PVA before K Rend
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warriorupnorth
Private Member
No
dmplastering
Member
No pva on external
Thats was quick cheers , any suggestions. Bit worried now as I have done this before dashing for years. It was what I was taught ?
warriorupnorth
Private Member
Just give it a good drink , pva on externals re-emulsifies unless encapsulated in cement , so can cause delamimation
Rossi46
Private Member
Where you from boarder? Is that boarder as in plasterboarder or are you a surf dude?
Fatarm
Trainee mod
Does waterproof pva react the same way warrior?
warriorupnorth
Private Member
Not if its the ethylene vinyl acetate, am assuming that's what you mean .?
Dansouthcoast84
Private Member
you swallowed a dictionary paul? big words today!!!!1
warriorupnorth
Private Member
No mate just looks like I have
and Mr Redman is right just use SBR (styrene butadiene rubber)
DannyMac
Private Member
No mate just looks like I have
Last rendering job I did I experimented with putting a little SBR in the scratch instead of waterproofer to control suction. It didn't kill it enough (i probably didn't put enough in) so I primed the scratch with a 5:1 SBR mix which worked real nice. The client couldn't get planning on a balcony so had to turn around some double doors, the fitters broke a small bit of finished render off the reveal while doing so.
I tried to seperated the scratch from the topcoat off this broken piece and no way could I do it. It was like it was welded together.
Fatarm
Trainee mod
Cheers warrior, you are a fountain of knowledge:RpS_thumbup:
Hi Bud, over the last three and a half decades have skate , snow and kite.........boarded that is windsurfed at Rhoseneiger but never actually surfed, dont know why. Ride a Duke as well but not a good as Rossi ! Plasterboard also but its not as much fun !
Rigsby
TPF Special Forces
We did a back of a terrace on Friday with 5 washed sand 1 cement with 3 ltrs of SBR in the mix (scratch coat). Really nice stuff to use and set hard with 12mm glass fibre strands added. Come to render it on Monday with 5 1/2 washed sand to 1 cement and 2.5 ltrs of SBR and there was suction. Didn't expect to get any but did so had to wet it down.
Looking at your post are you saying you primed the scratch coat with 5 water to 1 SBR? Did you let it dry or go over it tacky?
Powerfull stuff this SBR. I have to pay a small fortune for cementious grout for brick stitching and all it seems to be in the container is 0.5ltr of SBR and a bit of sand & cement? £24 for about 50p worth!
I reckon the primer for bucket coat is a watered down SBR with pigment added. Webers primer for Alpine finish is PR310 which is their primer for bucket coat. They say otherwise use Weber.latex (sbr) 1:1 with water. For Alpine it needs to be tacky.
DannyMac
Private Member
Yes mate, 5 water : 1 SBR. It was about a 20m2 wall and there was a fair amount of suction in the scratch still. So by the time I had rollered the last bit on, the first bit I had primed was way past tacky, it had pulled right in.
Not sure about the other primers you have mentioned but if they were expensive and I used them a lot, I might try a few test panels on a wall one day with some cheaper primers. Both tacky and cured, and try to scrape them off a few days later.
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