by Keith
(Cambridge)
Hi Paul,
Your video on setting up guides and ruling the backing coat was very useful, but I'm struggling to rule Thistle bonding plaster in the same way, as the length of (painted) skirting board I'm using to rule it tends to lift it away in lumps - I guess timing is everything, and you do say sand/cement is easier for the novice! Any further tips for timing it?
Also, I'm wondering if adding some sand to bonding plaster might improve it's workability, and also bulk it out for thick backing coats?
Answer
Hi Keith,
Yes, Bonding Coat can be tricky stuff for a novice. Controlling the suction can really help - as if some areas are drying quicker than others it can cause the lumps you're describing. So you could try applying PVA or water to the wall first - but you will eventually get use to it or just go back to using sand/cement!
Some plasterer's have been known to add sand in order to make it go a bit further, but I would avoid adding sand to the Bonding Coat unless specified by the manufacturer.
Good luck though!
Paul