How to Clean and Prep Douglas Fir for Staining

Test your Douglas Fir wood for moisture. Stick a piece of household tape firmly against the wood. Tear it away and look at the back of the tape. If old or loose pieces of wood fibers appear, the wood is moist and you must let it air dry before staining it.

Scrape off all pieces of damaged wood. Use a putty knife to scrape off and lift rotted pieces of wood.

Fill in holes and scratches on the wood with wood filler. Use the putty knife to pack in the holes and scratches on the wood. Let the wood filler dry for at least six hours.

Clean the wooden surface. Apply wood cleaner directly to a rag and wipe clean all dust, debris and oils on the wooden surface. Apply more wood cleaner to the rag as the rag becomes dry. Let the wood air dry for at least three hours before applying the stain.