Firstly it’s important to note that ready to use fillers obviously do not need mixing with water!  This is because their consistency has already been finely adapted by the factory for their intended use. This makes ready mixed fillers a good choice for jobs at locations where running water might not be available.

Mixing Power Fillers

On the contrary when using powder fillers, mixing with clean water is essential. Generally they require a ratio of about two parts filler to one part water, but always check the manufacturers instructions. This is because the target consistency might vary depending on the fillers intended use. For example professional decorators may choose to blend a looser or tighter mix.

Measure roughly the amount needed into a mixing container and form a volcano shape with your filling knife. This will create a cup for the water to be poured into, helping to ensure that you don’t add too much water. Gradually add water to the filler turning over the mix to ensure the liquid gets evenly dispersed.

Continue mixing together until you have a nice creamy consistency which allows you to build peaks without collapsing. You may need to add a bit more power or water to acheive this.

Beware of Limited Filler Working Times

Once they have been mixed, powder fillers have a limited working time, after which they can no longer be used. Depending on the product this window varies between about thirty minutes and several hours. So beforehand always consider how much you will be able use within this time frame before mixing any filler.