2 track tunnel - Straight with 62mm intertrack

Finishing of bioPLA tunnels

Tunnel H0 finish
The tunnel is supplied in a single piece, it does not require assembly. It can be assembled to the portal or to other items of the same type. Use cyanoacrylate glue for fast and resistant fixing.

Surface preparation
Give it a light sanding with 180/240 grit sandpaper and possibly a second pass with a finer grit. With the piece clean and dry, you can use a spray putty to even out the surface and eliminate streaks from the print.
Alternatively, a light layer of plaster and vinyl glue can be applied to the inside of the tunnel. To be sanded once dry.

Painting
Painting can be done with opaque acrylic colours. A dark gray color is recommended.
Subsequent passes can be carried out with various highlighting techniques to highlight flows of water and moss in order to dirty and make the painting less uniform.