I’m on the board of my county historical society. We have an 1867 log cabin. It has been suggested that we use linseed oil on the exterior and portland cement.for chinking and daubing. I think we need a second opinion. Would linseed oil and portlandcement be appropriate?
The Portland is historically correct, but does not work well. It will dry and pull away from the logs leaving a small crack for water to get in behind it causing rot.
Not sure how true to time you are trying to be, but Perma Chink makes a latex chinking that looks like Portland and works great.
DO NOT put Linseed Oil on it. It is food for mold and will turn the place black over time. Apply an application of Shell Guard borate to help stop rot and bugs (not carpenter bees) and let it turn gray.
Call 800-564-2987 for the materials and more help.