Difference between revisions of "Mould Resistant Paint"

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The best solution to mould is to prevent it. '''Mould resistant paint''' is a good second line strategy. It is possible to buy mould resistant paint, but it is also easy enough to make the [[Paint|paint]] you already have mould resistant.
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The best solution to [[Mould Basics|mould]] is to prevent it by drying the room. '''Mould resistant paint''' is a good second line strategy. It is possible to buy mould resistant paint, but it is also easy enough to make the [[Paint|paint]] you already have mould resistant.
  
These work with both water and oil based [[Paint|paints.]]
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These work with both water and [[oil]] based [[Paint|paints.]]
  
  
* Finely crush 16 aspirin tablets, it must be completely powdered, mix into 2.5 litres of paint. Let it stand 5 minutes then mix again.
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==Chemicals==
** The salicylate will react with water to form salicylic acid.
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Any one of these gives paint significant mould resistance:
 +
* Aspirin
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* Copper compounds
 +
* Alum
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* Zinc sulphate
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* Borax
  
* Add a pinch of a copper compound to a can of [[Paint|paint]], and mix in. Some copper compounds are toxic if ingested in more than miniscule amounts, so wash hands afterwards.
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Combine more than one additive for maximum [[mould]] resistance.
** If the copper compound is not soluble in the [[Paint|paint]] then it must be finely powdered before adding.
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* With alkyd or [[oil]] based [[paint]]s all additives need to be very finely powdered.
 +
* [[Water]] based paints dissolve the above additives, making this less important.
 +
* Lumpy soluble additives such as soluble aspirin should be added, time given to dissolve, then the paint mixed thoroughly.
  
* Add a pinch of alum to a can of [[Paint|paint]] and mix. For [[Paint|oil paints]] the alum must be finely powdered.
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When using aspirin, the salicylate reacts with water to form salicylic acid. 16 aspirin tablets per 2.5 litres of [[paint]] is suitable.
 +
 
 +
Some copper compounds are toxic if ingested in more than miniscule amounts, so wash hands afterwards. Too much copper can cause noticeable paint discolouration.
 +
 
 +
For outdoor paint, ferrous sulphate can be used to prevent algae.
 +
 
 +
Water soluble additives can leach out of the paint in time. Nonetheless the author's first use of this method (in a bathroom with aspirin) remained effective over a decade later. Don't wipe down wet walls, let them dry and the additive is not lost. A nonsoluble addditive such as copper powder is likely to last better outdoors.
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==Care==
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Most of these additives are water soluble, which raises the potential for them to simply be leached out of the paint by repeated condensation. Having used such formulae for years I can only say it works anyway, perhaps partly because the condensation evaporates away, leaving the mould proofer where it is, or perhaps for other reasons. However, one simple rule applies if you want it to work long term: don't repeatedly wipe the wall down when its damp, if you do you'll remove the mouldproofer.
  
* Combine more than one additives for maximum mould resistance.
 
  
 
==See Also==
 
==See Also==
[[Special:Allpages|Wiki Contents]]
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* [[Special:Allpages|Wiki Contents]]
 
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* [[Special:Categories|Wiki Subject Categories]]
[[Special:Categories|Wiki Subject Categories]]
 
  
  
 
[[Category:Paint]]
 
[[Category:Paint]]
 
[[Category:Damp]]
 
[[Category:Damp]]
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[[Category:Decorating]]
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[[Category:Chemicals]]

Latest revision as of 07:19, 9 August 2013

The best solution to mould is to prevent it by drying the room. Mould resistant paint is a good second line strategy. It is possible to buy mould resistant paint, but it is also easy enough to make the paint you already have mould resistant.

These work with both water and oil based paints.


Chemicals

Any one of these gives paint significant mould resistance:

  • Aspirin
  • Copper compounds
  • Alum
  • Zinc sulphate
  • Borax

Combine more than one additive for maximum mould resistance.

  • With alkyd or oil based paints all additives need to be very finely powdered.
  • Water based paints dissolve the above additives, making this less important.
  • Lumpy soluble additives such as soluble aspirin should be added, time given to dissolve, then the paint mixed thoroughly.

When using aspirin, the salicylate reacts with water to form salicylic acid. 16 aspirin tablets per 2.5 litres of paint is suitable.

Some copper compounds are toxic if ingested in more than miniscule amounts, so wash hands afterwards. Too much copper can cause noticeable paint discolouration.

For outdoor paint, ferrous sulphate can be used to prevent algae.

Water soluble additives can leach out of the paint in time. Nonetheless the author's first use of this method (in a bathroom with aspirin) remained effective over a decade later. Don't wipe down wet walls, let them dry and the additive is not lost. A nonsoluble addditive such as copper powder is likely to last better outdoors.

Care

Most of these additives are water soluble, which raises the potential for them to simply be leached out of the paint by repeated condensation. Having used such formulae for years I can only say it works anyway, perhaps partly because the condensation evaporates away, leaving the mould proofer where it is, or perhaps for other reasons. However, one simple rule applies if you want it to work long term: don't repeatedly wipe the wall down when its damp, if you do you'll remove the mouldproofer.


See Also