Do plant-based paints grow mould?
I have heard that plant-based paints can grow mould. Is this the case?
We very occasionally get calls about mould forming on the Aglaia plant-based emulsions within the tin/bucket.
Rest assured it is not a problem with the ingredients - it is simply that as it is plant-based, and does not contain nasty fungicides, it has the ability, under the right circumstances, to grow mould when it is in liquid form.
This will only be down to two things:- one is a source of bacteria on the paint after it has been opened (this could be from a brush that wasn't quite clean or from airborne bacteria/spores) and two is temperature - if the paint has got warm then this can then cause the bacteria to reproduce and grow.
Technically the paint under the layer of mould will be fine. The mould is not any particular health hazard. If you skim the mould off the surface the paint underneath should be fine.
So the best advice is - be scrupulously clean with brushes - it is best to decant the paint you need into a paint bucket/kettle and then reseal the tin and store it in a cool place. In this way, you never put the brush directly into the tin of paint.