Spraying Epoxy River Boards

Epoxy resin projects seem to all the rage lately, and I must admit they are pretty satisfying to build.

If you aren’t ready to commit to a large-scale river table, consider a river board or coasters.  These small projects serve as a great introduction to the world of epoxy.

I like to make river boards about 20” long x 10” wide and about an inch thick.  Sometimes the live edge boards you have available will dictate the size of the project.  Another common size I’ll make is 16” long x 12” wide serving boards.  Ultimately, it’s convenient if the project will fit through your planer.  If you size the project for the planer you have available, it’ll save a lot of extra work in the milling and sanding phases.

Coasters are another fun project, and depending on your design, might not even require live edge boards.  I usually make coasters 4” x 4” and plow one or more grooves that can be filled with colored epoxy.

But what finish is appropriate for epoxy boards?  I have experimented with this topic, and discovered that a sprayed lacquer topcoat works well for projects containing both wood and epoxy.  Before applying the sprayed topcoat, I like to apply a Danish oil.  This brings the grain to life and is a great first step towards a beautiful finish.  One important thing to note is oils won’t readily penetrate the epoxy surface.  The oil does make the epoxy shine, and is a good preview to the final look of the project.  However, since the oil doesn’t penetrate the epoxy, you must wipe off any excess oil.  I do this step twice with a clean, lint-free rag.  Once after wiping the oil on, and again a few hours later to remove any residue.  Ultimately, you’ll want to let the oil dry for 24-48 hours depending on temperature and humidity.

With walnut boards, you’ll notice a more dramatic effect from the Danish oil.  Walnut tends to darken substantially when oil is applied.  Expect the intensity of the color to fade as the oil dries.  Don’t worry though, the beautiful colors of the brown walnut and Caribbean blue mica will return once we spray the lacquer topcoat.  In this example, instead of live edge boards, simple grooves were milled to create channels for the epoxy.  Even the large knot is fair game for filling with colored epoxy.  In fact, working with epoxy makes you want to celebrate the “defects” in lumber, rather than discarding them.

Coasters use the same approach – two milled channels make room for the colored epoxy.  Placing the grooves off-center adds a stylish touch, and allows you to highlight spaulted or figured grain, or the occasional knot.  In batching out dozens of these little coasters, I realized the ones with color filled knots quickly became my favorites.  Experiment with different mica colors of your choice, but Caribbean blue, Deep Blue, Black and Emerald Green tend to be the most popular.
Prepare a large work area with brown craft paper to keep your bench clean, as well as painter’s points.  You can use commercially available products, but I quickly ran out, so I made some screw blocks.  These are just a variety of wooden blocks or strips of plywood with drywall screws driven in from underneath.  The great benefit to using screw blocks, especially when spray finishing, is you can finish both sides at once.

To spray lacquer, I select the 1.4mm needle and nozzle set on my Fuji LX-20 HVLP high performance spray gun.  I find this size set allows for the best spray pattern for lacquer that has been thinned slightly.  I typically thin my lacquer with 10% lacquer thinner by volume.  My number one rule when filling the LX-20 is to FILTER EVERYTHING THAT GOES INTO THE FLUID CUP.  Even when pouring clean lacquer thinner into the cup, I’m always sure to have a filter strainer in place.  Even new metal containers can have contaminants in the can like bits of rust.  So many problems in spray finishing can be prevented before they even start with this simple rule.

A high performance HVLP gun like the Fuji LX-20 is an important tool in the woodworking shop.  Many magazine articles recommend wiping on a topcoat.  Perhaps to appeal to the novice woodworkers who might initially be intimidated by spray finishing.  I am certain of one thing though, once a woodworker tries spray finishing with a quality gun, they can never go back to wipe-on topcoats.  With high transfer rates and a finish second-to-none, a sprayed finish is the way to go.  In fact, my second coat with the LX-20 is usually perfectly smooth right off the gun, with no scuff sanding required.

Here the LX-20 is halfway done with the first coat on this deep blue “Ocean Board.”  A great off-the-gun finish has always been a hallmark of a professional spray gun.  If you’re ready to step up your spray finishing game, check out the LX-20 HVLP high performance spray gun.

THE AUTHOR

pintodeluxe@aol.com

Willie Sandry is a Freelance Writer for several woodworking magazines, professional tool tester, and spraying enthusiast. Find his latest projects and reviews on his YouTube channel at The Thoughtful Woodworker!

Fuji Spray Systems®

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