A next generation lightweight interior and exterior filler based on acrylic polymer and hollow ceramic microspheres robust macromolecular structure which gives virtually no shrinkage filling deep holes without sagging isnt easy but with ronseal bhf12l big hole smooth finish filler it is specially designed to fill any hole up to 50mm deep its a high performance filler thats easy to apply and gives a perfectly smooth finish when dry it can be drilled screwed or nailed for use in repairing plaster