This is a great question and is often case-specific. Most of the time we do recommend thinning pure tung oil with a solvent. This is to aid its absorption into the wood. New woods and hardwoods almost always need pure tung oil to be thinned. Very dry old woods, end grain, or some softwoods can use pure tung oil at full strength without thinning. We always recommend testing to ensure the proper absorption. Click here to view a useful graphic to help you determine if your wood requires thinning the pure tung oil.
