I am trying to finish a wooden floor (pine), colouring it with stain. After that it shall be oiled.
The process for usual painting with paints has usually been that you sand it, then apply filler, then sand again, then paint, then varnish.
Now in this case I tried to do the same process, except with stain and oil, but it turns out that when I apply stain , it will create large blotches of different tone, where it is overlaid on filler. Obviously one should remove filler as much as possible during the second sanding, however, as it is virtually invisible after drying, it is hard to judge when it is removed enough.
It is quite ok if the filler will create different tone in the gaps between the floorboards, but there are patches of it smeared a across half the board width every now and then.
Is there anything I can do beside trying to remove as much filler as possible during the process?