Caulk Cracking

Discussion in 'Painters' Talk' started by Leigh, Aug 8, 2008.

  1. Leigh

    Leigh Member

    Hi, can anyone help recommending a good decorators caulk?

    I've just spent ages caulking around newly installed skirting boards and door frames, left the caulk over a week, I just was about to start painting downstairs when I noticed its cracking, all skirting & woodwork is securely screwed and glued to primed masonry walls I've used the most expensive latex caulk I could find "Geocel Painters mate" bought from screwfix.

    Can anyone recomend a caulk that won't let me down, whats the best type paintable silicone, silicone latex mix and where can I get some?

    Many thanks in advance, I can't be the only person suffering this problem.
     
  2. T-C

    T-C New Member

    Hi Leigh, it not the calk, when you have done all caulking let dry over night then either; coat with undercoat, or bin, or softsheen, or diamond matt. before overcoating with you chosen finish. will not crack. job done T-C
     
  3. jcts

    jcts Active Member

    it happens all the time. it happens a lot in new build house's with all the movement of the wood, plaster etc. also if it's very warm in the house, that can be another cause. try using pollyfilla caulk. doesn't crack too much
     
  4. Leigh

    Leigh Member

    Hi,

    I've left it to dry for over a week and still haven't painted it.
     
  5. Leigh

    Leigh Member

    Thanks for the reply;

    I think youre right, but after doing a bit of researching, the acrylic caulks like I'm using are not really up to the task, the latex offers a good surface to paint, but it's elasticity is severly compromised 5-10%.

    Apparently some products (isosyteric or something) which combine the best properties of latex and silicone, all overpaintable offer that extra flex up to 50%, the best one is an American product DAP Dynoflex 230 can't find it in the UK though, and shouldn't be used in bathrooms as is susceptable to mildew.

    But the best products to go for are the 1 part polyurethene caulks/sealants that offer 80 - 100% elasticity, last 25 years and don't sag & are paintable only downside is they cost 3 times, but I would rather pay more for something that lasts longer than the paint.

    Platform stock Sikaflex EBT, I think Everflex do one PU40
    from toolstation, not sure about Screwfix!

    Cheers
     
  6. jcts

    jcts Active Member

    forgot to say, don't use silicone. worst move you could make
     
  7. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    I find it better to slap an undercoat on surfaces first. That seals the wood etc and stops the caulk 'artificially' drying out too fast, making it shrink.


    Mr. Handyandy - really
     
  8. jolly bodger

    jolly bodger New Member

    interesting, I might try that on tomorrow's work
     
  9. CaulkHero

    CaulkHero New Member

    There's a few ways to stop your caulk from cracking, they include...

    1. Prepararing your Surface Correctly - remove any old caulk, grout or flaking plate, clean the surface, THEN apply new caulk

    2. Trying to Filling Too Large Gaps - Gaps larger than a quarter-inch or more than half an inch should first be filled with backing material like foam tape before adding the caulking material.
    3. Using the Right Type of Caulk - There are three main types of caulk: silicone, latex, and acrylic. Each type is suited for different purposes, pick the one that does that you need to do.
     
  10. I-Man

    I-Man Screwfix Select

    After 14 yrs i think they've gotten over it!!

    upload_2022-4-22_12-54-30.png
     
    CaulkHero likes this.
  11. Astramax

    Astramax Super Member

    Your cracking me up :D
     
    I-Man likes this.
  12. CaulkHero

    CaulkHero New Member

    Lol, hadn't realised it was so old. :D
     

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