For those cosmetic joints that are less than 3/8 inches deep, the answer is fairly easy. Unless the log home manufacturer specifies the use of Perma-Chink, Chink Paint is less expensive and much easier to apply, especially if you are planning to do it yourself. Since there is no room for backing material, we have seen several instances when a thin layer of Perma-Chink was applied directly over bare wood and blisters formed in the chinking. Even if the bare wood is covered with masking tape, it may still not be a good idea to use Perma-Chink. If the Perma-Chink only has a 1/4” lip of wood to hold onto on the upper and lower edges, there may not be enough surface area for good adhesion. If Perma-Chink is applied and masking tape is used as a backer in shallow chink joints, it’s especially important to make sure that the tape does not cover any edges. If it does, there will be virtually no adhesion of the Perma-Chink at that point.
Whenever Chink Paint is used and a seam is present within the cosmetic joint, the seam may be first sealed with Energy Seal. Once the Energy Seal is dry, Chink Paint can be applied over it. Do not use masking tape under Chink Paint. It will prevent the Chink Paint from adhering to the wood and may eventually peel off.
For cosmetic chink joints that are 3/8 inches deep, or deeper, Perma-Chink may be used; but you should be aware that Chink Paint is a less expensive alternative that’s much easier to apply. If the joint is deep enough to accommodate both backing material and the proper thickness of Perma-Chink, it’s best to actually chink it to prevent water from accumulating on top of the bottom lip.