In todays world where sap wood is no longer viewed as a defect in most woods it is something you will have to deal with sooner or later. so it is a really good to know how to color it in. it will also help you to be able to tie together the colors of boards and since it is stained it will keep a constant color instead of aging. its just a really good skill to have that you will use a lot.
so the first thing that you want to do is spray the pieces. in this case i used two coats of a general finishes light brown waterbased dye. you don’t have to do this if you feel that you can color in the sapwood to the natural wood but if not this helps a lot. then just with your fluid nozzle and fan width turned down spray some dye onto the sap wood until it just about matches the heart wood. this is to create an even background for the gel stain to accent off of.
next its time for the stain. for coloring in sapwood you want to use a gel stain or a water based stain. these stains are made to stay on top and not soak in so they will accent off of the equalized backround. a regular oil based stain or dye will not work as well because it will soak in and color the
wood instead of accenting off of it. in this case i am using an oil based so it won’t redissolve the dye. if you are using a water based stain you want to spray a 1/2lb or 1lb cut of shellac on the surface wiping it over with 600 grit sand paper to create a mechanical tooth for the water based stain to grab on to. make sure to stay away from edges as you will cut through your finish.
so then just put on a bout 3-4 coats of gel stain and stand back and enjoy your finish, and no one will ever know that there ever was any sapwood in your piece.