Best structural filler?
As the title suggests, I'm looking for a structural filler that will hold a screw well. I'm making repairs in timber of surfaces that are required to be screwed into frequently. So far I have tried a few different options:
- sawdust and glue mix: seems so far to prove the best, but is the most time consuming and hard to get consistently right with the ratios.
- epoxy filler: doesn't shrink and is strong but often too brittle for deeper flaws and can shatter when screwed into.
- spakfilla: too weak.
- bog: too brittle
- other products like selleys plastic wood: not bad but not quite as strong and decent amount of shrinkage.
Does anyone have other suggestions or things they've used in the past that have good structural hold and is easy to work with?