Protect Your Logs from Infestation, Mold and Mildew.
If you want to keep your logs preserved for a long time, use borates, the most popular treatment against mold, mildew and infestation.
The exterior pigmented stains that have "preservatives" incorporated in the stain are ineffective. Most biocides added to paints and stains are what are referred to as "in can preservatives". Their function is to prevent molding and spoiling of the contents while it is in the pail and they don't have enough concentration for actual pesticides usage. If they were truly pesticide products they would have to be labeled as such and approved by EPA. If they are not, they do not have enough concentration of biocide to really control any biological activity.
The borates are EPA registered pesticides. They are much safer for the consumer and the environment than a number of other pesticides. The water wettable powders, and the glycol carried products disperse very quickly into the logs. Impel Rods are essentially fused borate rods that look and feel very similar to glass. They are effective, but take a very long time to dissolve and diffuse. Use a glycol carried borate for quicker diffusion.
Important point – glycol carried borates can take up to 2 weeks or more to dry – however depends entirely on wood moisture content and local weather conditions. Logs treated in Colorado in the summer are ready to stain in two days. Hot and dry weather, and dry logs – good to go in two days – cold, damp, and wet logs - could take over two weeks. In any case, test early in the morning before the sun dries out the surface of the logs. If the logs feel damp, and maybe a bit slippery – wait. If the logs are dry and not slippery, you're good to go.