How long to leave PVA glue on for?

[mywetpants]

I'm about to skim an existing plastered garage and was wondering what the mixture of PVA to water ratio should be. 5 parts water to 1 part glue, or is it the other way round? Also, how long to do I need to leave it before I can put on the multi-finish.

Thanks

 

[kevsterjw]

on the back of the tin of unibond it says 5 water to 1 glue.

 

[mywetpants]

Cheers, Kev. Think I can skim when it's still slightly wet and sticky or would I need to leave it to dry completely?

 

[joe-90]

To be on the safe side apply with a roller letting the wall soak up as much as it wants then let it dry and apply second coat and skim when tacky.
A pro would simply slap it on and skim but two coats takes some of the skill out of it.

 

[mywetpants]

I've been having real difficulty with the workability of plaster, probably due to the high suction backgrounds when reskimming. The plaster simply dries too quick.

I've noticed Thistle GypPrime. Does anyone have experience with this, and how does it compare with something like Wickes Bonding Agent, or PVA?

 

[helter_skelter77]

We let it dry, helpfull tip.. 2 coats of pva, epecially on high suction walls let both dry or at least second one slightly tacky. Always put on with a roller. 4 to 1 or 5 to 1, Tight coat if needed for bad walls.

cheers

 

[Micilin]

For high suction, seal up at least 24 hours before . PVA not much good on a high suciton background unless it has well set, usually even a few coats the same day not good enough. Then, of course, apply plaster to a tacky fresh coat of diluted PVA. You can use SBR in a similar way. We use it to seal thermalite, durox, blocks.

Thistle Bond it is excellent, apply one coat at least 24 hrs before, and job done. You can apply plaster to it anytime after that with no further prep.

 

[mywetpants]

Thanks for the advice guys. That's where I've been going wrong. I usually apply a 5:1 mix and skim straight away on the same day.

 

[mywetpants]

Guys, how would you control the suction after laying on a hard/bonding coat? Would you put PVA on after scratching the undercoat?

 

[helter_skelter77]

Pva. We Pva all bonding, or undercoat plasters. We've never had any problems ever, usually I put on a couple of coats. You could also use bond it from British Gypsum.

 

[Micilin]

Pva. We Pva all bonding, or undercoat plasters. We've never had any problems ever, usually I put on a couple of coats. You could also use bond it from British Gypsum.

Why do you PVA bonding or hardwall etc?

 

[roughcaster]

I thought that as well Micilin.I've never heard of anybody (a pro) coating a wall and then PVA-ing it before putting on the finish.The first coat of finish sucks in a bit,but the second one usually goes on a treat,with plenty of time to make a job of it.......A totally dried out wall is a different story.

Roughcaster.

 

[helter_skelter77]

I use it on examples like patched in bonding on walls when rest of wall needs to be pva'd anyway, I just do the whole wall, It certainly dosent hurt to pva it. Just personal preferance really and always done it like that.

 

[roughcaster]

Fair comment h/s77,

Roughcaster.

 

[noseall]

if a backing coat is 'caught' at just the right time, it is a doddle to skim.

it is best skimmed late the same day, or early the next day, provided the backing was applied last thing.

you definitely do not want to let it dry out too mutch.