Rather than try to fill the hole with bog, I made a fake knot to fill the hole, and then fixed that in place. The first step was to cut a small piece of timber from the same plank. I also removed the loose bark and other material from the hole – note that I didn’t shape the hole in any way – to keep it looking natural.
I placed the blank over the hole and roughly marked the shape (oversize!) with a pencil. Then using a saw, wood file and bastard file the blank was shaped to fit the hole. The process involved cutting/filing a bit, returning to the hole and marking more pencil, then returning to the vice for more cutting and filing. Eventually the new fake knot was almost the right size.
After some final filing the knot fit perfectly into the space left by the loose knot – not too loose and not too tight. The edges of the knot are not vertical – they are sloped at about 30 degrees so be careful to account for this if you are replicating this process.
The fact that there is a little space around the edge of the knot doesn’t matter – it makes it look more authentically like a knot 🙂 The final step was to use wood coloured putty to fill all the gaps around it. On hindsight I should have glued it in place first before using the putty, but I’m hoping the putty will be strong enough to keep the new fake knot in place!
This whole process took maybe 20 minutes.