Sap is a tree’s lifeblood; it includes the essential nutrition from the roots out to the ends of the leaves and branches. When timber is cut from the tree, the sap no longer runs as it did at the wood. Lumber that has been kiln dried has had the sap heated to crystallization. From time to time, changes in humidity or temperature might lead to cut boards to ooze sap. There are several ways to remove the sap.
Removing Fresh Sap
Fresh, oozing sap is a really sticky substance which can be difficult to remove. Use a thin metal scraper to remove as much of the sap as possible from the surface. Use oil soap to remove the sap residue. Apply the oil soap with a soft brush, undiluted, and wash the surface nicely. Rinse the region with warm water to complete the removal procedure. Use acetone to remove any remaining residue from the timber.
Removing Hardened Sap
Allow the sap to set till it hardens completely so that the surface is hard and dry, without tackiness. Position a very sharp wood chisel using the bevel border facing upward, and the flat side of the blade against the face of the wood. Press the edge of the chisel under one border of the sap until it pops loose from the stair surface. Use acetone to remove any residue from the surface.
Kilns crystallize sap in the wood by heating it up over 140 degrees Fahrenheit. You can use the exact same effect to your advantage with a handheld heat gun. Plug into a heat gun and set it on the highest setting. Aim the gun at the oozing area. Keep the gun moving to prevent scorching. Keep the gun concentrated on the region for at least five minutes, moving it slowly, letting the wood to warm thoroughly. This might cause the sap to ooze initially, then harden. Remove any sap from the surface using a chisel and remove the residue with acetone. The inside sap will crystallize and harden into a rocklike deposit. Unless temperatures reach over 140 degrees Fahrenheit, you should not see oozing from this spot again.
Sand the wood surface with fine 220-grit sandpaper to smooth the grain and then remove any crystallized sap. Sanding blocks help sleek big, flat places. Use a Handheld oscillating, fitted with 240-grit sand paper, for edging and corners. Wipe the dust from the surface using a tack cloth. Apply a coating of stain and clear finish a coat of fitting semigloss latex paint. Use a paintbrush to apply the fitting finish smoothly. Allow the first coat of finish to dry thoroughly. Apply a second coat, and a third coating if desired to match the original finish.