HOW TO: APPLY SURFACE FINISH TO WOOD
Updated: Apr 12, 2019
I love a great DIY wood project for your home but if you want to ensure your piece stays durable, long lasting and appear richer, than a good wood finish such as a shellac or varnish is a MUST!
This article outlines my two favorite finish types and a quick breakdown on how to apply a finish, so that your next DIY project will have a beautiful professional look too.
Both a shellac and varnish should be applied with brushes and will dry on top of the wood to create a protective coating.
Oil-based finish (shellac)- apply with a natural brush or a synthetic one with a tapered end and strong bristles.
Water-based finishes (Polyurethane)- apply with a synthetic brush with a tapered end and strong bristles
Avoid cheap foam brushes, as they tend to wear out quickly and don't provide a smooth coat.
** NOTE: Try pulling gently on the bristles to ensure that they're well attached. Poorly made brushes may shed bristles into the finish. You don’t need to invest in the super expensive brush, but I do recommend investing in a medium quality one to protect your project.
Shellac: is a quick-drying surface finish. This finish is a natural product (it's made from combining a secretion from the female lac bug with a solvent such as alcohol) and is considered a safe option once dried and hardened. Shellacs add a warm amber color to the wood, so keep this in mind when trying to determine the finished look of your project.
** NOTE: A shellac can be heavily affected by heat and chemicals. If you leave a hot drink or bowl on its surface, a white ring could appear. Basically, If using this finish type - avoid furniture types such as a kitchen table or coffee table, unless you’re really good at using coasters.
Varnish: The best and most durable Varnish is polyurethane (my personal fav). Polyurethane is available in both water and oil-based options, and comes in many varieties from satin to glossy. For me, it’s the most affordable option and easiest to work with.
What I like about the water-based polyurethane is its low odor and low toxicity. It goes on clear without adding any tinting that oil-based versions can create, and it dries much faster! #WIN
Keep in mind, as with shellac, water-based polyurethane won't hold up well to heat and chemicals.
STEP 1: Before applying your finish, make sure you wipe off the surface of your project with a tack cloth. A tack cloth is a sticky cheese cloth that’s great for picking up any leftover material and dust that still may reside on the piece.
STEP 2: Stir the varnish in a figure-8 pattern. Never shake varnish, as that may produce bubbles that can dry into the surface of your project - you don’t want that.
STEP 3: To minimize runs and drips, brush from the middle of the board, working toward the edges. Smooth out any of those troublesome bubbles by holding the brush at a 45-degree angle and gently, pulling the brush in long strokes to the entire length of the board.
After the first coat is completed, let it dry.
** At this point, you will be impatient and want to dab, fix or add more finish. DON’T. Wait for it to dry!
To prevent your brush from drying out between coats, you can clean it, store it in a jar of mineral spirits, or go the more DIY route and seal the entire brush in a zipper-top plastic bag and store it in the freezer.
STEP 4: The first coat of finish you apply will be absorbed into the wood, filling most of the pores in the wood's surface. The second coat won't have as much to cling onto. To help the second coat stick to the first, use a 220-grit sandpaper to rough up the hardened first coat. This technique is called “scuff sanding”.
Again, using a tack cloth, wipe off any dust created by sanding. Then apply the second coat of varnish in the same manner as the first.
STEP 5: Repeat the same sanding/cleaning/Varnish steps for one -two more coats, each time using a higher grit sandpaper from the last. For example, after the 220, I would move onto a 300-grit paper. The idea is to move your way up the grits until you’re happy with the smoothness of the finish applied. Two - three layers usually will do the trick, but you can apply as many layers as your like. The more coats you add, the more durable the project will be!
So now that you got the know-how, you need a good project to apply it!
Check out these DIY projects where I use a nice finish to make my project look professional!