"Wood filler is usually sawdust suspended in a hardener (maybe glue or varnish)," he said in his exclusive House Digest interview, noting it is primarily used indoors. "You can DIY wood filler ...
varnish or glue. Some contemporary products, such as DAP’s Plastic Wood All Purpose Wood Filler, combine wood fibers with a solvent-based hardening resin while others combine gypsum, limestone ...