Hello Tone,
You should wait on this idea until you have ran a few hundreds of kilo’s of wood through your system.
Good operating raw wood system will assume an upper hopper thick coating:
page scroll down for the open hopper down picture.
Ha! I am not picking on Joni. I’ve just kept his earmarked.
All others with worked systems do this too. Why many insist on black painting the outsides of theirs to not have to continually clean the black drool streaks.
You will have to position your tubes inlets to not quickly pick up tars smoke and build up layers clog.
Regards
Steve Unruh