The manufacturer states that Timbor will last for the life of the wood as long as the wood is not exposed to rain or flooding. It will stay in the wood forever because of how it bonds to the cells of the wood.
There should not be an issue with the application to the logs after treatment of Tim-bor Professional when used as directed.
Tim-bor Professional can be used on all types of lumber, logs and plywood. Ideally, it's recommended to cut, shape, and sand the wood before making an application of Tim-bor.
Tim-bor Professional should be applied prior to staining the wood. If you stain the wood first, the Tim-bor will not be able to penetrate past the stain & on to the wood. Once the product has dried, you may stain the wood
When treating raw wood for active beetles, it is not recommended to use Timbor Professional. Instead, you should use Boracare which penetrates deeper into the wood and can be used for active problems vs just preventative like the Timbor is designed to do. That being said, even if Boracare was used, you would still see signs of powder post beetles after treatment. This is normal and expected since the eggs/larvae can lay dormant in the wood for years. The signs you are seeing of dust and holes are the ones that have progressed into an adult beetle and are eating their way out of the wood. As they eat their way out, they are ingesting the borate-treated wood and will die from it, which keeps new infestations or reinfestations from occurring. Seeing signs after treatment does not mean the treatment failed, it simply means those insects are still emerging to be impacted by the chemical. Boracare and Timbor kill through ingestion of the chemical, not through simply contacting a treated surface.
We do not recommend applying Timbor to wood that will be torched. Burning wood treated with any insecticide would release the active ingredients into the air. Burning the wood without treating it with any chemical will kill anything in it.
