First Time Plasterer Seeking Advice

Discussion in 'Other Trades Talk' started by AndyF55, Feb 26, 2014.

  1. BuilderMCR

    BuilderMCR Active Member

    Now we go back to the "don't use too much pva"

    You have a porous surface and you seal it so much it becomes non porous so you have no suction
     
  2. BuilderMCR

    BuilderMCR Active Member

    But you don't use pva on walls with no suction! You use bond it etc.

    If you have no suction you plaster tears when your troweling up
     
  3. BuilderMCR

    BuilderMCR Active Member

    The pva is to close up some of the holes in your sieve (seal them) so you don't have too much suction
     
  4. BuilderMCR

    BuilderMCR Active Member

    If you keep this up Andy I'll have as many posts as you! ;)
     
  5. Phil the Paver

    Phil the Paver Screwfix Select

    Not to do with plaster, years ago I had to replace a terracotta tiled floor, we took the old tiles up, clean the existing concrete base ready for new tiles, the customer who was a scientist told us in no uncertain terms not to use PVA on the existing concrete and to only wet it using water and then bed the tiles, when we questioned this he explained that PVA was not a glue as such and would not aid the skicking down of the tiles, he said it would have the opposite effect and form a barrier between the concrete and the tile adhesive of which neither of them would stick to, were as water would evaporate slowly allowing the adhesive time to bond with the concrete. ???
     
  6. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    :)

    No. Yes you do use pva on non-porous walls. It gives adhesion where there is no suction.
    Yes you use pva on porous walls. It prevents too much suction and aids adhesion.
    The grit in bond-it further aids adhesion.
    You know it makes sense.

    Mr. HandyAndy - Really
     
  7. BuilderMCR

    BuilderMCR Active Member

    Exactly Phil, so by pvaing your sieve you are only sealing some of the holes, this allows some suction to adhere the plaster but not so much that there is no suction
     
  8. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    Same goes for wall tiles.

    Mr. HandyAndy - Really
     
  9. BuilderMCR

    BuilderMCR Active Member

    No, pva is only for controlling suction.

    If you have no suction you have nothing to control

    If you have no suction you have no key

    So you use bond it to create a key which doesn't require suction
     
  10. BuilderMCR

    BuilderMCR Active Member

    I feel like a fish in a bowl, I'm going round and round in circles.

    But you are understanding more the dizzier I get.
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    It's a glue. And pva is a glue!

    Mr. HandyAndy - Really
     
  12. BuilderMCR

    BuilderMCR Active Member

    Bond it is not a glue. The key comes from the aggregate.
     
  13. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Is bond-it a type of PVA with grit in it?

    Mr. HandyAndy - Really
     
  14. BuilderMCR

    BuilderMCR Active Member

    No!
     
  15. Mr. Handyandy

    Mr. Handyandy Screwfix Select

  16. BuilderMCR

    BuilderMCR Active Member

    It isn't pva
     
  17. Mr. Handyandy

    Mr. Handyandy Screwfix Select


    Do you know what it is?

    Mr. HandyAndy - Really
     
  18. BuilderMCR

    BuilderMCR Active Member

    It's an aggregate based polymer 'primer'
     
  19. Phil the Paver

    Phil the Paver Screwfix Select

    I bet the OP wished he'd never asked. :p:p
     
  20. BuilderMCR

    BuilderMCR Active Member

    I wish the op never asked lol
     

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