Plaster for patching

danrv

FreeBear said:

FreeBear said:

danrv said:

FreeBear said:

My first big wall. Chases and missing lumps from where skirting & picture rail removed filled with bonding coat. A base coat to level out the original "rustic" plaster, followed by two skim coats. Not looking forward to doing the arched alcove. Might end up using Fill & Finish for that...

I have a 1.9m x 2.3m landing wall that has a blown plaster line up the middle. 
That might be a case of plastering the whole wall. Will see how much of it comes off.
Judging how much to mix up I found a bit tricky. Was tending to do enough for a couple of hawks full so as not to waste any.

Measure up the area - 1.9mx2.3m is ~4.37m². For a ~2mm skim coat, you want to use two mixes using ~3l of water for each. Go for 3.5l for the first coat just to make sure you have enough, and 3l for the second coat.

A 25Kg bag of Multifinish covers 10m² @2mm and needs 11.5l of water. So roughly 1l per square metre. Always better to mix a bit more than you need rather than having to mix another batch half way through.

Just done the chimney breast. Calculated 3m², so bunged 3l of water in the bucket with the intention of doing the side (1m²). 

Quite large quantities needed there. At the moment, I just add a couple of cm of water to the bucket, gradually add plaster and stir with a stick.
Works well for small patches.

Doing a whole wall for the first time takes a bit more thought and these quantity figures help. 
Was thinking of getting a cheap mixing attatchment as I have a power drill with a slow speed setting.

FreeBear

danrv said: Doing a whole wall for the first time takes a bit more thought and these quantity figures help. 
Was thinking of getting a cheap mixing attatchment as I have a power drill with a slow speed setting.

For small mixes - https://www.toolstation.com/minotaur-mixing-paddle/p34216

For big batches - https://www.toolstation.com/einhell-1400w-mixer/p86547 (similar available on ebay from ~£30)

For a big wall, 3m x 2.4m, you can reduce the quantity a bit, especially if you are going over virgin plasterboard.