Paint peeling when sanded

Discussion in 'Painters' Talk' started by EMcG, Apr 16, 2019.

  1. EMcG

    EMcG Member

    I painted the old white woodwork in my son’s bedroom 4-5 years ago, sanded down very well, vacuumed and cleaned with white spirit.

    I used 2 coats of water based undercoat and 2 coats of Crown quick drying satin and it’s looked fine since (apart from a few dings from teenage boys).

    I’ve just come to redecorate the room and began keying the woodwork and instead of sanding, the paint is just peeling off in fine threads.

    Can anyone suggest the best thing to do to try and overcome the problem? In an ideal world I would heat gun it back to bare wood but I’ve got a 15 year old decamped to my lounge and need him back in his room as soon as possible! If that’s the only solution though then I’ll have to bite the bullet.

    Thanks for reading,

  2. EMcG

    EMcG Member

    Sorry, posted twice
  3. Wayners

    Wayners Well-Known Member

    Why did you use white spirit to clean? Meths or sugar soap is what you should use to clean. Also stranded uc is not as good as adhesion primer like zinnser 123
  4. DIYDave.

    DIYDave. Well-Known Member

    At the risk of annoying Astra .... but anyway..... here goes :)

    Water based paints are weird in many ways and take a different approach in their use

    Try sanding down using fine wet and dry paper, using the paper wet

    Sounds crazy I know but .....
  5. EMcG

    EMcG Member

    Thanks, I’ll bear that in mind for next time but always thought white spirit was the best for a final wipe down before painting.
  6. LEH

    LEH Active Member

    They're not very volatile (unlike meths), wouldn't surprise me if a residue was left, possibly soaked in a bit too, which then stopped your paint adhering. As Wayners said, an adhesion primer is always a safe first coat if you're not sure what you're going over.
  7. DIYDave.

    DIYDave. Well-Known Member

    Very childish attitude indeed, rude and abusive as well but oh well, up to you - it’s so easy on a forum isn’t it as we are all faceless

    But would you disagree with my point re using wet and dry for sanding down water based paint ?

    Or have I offered sound advice ?

    Would welcome your views as you have many years of professional experience whilst I only have many years of diy experience

    But if your leaving, that’s up to you clearly ..... will the forum cease to exist I wonder
  8. Astramax

    Astramax Well-Known Member

    DIY Dave is DIY end off. Did you report me snitch?
  9. Astramax

    Astramax Well-Known Member

    DIY Dave wins ........I'm out.:D:D:D:D:D:D:D:D:D:D:D:rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes::rolleyes: he's the time served expert!

    Couldn't leave it could you, always having a dig arn't you, smart mouth.
    Last edited: Apr 16, 2019
  10. EMcG

    EMcG Member

    Thanks, but do you have any suggestion about what I can do just now?
  11. EMcG

    EMcG Member

    I remember my dad using wet and dry when I was little (which is a long time ago!).
  12. EMcG

    EMcG Member

    I think I must’ve missed something... but dies anyone have any other advice? Thanks
  13. DIYDave.

    DIYDave. Well-Known Member

    Ha ha yes I’ve got similar memories as this but was more to do with bodywork repairs to the family car

    Not sure that water based trim paints were so widely used back then !

    What grade paper have you been using to sand down with ?
    As I said, water based paint is a very different beast to solvent based paints

    Good luck
  14. LEH

    LEH Active Member

    Yes, bit unfortunate that... The short of it is that you need to get down to a sound base - obviously if you put new paint over the old that isn't stuck on properly, your new paint isn't stuck on properly either.

    If it's coming off easily, you could probably just go back down to the older paint layer, providing it's sound, not flaking or blistering etc (can try scratching with a nail etc). Then get a coat of Zinsser Bullseye 123 (as Wayners suggests) before putting the rest of your coats on.
  15. gac1967

    gac1967 Member

    Sounds like you are going to have to strip it all of and then apply an adhesion primer and take it from there
  16. DIYDave.

    DIYDave. Well-Known Member

    I’m wondering though if it is purely an adhesion problem (or lack of) or just the fact that water based paints don’t sand down the same as solvent based paints

    Aggressive sanding can cause the water based paint to tear off as you’ve described

    As above, can you easily scratch the paint off with a scraper or similar object ? Or only when sanding ?

    Any one else here tried sanding WB with wet and dry paper ?
  17. WillyEckerslike

    WillyEckerslike Well-Known Member

    You're not the only one. I think I need to increase my medication.
  18. gac1967

    gac1967 Member

    I would say white spirit has something to do with it, me personally I wouldnt go to the extreme of hot air gunning all the paint off, I would scrape it all off and sugar soap woodwork, clean with clean water allow to dry and then coat all the woodwork with adhesion primer.
    Water based paints are good in the respect of low odour and dries quick, but some people tend to keep putting coat on after coat as soon as its touch dry, read the instructions.
  19. Wayners

    Wayners Well-Known Member

    Use duck tape to stick on and pull off paint if its coming away. Scrape the reset off or scrub it. Consider paint stripper to as last result... Get it clean.. Prime and paint again. Don't use solvent as cleaner if using waterbased paint and up the quality of the paint you are using.. What's all the unpleasant talk here.. Gee! Happy to give further advice op @EMcG
  20. DIYDave.

    DIYDave. Well-Known Member

    Hi Forum

    The unpleasantness was aimed at me following my suggestion on post 4, simply by suggesting using wet and dry paper (wet) to sand down the water based paint

    A well known forum pro literally went ballistic at me and was rather rude and personal, his post was soon deleted by a moderator

    My thinking is that WB paints behave very differently to solvent based, both in prep stages and painting

    May not purely be a poor adhesion problem between old and new paints, just that WB doesn’t sand down like solvent based, ie, into a fine dust

    Has a habit of clogging the paper and if sanded too aggressively, can tear into strands off the workpiece

    Would seriously be interested to know if any of you pro guys have used wet and dry with WB paints and was my suggestion valid ?

    Thanks, all have a good and pleasant day

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