Flaking paint only just applied

Discussion in 'Painters' Talk' started by Philippa17, Dec 1, 2009.

  1. Philippa17

    Philippa17 New Member

    Hi everyone,

    we've just painted our front room and the new paint is already flaking (within 24hrs) in straight line and in small patches round the room.
    Can anyone suggest why?
    I've read a few things online and has a nasty suspician it may be because we painted over distemper, but I'm afraid we'd never heard of distemper before so were totally clueless. The wall underneath was very flaky and powdery - we scraped off the flakes before painting using a brillo pad and the pattern of flaking doesn't fit with it flaking off because of the old paint flaking. We used B&Q matt paint if it makes any difference.
     
  2. Yes it sounds like distemper / old whitewash. Ideally you would have put some sort of stabilizing solution on before you painted it. Now that you have painted it just sand off the patches which have flaked or bubbled, ideally you would stabilize these with a specialized product, however in reality if you have some undercoat around put a dilute solution on or if you don't have anything you can persist in putting emulsion on - but you may have to sand back and reapply areas which come off again.
     
  3. threadbreeker

    threadbreeker New Member

    you should have got a qualified painter in to do the job...serves you right for doing them out of work
     
  4. Astramax

    Astramax Super Member

    Strip off all paint, wash off distemper with warm water, leave to dry out fully. Apply a coat of Primer Sealer (oil based) and let dry. When dry re-apply your finish paint.
     
  5. notsure230

    notsure230 New Member

    i agree had same problem just use an oil based paint i used glidden not suplied in normal diy shops got it from local decorators outlet but any good oil based paint should do it .
     
  6. Abrade flaked areas and spot prime with Zinnser BIN
     
  7. agree with britney - scrape off, wash, seal with oil (thinned out to improve adhesion/penetration into plaster) based undercoat/primer, wait till dry then recoat with your molly.
     
  8. potty painter

    potty painter New Member

    Trying to patch this is not the answer, the Distemper until removed will always become a major problem. You, as Astra has said will need to remove it, seal it, and start again.

    Potty.
     
  9. polly222

    polly222 Member

    Philippa 17
    If you do as astra and potty say you cant go wrong dont just seal patches because the rest will come of after a while. Then it will take a lot longer in the long run
     
  10. So you have the choice:

    A couple of hours patching - and then see if it comes off and truly is distemper. Cost = 0

    or

    2-3 days (depending on size of room), for the DIYer scraping off everything and reapplying 3 coats with DIYer brushes and rollers. Cost = more paint, cartridge fume mask, + hot air gun or strippers.

    NO OFFENSE INTENDED!
     
    DarkLord! likes this.
  11. As it happens BandQ matt is very close to an old fashioned whitewash / distemper recipe and I am pretty sure you can put whitewash over whitewash even if it is a little dusty. I say this from a knowledge of the chemistry involved rather than direct experience. Please correct if wrong someone. I do know that if you had used a modern vinyl matt you would be in trouble.

    Was there a glaze in the areas which flaked after painting - either a shellac based (usually brown, but sometimes mixed with dark green pigment) or a vinyl matt paint?
     
  12. ~

    ~ New Member

    glub
     
  13. Goodwill

    Goodwill Member

    Britney,

    If you apply soft distemper over itself the result will be patchy and scuffy in appearance because the ground colour will work-up and piling will occur. The old coating has to be removed, the surface re-prepared before a coat of size or claircolle followed by the distemper.

    I find it hard to believe that the B&Q branded product which you mentioned is virtually the same as soft distemper. Perhaps it is nearer to an oil-bound water paint with lithapone as the white pigment, but I would doubt this as well.

    Where did you obtain your information?
     
  14. Distemper is a glue bound whitewash. Some natural glues last very well over hundreds of years if kept in a constant environment. Constant damping will cause the glues to break down.

    Calcium carbonate is the main component of the BandQ paint and distemper. This is a fairly certain deduction from the fact that the opacity increases upon drying. Both paints will also contain some inert pigments. The principal difference between the paints is the type of binder used. BandQ use a modern binder naturally, but very little - it is extremely matt and I think less than 0.7% VOCs. When I say they are similar, I mean in terms of ph, porosity, and degree of water attractiveness (they are both hydrophilic). BandQ will not send me the exact recipe. The important points of similarity are absorbency, rate of expansion and ph.

    My feeling was that the binders from the BandQ paint will seep into the porous distemper and stabilize it to a sufficient degree and feel that the main problem would be residual films of oil/grease/wallpaper paste/impermeable paint. This would create a layer of distemper under a relatively waterproof layer which would absorb more moisture which may cause salts to build up and adhesion problems.
     
  15. But basically it's a simple situation, if the paint sticks for a good few months after patching (oh so quickly done) leave it. In my opinion job done. Respect to anyone who would strip it all off - clearly this would definitely work.

    I'm off this site, if anyone needs work in Bristol contact Apple Decorating next spring. Respect to everyone especially Potty who despite numerous disagreements always showed excellent character. Bye.
     
  16. Goodwill

    Goodwill Member

    Britney,

    Much of this has been covered on previous posts. You may recall that in one thread, related to this subject, you stated, 'Don't paint chalk'. Well once it is dry soft distemper is not much more than that. Your posts tell me that you have never mixed or used distemper, be it soft or washable.

    The answer given to the OP by Astra was the best advice.

    Good luck.
     
  17. Goodwill

    No I wouldn't paint over chalk, unless it was a fine dusting. I think it was DAMP that other one, some outhouse or something, it sounded to me like an unbound whitewash.

    This case is DIFFERENT. It has already had paint put on it, so it is a fair answer Goodwill to just say leave it, patch it see how it goes. All right. If you don't agree fine.

    This is not about mixing distemper.

    You absolutely definitely cannot say that the distemper is an unsound base. It is ridiculous. There are some distempers which will be unsound and some that will be depending on the recipe. Therefore we will have to agree to disagree about spending days redeccing on a hunch. Fine. This is my last totally bored to death post and reading. aaaaaaaaaaaaaaaaaaaaaaaaagghh.
     
  18. Goodwill

    Goodwill Member

    Britney,

    I'm sorry to tell you that your thinking is not correct. Remember, I am only talking about distemper, not water paints in general.

    Strictly speaking distemper is a composition of whiting bound in glue size or casein. Size bound is called soft distemper because it remains soluble in water and can be easily removed by washing, a reversible coating. The OP said that "...... That the wall underneath was very flaky and powdery." Sounds very much like soft distemper.


    Washable distemper usually consists of whiting with the addition of borax and lime and is bound by casein. Because of the action of the lime and the casein it becomes hard and insoluble in water although if it is given a thoroughly good washing it will often reverse. Alkalis will also make it soluble.

    Astra's advice shows his experience in encountering such surfaces. Do the job properly and it will last.
     
  19. Goodwill

    Goodwill Member

    PS

    Looking back through the thread this advice was endorsed by Potty, Polly and IYWAJDP, although he said that he agreed with Britney he had described Astra's advice.


    Regards
     
  20. Astramax

    Astramax Super Member

    Astra's advice shows his experience in encountering such surfaces. Do the job properly and it will last.

    Too true Goodwill, you are correct with both sentences.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice