Paul recommends 2 methods to sharpen an out-cannel gouge which can both be done on diamond plates or abrasive paper. You will also need a curved strop, which you can make yourself, to polish at the end of the sharpening process, for this you will need a concave one and a convex one (to polish both the inside and outside of the bevel).
Figure of 8 Method:
To use the figure of 8 motion, start at the bottom left corner, use the corner of the gouge as your starting point at 30-35°. Push forward and roll the bevelled edge from one corner to another until you reach the top right corner of the sharpening stone, move across to the top left. Keeping the bevel in contact with the sharpening stone, move backwards, roll the bevel back round to end up at the bottom right corner.
Rotational Sharpening Gallery:
An alternative sharpening method is rotational sharpening. For this method you do not use a figure of eight motion but instead, use a straight back and forth motion to sharpen the edge, rolling the bevel from corner to corner as you go.
Repeat steps on the fine plate, abrade until coarse marks have been removed, then super fine, this creates a camber on the edge which works well for carving.
To read more on a gouge, we recommend the following from Paul’s blog: