Pva

[Woody123]

Alrite fellas

I have never done a proper paid job yet plastering as im still learning really and what might seem a stupid question to the more experienced people its been bugging me! ha. Anyway we got told when mixing PVA you should go 50-50, let that dry then 1part pva - 4 part water. My question is do you physically measure the amount of PVA to water in or jug or summat or do you just do it by eye with a rough estimation? How important is it to get the mix right and what would be the outcome if you didn't mix it right? Am i right in thinking the 1st of all the plaster wouldn't stay on the already plastered wall and secondly it would suck the moisture out too quick?
An idiot's guide would be magic!!

Cheers

[specialrider]

hello m8.wouldnt let it bug you,more often that not i always just guess it approx.first coat as you say to seal area ,witch is the finest.second coat glue thicker i always just add more after first to thicken it up.worst will happen is the plaster as you rightly say will pull in quicker.you will get used to it.it also depends on what brands. as the cheaper ones like say b&q will need considerabley more pva than say sealocrete to get the thickness if you see what i mean.

[Whitebeam]

i only do two coats of pva if the wall is dusty and very absorbant, the first coat would be thin, (estimating the mix) apply, wait to dry then the second coat would be thicker and wait for it to get tacky. If the walls are painted I would do 1-1 or2-1, again wait for it to get tacky or nearly dry. Once the wet plaster goes on it will soften the pva slightly. Mixing is'nt that precise just near the mark tends to work. You should'nt get to much suction if any, multi with to much suction can cause crazing. Others may do it slightly different but that way works for me.
Don't though put the plaster on to early on wet pva it will end up sliding down the wall

[specialrider]

should read thinest coat not finest.

[Woody123]

Cheers for the respnses lads. Whitebeam, out of intrest what is crazing?

[Whitebeam]

Crazing is when there is just a little to much suction and the surface has very hair line cracks in certain areas, nothing to nasty but can spoil the job

[Dan]

Is sealocrete THE brand then when it comes to PVA?

[specialrider]

sealocrete is my choice where poss.but others do the job just find that some brands you seem to use double the volume,as if already been thinned out.suppose to the tiling lads certain adhesives seem better than others.just a preference really an value for money.

[Spreadboy]

I always guesstimate mine but I never have it too strong as I find it goes flaky as it dries.Roughly 4:1 I go for.Leave 1st coat dry and leave 2nd to go tacky is my usual approach.On walls I use two coats on ceilings especially if artexed minimum of three.Try and use a good quality brand but don`t worry too much if it`s cheapy stuff,just add that little bit more.Good luck in starting out.You will learn as you go along like we all did/do.

[Whitebeam]

I use wickes pva, used to use bond it and got a bad batch, just did'nt have any body to it