Some hard fillers, like traditional polyester resin–based builder’s bog, have no flex, so they don’t last long in exterior applications where wood expands and contracts. Striking the right balance between the bulk needed for larger holes and ease of handling, stability, and flexibility has given rise to a broad range of fillers available today. Phil says, being acrylic based, Selleys Permafilla is flexible but also tough enough to be used indoors and out on timber, brick, concrete, stone, and even primed metal. It can be sanded, painted, drilled into, and even nailed. For small cracks or dents he recommends the Spakfilla range. It features a micro-balloon construction, which makes it rapid drying and much more sandable than the tougher Permafilla range. It also sticks well to paint, so he recommends…
