Stains bleeding through external woodwork

Discussion in 'Painters' Talk' started by Mikeey, Jul 19, 2011.

  1. Mikeey

    Mikeey New Member

    Hi, I've been painting a sash window on the outside. Some of the paint pealed right off down to the bare wood while I was preparing it. I,ve put on a coat of waterbased primer and two coats of Dulux Weathershield waterbased stain (white) and brown stains have come through where the wood was bare. I had this problem once before and tried Zinsser 123, but even that didn't block the stains. Any ideas would be much appreciated, best wishes, Mikeey
     
  2. blertsville

    blertsville Member

    Try pvc windows , they are great
     
  3. Goodwill

    Goodwill Member

    Hi Mikeey,

    Zinsser 123 is water-based , I would suggest that you spot prime these stained areas with Zinsser B-I-N, which is a shellac-based primer/sealer.
     
  4. Mikeey

    Mikeey New Member

    Hi Goodwill. Thanks - yes I got the names mixed up. The one I tried last time was the shellac one - the B-I-N that smells of (and can be thinned with) meths. But the stains still came through???
     
  5. Astramax

    Astramax Super Member

    As Goodwill pointed out Zinsser Bullseye123 would not be satisfactory for this application due to being watebased. Have you checked out for any wood decaying and treated or replaced any timber that is not sound? If all sound you will find Zinsser Cover Stain would be a better paint to use for this problem as it has an oil base and you will not get any bleed through with this product.
     
  6. Mikeey

    Mikeey New Member

    Hi - it was the B-I-N I used last time - I got the names confused in my original post. The wood is all sound. Do you think any oil based paint will block it, for example weathershield solvent based ?
     
  7. apl

    apl Member

    If you have sealed the knots with BIN (2 coats?) then they shouldn't re-appear. BIN has a yellowish tint and it may be possible the BIN has grinned thru the primer and waterbased satin you applied. If you put on two coats of aluminium wood primer on the section of stained wood followed by two coats of oil based weathershield undercoat, then two coats of your waterbased satin, this should solve it permanently.
     
  8. Astramax

    Astramax Super Member

    Cover Stain is a different Zinsser product from B.I.N.and 123.
     
  9. Astramax

    Astramax Super Member

    ,.........and you can paint over it when dry with your Weathershield paint.
     
  10. Mikeey

    Mikeey New Member

    Yes I guess I should have used the Aluminium wood primer in the first place, and then maybe solvent based undercoat also. But do you think I need to go and get some cover stain or will a solvent based top coat sort it out? And will it go straight on top of the water based top coat I've already put on? (The knots are fine - they haven't shown through the knotting I put on them.) Thanks again for all help.
     
  11. StinkNugget

    StinkNugget Member

    Mike, you don't usually need 2 coats of stain block, 2 coats of oil based undercoat then 2 coats of top coat to hold a stain at bay.  What is causing the stain, you mentioned "bare wood" in your first post & elswhere it's changed to "knots".  You also said in your last post that the knots aren't showing through, so what's causing the stains? (It's late, I might be going mad lol - it could be that you simply didn't apply enough primer then undercoat which may have led to it still being visible through the top coat???)  Assuming this isn't the case, are you sure it's not mould/mildew etc, or is there any sap/resin bubbling through?  If so deal with it with a hot air gun & wipe down with white spirit to remove any residue.

    It sounds from the very brief description like knots showing through, if so BIN *should* hold it back.  It's obvious but best to say it anyway: you need to give BIN a really good stir as it settles in the tin leaving all it's blocking power in a thick gunge in the bottom of the tin.  Usually 1 coat of BIN, 1 undercoat & 1 top coat is sufficient.  As apl said BIN dries to an off white/yellow tinged colour.  If the stain is still showing through apply a second coat of BIN, it really should hold it back.  Alternatively, you could try Aluminium Wood Primer (Dulux Trade is a good product) which is another problem solving primer for use on all kinds of wood where bleed through is likely.

    Good luck m8 :)
     
  12. Goodwill

    Goodwill Member

    Mikeey,

    No two P&Ds are likely to give you exactly the same advice (preferences and there is often more than one way to solve a problem) but Stinknugget has now proffered a very comprehensive answer to your problem, bearing in mind that your description did lack the full details.  Do you now feel confident that you are able to solve this problem?
     
  13. Mikeey

    Mikeey New Member

    Its definitely not knots - its just something coming out of the wood other than resin or sap. I think the problem has been that  I used a water based undercoat rather than one with Aluminium. And it definitely wasn't the BIN showing through last time when it happened, and i did stir it well. I came on the forum because last time it happened I expected the BIN to sort it out and it didn't. I don't want to strip it down to bare wood and start again, so I'm just wondering if its best to put some Aluminium stain block or wood primer on top of the stainwood, or some of this Zinsser cover stain ??? Another thing - some similar colour staining came through the stone sill also. Thanks for all responses.
     
  14. Goodwill

    Goodwill Member

    Mikeey,

    Personally I would strip this sash.  However, in view of what you have said in your post above I recommend that you apply two coats (to avoid the risk of misses) of an aluminium wood primer, such as Dulux Trade Aluminium Wood Primer, before proceeding with oil-based paints up to your finishing coat, including the stone cill.       
     
  15. Guttercat

    Guttercat New Member

    It's water staining over the years, then using water based over the top.
     
  16. Mikeey

    Mikeey New Member

    Sorry to be a pain, but I'm not clear whether the Aluminium wood primer can be relied upon to stick to the satinwood I've put on, or is there another Aluminium paint that would be better? Thanks again
     

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