Log cabins were a practical way for early settlers to build homes with few tools and lots of trees, but the inevitable spaces between the log required something to fill them. The following instructions describe how to chink and daub a log cabin in a common traditional way, by filling the spaces with pieces of wood and a mortar of local clay, lime and a binder such as straw. A log cabin that's chinked and daubed this way can last for several years without maintenance, but isn't as practical or durable as the many modern chinking solutions available for modern log cabins. However, it's great for a historic restoration, or just as a chance to teach or learn a seldom-used traditional craft.
Fill the spaces between the logs with small pieces of wood, as large as will fit. Chips and slices of wood left from felling and hewing the logs were traditionally easy to find and use, and you can also split up more short chunks of wood or even use stones or twigs. This chinking should fill the space as much as possible, while still leaving room for mortar to be pushed into the cracks.
Gather materials for the daubing or mortar. One traditional recipe consisted of clay subsoil mixed with lime. If you live where there's clay soil, scrape off the topsoil and dig up some bucketfuls of the clay subsoil. You'll also need a bag of lime, available at an agricultural or garden store, and a bale of straw. It's best to do the daubing on a cool overcast summer day, so it won't dry too fast.
Put on heavy-duty rubber gloves. In a large tub or bucket, combine a shovelful of lime with a couple shovelfuls of clay, and add a little water, mixing and gradually adding water until it's the consistency of mud.
Take a handful of straw and mix it with some of the lime-clay mixture, kneading it together until the straw is thoroughly mixed it. Poke this wad of mud and straw into the cracks between the logs, pushing it as far into the spaces of chinking as you can. When it dries, you want it to be wedged into the cracks of the chinking so it won't fall out. Continue covering the chinking with daubing and straw, inside and out, pushing it deep enough so the inside and outside daubing touches in the middle of the logs. Let the logs stick out a little further than the daubing, to protect the daubing from rain. Smooth the outer surface with your hands or a trowel.