Chinking the inside of the cabin and building the fireplace hearth.
In between the logs there is actually some insulation. It is encased between metal lathe and the chinking compound on both sides. Inside and outside.
I do not have pics of us working on the chinking inside, but you can see how we did it on the outside HERE. It was the same process inside, except we stuffed insulation in between the logs before we nailed the metal lathe up.
(here's a pic of the completed fireplace and chinking)