How To Clean Sap & Resin from Wood
Wood surfaces, both indoor and outdoor, can be vulnerable to the sticky spots caused by sap and other resins. Outdoor decking can get repeatedly stained through environmental exposure, while indoor furniture is more likely to be subject to seasonal stains like those from a christmas tree. In any event, there are a couple of effective methods that can be used to soften and aid removal of these sticky spots. Keep in mind that wood types and surface finishes can vary widely so even the simplest methods should be tested prior to use in a wider area. Testing should include any standing or waiting times described in the cleaning techniques.
Waterless hand cleaner is a relatively benign product that is widely available, and can be used to work on a wide variety of staining materials. Apply a non-abrasive waterless hand cleaner, between 1 tsp and 1 TB depending on the size of the spot, to a clean cotton ball. Place the cotton ball, waterless hand cleaner side down, directly onto the spot with gentle, firm pressure. Allow to sit for 15 - 20 minutes. Use a clean rag to remove any waterless hand cleaner residue, Use a dull-edged scraper or similar to remove the bulk of the softened spot. Use a clean area of the rag, dampened with hot water, to work on any remaining residue.
Some varieties of waterless hand cleaner include pumice or other abrasives - these ingredients boost effectiveness for scrubbing away sticky residue. If you have a particularly stubborn sap or resin stain, and are not concerned about abrasion marks (either because the area is already well marked, or because you are cleaning the wood surface in preparation for refinishing), you can use waterless hand cleaner applied with a clean rag and a rubbing motion with the grain to work on sticky stains. Always make sure to rinse and remove any resultant residue, and allow the area to dry thoroughly after spot removal.
A stronger solvent may be necessary for extremely resistant stains. Turpentine, applied with a clean rag, can be applied to help soften sap and resin drops. Turpentine fumes can be hazardous and flammable, and manufacturer's warnings and recommendations should be followed.
If the spotting has been extensive, you may want to consider conditioning and resealing the wood surface with the recommended commercial product (for indoor furniture, cabinetry, outdoor deck planks, etc).
Caution: Never mix cleaning agents or chemicals, the result can be dangerous or deadly. Before cleaning, always test the agent on an inconspicuous location to determine its suitability and to make certain it does not damage the material. Wear appropriate clothing such as gloves and protective eyewear, and work in a well-ventilated area. Accidental inhalation or ingestion of cleaning agents can be hazardous and even fatal, particularly to pets and children.