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enduring

Help with Skim Coat Options?

enduring
11 years ago

I have dry walled my bathroom and have finished the seams. I have primed the whole room with Gardz in preparation to do a skim coat. My ceiling is old stable plaster with some paint still intact and areas of bare plaster where I peeled paint off. The walls are new drywall. There will be a tub in the room but no shower other than a hand held spray at the tub filler. I will surround the tub with Hardibacker and use Hydroban to prep for tile around the alcove tub. There is now an exhaust fan installed.

Now the next step. I would like to skim coat to even out the stabilized peeling paint edges on my plaster ceiling. Also smooth out the wall surface of the mixed textures of joint compound, and drywall paper. After the planned skim coat, I would go over the skim coat with Gardz, to protect the new skim coat, and prep for paint. I was going to use the pre wetted drying type joint compound, thinned a bit with water, rolled on and then knifed smooth. This is one technique that the US Gypsum site demonstrates in a video, for a level 5 finish.

I have read that sometimes the drying type joint compound softens in moist areas like a bathroom. I have read that sometimes people recommend setting type compounds like Easy Sand to skim coat. I know the skim coat is VERY thin and maybe my concerns are unnecessary. But here goes.

My concerns:

1) Bathroom moisture causing the drying type joint compound to soften, causing paint to blister.

2) Easy Sand, if used instead, producing a surface that is not smooth.

3) Will either skim coat method stay adhered to the surface as prepped? - out lined above.

4) Will paint maintain its integrity with either of these surfaces.

What are your thoughts and recommendations?

Thanks.

Comments (13)

  • enduring
    Original Author
    11 years ago

    Sorry about double posting but I thought my other post disappeared since I couldn't find it even after refreshing multiple times over 10 minutes.

    Post replies on other post with title:
    Xpost in Baths, Can I Skim Coat New Bathroom Drywall and Plaster?

  • harry_wild
    11 years ago

    It kind of sound like you do not know what you are doing. I would if I were you; try to get a 12" blade and try to buy a pal of pre-mixed blue joint compound and see if you have the skills to spread it out evenly. If that works then I would do the ceiling and then lightly sand it with a sanding pole. Prime it with KillZ or similar product and paint the ceiling.

    Regarding the wall; I would try to remove all the wallpaper before you apply a skim coat! You can remove wallpaper either with steamer or a spray bottle of dish soap and water and a scraper.

    If you cannot do this; get a drywall contractor to do it! They do this on a daily basis and will do a great job!

  • brickeyee
    11 years ago

    Avod the premix, especially in a bathroom.

    Use Easysand setting compound.
    Mix it with te least waTer you can to get a SMOOTH WORKABLE MIXTURE.

    A drywall knife Of any size is also not the correct tool for skim coating (no wonder the drywall guys have so much trouble skim coating).

    Get a plasterer's trowel, preferable one with about a 1.5 inch round handle (the less than inch ones are very hard to control).
    The one place a 6 inch drywall knife might be handy is to scoop a blob of mixed mud onto the wall from a tray or bucket.

  • enduring
    Original Author
    11 years ago

    Brickeyee, I like your instructions. Is it ok if I go over the thin transparent coating of premixed stuff I put on last night? The reason it is so thin is because when I scraped it off it all came off, except for a thin haze. I think it filled the texture of the Gardz primer. Do I need to re-prime before I add the setting type JC? Thanks.

  • brickeyee
    11 years ago

    You do not need to re-prime, and it is a good thing you only used a thin layer.

    The primer was to reduce water movement into the substrate from the pre-mix.
    Setting has far less water so it can be applied without a barrier.

    Pre-mix is softened by ANY water that gets to it down the line.
    Setting compound does not soften or dissolve if it gets wet.

  • enduring
    Original Author
    11 years ago

    Thanks Brickeyee, I'll be trying this out at the end of the week.

  • brickeyee
    11 years ago

    It takes a little practice to get the hang of the plasterer's trowel.

    You have to raise the edge very slightly in the direction you are moving it.
    That is one reason the larger diameter handle is easier to use.
    A small handle makes it hard to exert force and rotate the blade slightly at the same time.

    Sometimes a masons tool for concrete is easier to find and has a better handle.

  • enduring
    Original Author
    11 years ago

    Brickeyee, The pool trowel has a large handle, maybe 1.25", It is actually a little fat for my hand and grip - but I think doable. It does have significant rounding of the corners that may or may not be of help. We have old rusty mason trowels so I might just buy a new one, to replace the old ones. Plastering looks like something I could do, but maybe there'll be a steep learning curve - I hope not too steep. I think i'll set up a scrap of board and practice, before the real thing. Again thanks so much for your help.

  • brickeyee
    11 years ago

    " The pool trowel has a large handle, maybe 1.25", It is actually a little fat for my hand and grip - but I think doable."

    You can always make it smaller.

    Cut it away with your choice of sharp tool and sand it smooth.

  • Jumpilotmdm
    11 years ago

    Easy sand produces a surface that is not smooth? Hmmm, how smooth are you looking for it to be? Most skim coat i am familiar with has at least some texture to it?
    Your prep sounds good, great even. Just be careful adding too many coats of skim, and therefore weight, to that ceiling. Plaster ceiling fail for a couple of reasons so don't give it any excuses to do so.

  • brickeyee
    11 years ago

    If you work EasySand with conventional plaster techniques (steel trowel finish) it can be made almost identical to plaster, and under a coat of paint you cannot tell the difference (or even where the old plaster ends and the repair starts).

  • enduring
    Original Author
    11 years ago

    I have just put some finishing touches on some small imperfections. The method I used to do this wall is a combo of everyones input. I'll call it the Barbara Method. I'll post the long version below, but the short version is mix, manipulate, fuss, sand, fuss, sand, repeat 4 -5 times.

    Brickeyee, YES:) my walls have the feel of plaster. Thank you so much for your help with this project. I couldn't have done it without you. You've been very encouraging. I have worked these walls in my Method to near perfection (IMHO) This Easysand is like velvet/glass. Here is what I have done:

    1) Went ahead and did another Gardz coat over the initial drywall work and drying type JP that I had originally done.

    2) Mixed the Easysand 90. I did a crappy job of mixing BTW, was mixing by hand :( I tried to muscle the JP onto the walls. I tried the regular trowel, the pool trowel, the 6" knife. It all worked for me at different times. I think I am just not strong enough to do this. Thank goodness I had the 90min stuff.

    3) Sanded:) Looked beautiful and encouraged.

    4) Put another layer of 90min Easysand on the walls using a variety of trowels but finding that the 6" knife was the easiest for me to use. I made this batch thinner. Too thin, was like pancake batter. Not so encouraged. But I have such a thin layer on that I hope the strength is not impacted due to the thin mixture.

    5) Sanded:) Looked beautiful again.

    6) Spot treated all my divits using 20min Easysand. Very beautiful. I have to say that each coat is micro-layer thick because of my sanding. (I have practically a whole bag of easysand in my shop vac by now, with all the sanding:)

    7) Looks like heaven, so applied some more 20min Easysand to a few more very small imperfections. I will sand these last two layers later today and prime. I have shined lighting, angled to the wall, to help find these imperfections. I also use my hand to feel how smooth and regular the wall surface is as well.

    I love the depth of the color of the Easysand applied in the different coats and patches.

    I tried the sweeping trowel work that I've seen others do, but I can't get that tech. with this medium. Maybe if I was younger and stronger.

    I have a very DEEP RESPECT for plaster and drywall installers now! This was a lot of work for me. I think some of my issue was strength, but the other was expertise and skill. I am very glad I did this with the Easysand. It is lovely.

    Thanks Brickeyee again.

  • enduring
    Original Author
    11 years ago

    Jump...The ceiling is only treated at the areas where the old bare plaster is exposed because I pealed the paint away when I took the walls down. So I used the Easysand to make the surfaces level. The ceiling is original and is not getting any layers added with the exception of the very thin coat of Easysand to level several layers of paint edges.