Hi mate. Here' the theory, let us know how it goes!
If I were you.....
1. Clear walls of ALL loose material and any paper.
2. Apply a generous coat of pva, at a 50/50 ratio. Allow to dry.
3. Prepare your work area and organise your tools, mixing area etc.
4. 10-15 minutes before your ready to mix, apply another coat of pva at a weaker ratio.
5. Mix your stuff with cold, clean water. Generally it's a builders bucket to a whole 25 kg bag of multi and one bag will do, on average 10m2 depending on the state of the wall and your purse strings!
6. Apply your first coat and do not worry about getting it perfect. Good plasterers have lots of experience thus 'lay on' flat but don't worry at this stage, just concentrate on getting 2-3 mm of stuff all over the wall. If your right handed, start in the upper left corner and work your way, in a logical fashion to the bottom right, vice versa for you left handers.
7. Now, do not bite off too much. Only mix enough multi to last 20-30 minutes. After circa 30 minutes of laying the first, you will notice the plaster starting to firm up.. This is a good time to 'flatten off', I generally just use a 14 inch trowel and go back over the plaster, in an attempt to get rid of any high spots, lines etc.
8. Mix a fresh batch of multi. You should only need 50% of what you used on the first hit, but if unsure just mix what you think. Starting in the same place as before, apply another coat of plaster, attempting to fill any voids.
9. The next step is 2-3 more trowels to get a perfect finish, there are rules for when each should be done but it's more about experience than timing as many factors determine the ideal times. The first should be done with minimal water...if any at all. You're effectively doing the same as you did before when you 'flattened off' the first coat but this time you'll pick up a nice trowel full of fat which you can use to fill any divots or trowel marks, just use the same trowel as before, no need for a Darby or speedskim on a bathroom. The second will need some water to act as a lubricant and the third and final trowel is a dry trowel but unless you're experienced and have a good sharp trowel, I'd bin it in favour of a little light sanding/filling when dry if needed.
Thats it, no Darby required! Some people take to it very quickly, some never get past the stage of getting the plaster off the hawk and onto the wall.......it is not for everyone. Be interested to know how you get on.
Cheers
