Antifoul paints are particularly prone to settling – the cuprous oxide and other biocides will be at the bottom of the can. For the paint to be as effective as possible these needs to be mixed thoroughly and evenly with the paint.
If you are like me you are probably eager to get on with job of painting and not stirring the paint enough. You should be stirring the paint for 5 to 10 minutes before applying it – an absolute eternity. A good shake of the can and a couple of stirs with a spatula is not enough. Here is how to properly mix your antifoul
- Open your tin of new antifoul and pour half the paint into a clean empty container and put is aside.
- Mix up the stuff that has settled at the bottom of the tin thoroughly. Break up any lumps. A 1 ½ inches wide paddle is ideal.
- Stir slowly using a figure of 8 motion.
- Continue stirring using a beating and lifting motion.
- Continue stirring whilst slowly returning the poured-off portion to the original container.
- Stir some more…
- “Box the paint” - i.e. pour it back and forth from one container to the other several times
The mixed paint should be completely smooth with no lumps of undispersed solids.
This thorough mixing although tedious can be the equivalent of earning $500 an hour as it can make a comparatively cheap antifoul outperform an hastily prepared top dollar brand…