I get the Oak boards as they are imported from France, either 19mm or 27mm thick, Rough Sawn, still with the watermarks on, presumably from being Kiln Dried.
I then cut into the widths I need and put them through the thicknesser
To be honest I didn't try other woods, but will do now thanks and I did use a PTFE spray on the feed beds, but have cleaned them twice now with a white paper towel and didn't see black marks or residue.
I have recently purchased a Makita 2012NB Thicknesser, its a great piece of kit, but I am getting thin black lines on the underside of the planks I put through.
The wood is Oak and I have cleaned the surface of the base plates and find it baffling that the marks are on the underside.
I could...