Tips for skimming a wall

mayoman1973

Skimming is one job I would love to try just to say I did it. I don't want to hear that it's difficult, don't do it. What I'm looking for is basic tips, how long to let the mix set for, how to gauge the thickness of a coat, how long till you come back to finish a wall etc. stuff like that. If it turns out rougher than a badgers ar$e then I'll abandon but for now I have a rear storage room with no window that I want to try my hand at it first in. Cheers

650gs

Its quite easy really and the more you do the better you become, Its called skim coat because that's just what you put on a skim try not to put on too much and smooth it out only a little, after about 10 may be 15 min smooth it a bit more and then you have to judge it your self if its too soft you cant smooth it out and if too hard yer f(*&&T%ed you should be able to just put a small dent in it with your fingers and go light on the trowel, thats another point you really need a good trowel or your wasting your time

policarp

Also if you're skimming an old wall you will need to "Polybond" first.
For skimcoat the wall must be fairly flat
If not your job will be, let's say, interesting.

TheLastMohican

A 25 kg bag will cover about 10 sq m. Mix until like whipped cream. If you can't take it off the hawk with the trowel just toss on guagers full and smooth - just once. When you have the first coat on, smooth over as good as possible again. Clean your ceiling and wall lines. The second coat should be easier to put on and just keep smoothing until it looks symmetrically flat. Don't do anything for 15 mins or so and then flick or spray on some clean water, gently trowelling as you go along. Leave for another 15 mins and again trowel up after applying more clean water. By now it should be looking pretty good. Again, clean off your ceiling and wall lines before giving it a final trowel. Clean off your angles before pulling an wet 1" brush along them.
Best of luck. In the 70s I served a 4 year apprenticeship in plastering and it took me a couple of years to get the hang of it and leave acceptable work .

But it really depends what standard of finish required.

mayoman1973

Cheers guys, few more Qs. Can I hardwall directly onto a concrete block wall? If so will I need to give it two coats? What time do I leave between the two coats ? Is the 2nd coat just for patching up uneveness in the first coat? Do I also need to give two coats when skimming directly over plasterboard? See for corners. Is the edging tape good enough or is it better to go with the ridgid stuff?

filbert the fox

TheLastMohican wrote: »

A 25g bag will cover about 10 sq m. Mix until like whipped cream. If you can't take it off the hawk with the trowel just toss on guagers full and smooth - just once. When you have the first coat on, smooth over as good as possible again. Clean your ceiling and wall lines. The second coat should be easier to put on and just keep smoothing until it looks symmetrically flat. Don't do anything for 15 mins or so and then flick or spray on some clean water, gently trowelling as you go along. Leave for another 15 mins and again trowel up after applying more clean water. By now it should be looking pretty good. Again, clean off your ceiling and wall lines before giving it a final trowel. Clean off your angles before pulling an wet 1" brush along them.
Best of luck. In the 70s I served a 4 year apprenticeship in plastering and it took me a couple of years to get the hang of it and leave acceptable work .

But it really depends what standard of finish required.

Gee, 10 square metres for less than an ounce mighty value

greenpilot

Place skimmer over card slot, make sure its switched on, sit in car, start gathering....oh wait.

I misread that post...

Thought that was "hole in the wall"....

moy83

mayoman1973 wrote: »

Cheers guys, few more Qs. Can I hardwall directly onto a concrete block wall? If so will I need to give it two coats? What time do I leave between the two coats ? Is the 2nd coat just for patching up uneveness in the first coat? Do I also need to give two coats when skimming directly over plasterboard? See for corners. Is the edging tape good enough or is it better to go with the ridgid stuff?

No you cant skim straight onto blocks , you will have to put a 1/2" coat of sand and cement on first and use a straight piece of timber to staighten out the angles and wall , then float it using a plastic float with nails through it that will leave small scratches for the skim to get grip on .
Or you could fix 1/2" plasterboards to the blocks either which might be easier than floating the walls for a novice .
Both ways still need the two coats of skim .
I think the sooner the second coat goes over the first the better (other people will say to let the first coat dry a bit but I like to get it all on and give myself more time to flatten it out while its still nice and soft ) Once the first coat is on give it a quick flatten and mix fresh skim for your second coat and get that on as flat as you can .
Give yourself ten minutes once the second coat is on to clean all you tools and buckets and give the wall its first flatten/trowel . You will still be leaving lines in the skim with this trowel but try and flatten it as best as you can and fill any holes .
After that let it dry till a skin comes on the skim then trowel again with more pressure this time again filling any holes that are left .
It will be going well off by now but give it another trowel and hopefully it will be looking pretty flat and smooth to the touch .
For the corners you will need skim angle beads . Tape wont give enough cover for the skim .

TheLastMohican

filbert the fox wrote: »

Gee, 10 square metres for less than an ounce mighty value

Thank you filbert. A slip of the finger by me. And thanks also for your harmonious response.

TheLastMohican

mayoman1973 wrote: »

Cheers guys, few more Qs. Can I hardwall directly onto a concrete block wall? If so will I need to give it two coats? What time do I leave between the two coats ? Is the 2nd coat just for patching up uneveness in the first coat? Do I also need to give two coats when skimming directly over plasterboard? See for corners. Is the edging tape good enough or is it better to go with the ridgid stuff?

If you mix a bag of Carlite bonding or Carlite browning, you can give the wall a tight coat first - 3 or 4 ml and close it in well. Use a devil float when floating. After it changes colour (probably 3 hours) apply the finish. If you let the backing coat go dry you have to prime it with an appropriate adhesive.

xual

I've recently had to strip off a lot of wood chip wallpaper ( painful ). I skimmed over the wall's to deal with some bubbling and damage when removing the wallpaper. Its a 400 sq foot room with about 650 sq foot of wall. The skimmed walls are drying now.

My question: how long should I wait until I paint?