|
Actually your problem is unhardened sealer and or sap (probably the former with birch) that is driven out of larger pores as the heat expands the moisture in the wood. Even tiny areas that seem innocuous will discolor the epoxy gradually after the plug is done.
You can try heating your sealed plug @ 180 for 20" before priming, let it cool then sand lightly. That will stop most of it. Don't try this unless the sealer is already dried by normal means.
|