On top of the above post, you can always wet down the base (scratch) coat with a bucket of water and a big brush before you apply the finish. Teh scratch should be wet to look at, ie dark, but without water runni9ng out of it. Any light patches will cause you problems with cracking of the skim.
[quote="rambo77"]hi can someone tell me the correct usage of pva when plastering if i use a bonding under coat will this need pva before applying the finishing coat if the bonding is left to dry for a few days[/quote]
Hi mate hope this helps if you skim it the same day or within 24 hours if you can avoid leaving it for any longer than that you should be fine if you have to leave it longer then either of the other two ways will work if applying pva though you need to make sure that you mix it correctly at 50% water and 50% pva. You should give it two coats one the night before you skim and another before you start. If you use the other method make sure your wall is completely covered with water and allow it to sit until the water stops running down the wall but the wall still feels wet to the touch. Good luck mate cuz if youve left it that long your arms will need to go like the clappers.