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## postwick (Oct 4, 2014)

Thanks everyone. Being a small wall in a room I have to do first (see the spot where the pedestal sink was pressed into the plaster) this was a practice run for doing my living room where the walls are in worse shape.

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## scottktmrider (Jul 1, 2012)

Better to have it too thin than too thick on the wall. you can allways go over it again


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## ToolSeeker (Sep 19, 2012)

Not trying to start an argument but I have tried the paint roller method. Went out and bought magic trowel which is a squeegee. I never got it to work where I was happy with the results so I went back to my metal trowel. I also read Myron's article. 

The problems were, hard to roll, wants to slide, a lot ends up on the floor. Can only do 3 passes then have to squeegee or it will start drying on you then hard to remove. Have to keep adding water and re-stirring the bucket as what you are putting back in will dry it out. And squeegee tends to leave uneven areas, thicker in spots.

It was really one of those things you want to work, skimming is hard. And you need as big a knife as you can handle, at least a 12". And from the pic it looks like your holding your knife at too steep an angle.


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## postwick (Oct 4, 2014)

By too steep do you mean too close to 90 degrees from the wall or too close to parallel with the wall?

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## postwick (Oct 4, 2014)

Oh and is it generally easier with a trowel than a taping knife? I used a 12" taping knife.

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## jeffnc (Apr 1, 2011)

Actually, I first read about the paint roller from Ferguson for the 3rd coat of normal drywall finishing (i.e. Level 4 finish). It can slide, but once I got the consistency right it worked well for me.


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## ToolSeeker (Sep 19, 2012)

Too close to 90 and trowel or knife is an age old question I prefer trowels for skimming but a lot of guys use knifes and 12 should be big enough.


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## jeffnc (Apr 1, 2011)

postwick said:


> Oh and is it generally easier with a trowel than a taping knife? I used a 12" taping knife.


It's probably personal preference. I think the main thing is the width of the blade. Knives are typically available up to 14", trowels up to 16", and squeegees up to 22", which is another reason I like the squeegee  When you're doing a joint, you don't need anything over 12", but when you're doing the entire wall, the larger size really helps.

(Actually when doing a patch, having a tool that can span the whole patch is a big help in getting a flat surface. If your patch is 16" wide from middle of tape joint to middle of tape joint, then having a tool that's at least 16" wide helps span the whole thing. I've actually used a level before to get a wider surface.)


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## postwick (Oct 4, 2014)

Thanks for the advice, everyone. Adding more water gave me that pancake batter consistency, and the 12" knife worked kind of ok but I think I'll get a trowel for doing the larger walls in the living room. 

And here's my tip for the day. Don't let the mixer attachment touch the sides of the bucket. Picking all the orange plastic shavings out of the mud on the wall was a little tedious 😖

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## jeffnc (Apr 1, 2011)

postwick said:


> Don't let the mixer attachment touch the sides of the bucket. Picking all the orange plastic shavings out of the mud on the wall was a little tedious


Yikes, I have to admit, it's the first time I've heard that one.....


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## Gymschu (Dec 12, 2010)

As a newbie at skim coating, a 6 inch blade may work much better. A 12 inch blade can be a challenge to control sometimes and if the wall is really wavy with high and low spots, you can end up gouging into the mud on the high parts and leaving valleys where the low spots are.


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## jeffnc (Apr 1, 2011)

I hear ya. But that's one reason I like the squeegee - helps with that


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## diyplaster (Nov 12, 2014)

*Skimming Bathroom*

I would call what you did a 'tight skim'. 

If all you have to level out is the 'orange peel' built up from roller texture, a tight skim is all you really need. 

The angle of the knife or trowel does effect how much material you leave on the wall. As you get more parallel to the wall, more material is left on. As the knife becomes more perpendicular to the wall, the less material is left on. 

In this case, less material is likely ok, esp. since you sanded the surface before skimming. 

I would recommend priming with oil based kilz before skimming however. Sometimes there can be a bonding issue with the material you are putting on and the painted surface, especially if it is oil or has a sheen. 

And the material you used....my preference is the powder form of the 'setting type' joint compound. Used to be called Dura-bond. Lightweight is fine. It is more resistant to moisture damage, esp. in a bathroom. 

After skimming, sand lightly with 120 grit. Prime with PVA primer and topcoat with paint of choice, but I would choose one with a sheen, as it is more resistant to moisture. 

Good luck !


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## jeffnc (Apr 1, 2011)

diyplaster said:


> And the material you used....my preference is the powder form of the 'setting type' joint compound. Used to be called Dura-bond. Lightweight is fine.


Powder form is the only form of setting compound!  Durabond still exists, but not only is lightweight setting compound fine, it's the only one I would use. Any setting compound is going to be harder than any drying compound. The problem is sanding though - Durabond is like iron, and you won't be able to sand it level with any other joint comound on the wall. The sander will take off the other compound, and leave the Durabond, making it all but impossible to get things really flat. Overally, agree with your post.


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## ToolSeeker (Sep 19, 2012)

I would personally not recommend either for a diy project like this. Setting compounds are hard to work with if you know what your doing. Now combine that with little or no knife/trowel experience, little or no experience mixing or working with setting compounds, and a large room to do. And I see how things could go real bad real quick, like in the time it takes for the first batch to set up.


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## jeffnc (Apr 1, 2011)

Agree with that advice ^


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## diyplaster (Nov 12, 2014)

Thanks for the input Jeffnc. I was trying to be excruciatingly clear about which product I was referring to. 

The material I suggested used to just be called 'Durabond' (as you may know), but the descriptive name was changed to 'setting type' joint compound, as opposed to the very similarly named but premixed 'joint compound'. 

I regularly use the setting type (lightweight) for my first passes, and only use 'bucket mud' or premixed joint compound for a final skim, because it is so sand-able. 

There are good uses for the old Durabond as well, but we can't readily get it here in Greensboro. 

Both setting types can be finished with a trowel and water, creating a finish much more like true plaster, and I have used it that way on more than one occasion.


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## diyplaster (Nov 12, 2014)

Depending on how deeply the material had to be applied would determine when to use which one. 

From the one photo I saw just now, it is likely that bucket mud would be all that was needed and certainly be a lot easier for an untrained hand to work with. So, I agree with ToolSeeker in his advice.


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## jeffnc (Apr 1, 2011)

diyplaster said:


> The material I suggested used to just be called 'Durabond' (as you may know), but the descriptive name was changed to 'setting type' joint compound, as opposed to the very similarly named but premixed 'joint compound'.


A little confused by what you mean, because they sell this
http://www.usg.com/content/usgcom/e...ckbranddurabondsettingtypejointcompounds.html

And this
http://www.usg.com/content/usgcom/e...sandlightweightsettingtypejointcompounds.html

which is both "easy sand" and "lightweight". Both those terms are relative to Durabond, I assume. Obviously this is different from this, which is also confusingly called "lightweight", available in both a drying-type powder mix, and premixed.
http://www.usg.com/content/usgcom/e...dplus3lightweightallpurposejointcompound.html




diyplaster said:


> I regularly use the setting type (lightweight) for my first passes, and only use 'bucket mud' or premixed joint compound for a final skim, because it is so sand-able.


I often do that as well. It's the only way I know to do a drywall patch in 2 days. Day 1, first 2 coats of setting compound, and third coat of premixed. Day 2, hopefully that is dry and can be sanded and then primed/painted. If a little more premixed is needed to touch up, I bring out my handy little hairdryer


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## ToolSeeker (Sep 19, 2012)

Dura bond is usually the almost unsandable in the brown bag. The white bag is usually known as EZ sand (which I find misleading) I guess because it's easier than the brown bag. We used to call all of it Dura Bond and would refer to the bag color but that seems to have changed over time.


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## oldrivers (May 2, 2009)

To get the best results apply mud with a 12 inch trowel then go over it with a 20 inch trowel, 2 coats depending on the condition of the wall . 

a good set of trowels will cost 80 or so , cant be beat .


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## diyplaster (Nov 12, 2014)

jeffnc said:


> A little confused by what you mean, because they sell this
> http://www.usg.com/content/usgcom/e...ckbranddurabondsettingtypejointcompounds.html
> 
> And this
> ...


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