Assembling the raw materials for a beer-cap coffee table is the easy part. Flip the caps off your favorite brew, taking care not to bend them. Once you've collected enough caps to pave the top of an old coffee table, experiment with designs and fill in any style or color gaps in your collection. Then find a well-ventilated, protected spot to brew a very sturdy, if time-consuming, bottle-cap tabletop. When it's complete, you can set frosty cans, bottles and mugs right on the table without worrying about leaving rings or damaging the finish.
Clean off an old wood coffee table in need of a makeover and refinish or paint everything but the top surface. If you are stripping old paint or varnish and stain, do that for the tabletop as well but don't yet re-stain or paint it.
Cut four narrow pieces of molding to frame the top of the table -- they should make a frame slightly higher than the height of the bottle caps. Miter the molding ends at a 45-degree angle to create snug corner connections. Brush wood glue on the bottom of each piece of molding and on each corner joint, and nail the molding to the table. Paint or finish the tabletop and molding to match the table.
Arrange the beer caps, top-side-up, on the top of the table inside the molding frame, to cover the entire surface. Make a design, create an ombre-style graduated color pattern, or just scatter the caps randomly. Glue the caps to the table surface so they won't shift when you pour the resin over them. Let the glue dry.
Flood the tabletop with a 1/8-inch-deep coat of two-part self-leveling epoxy resin. Follow the manufacturer's instructions for mixing the two liquids, then pour the mix on the bottle caps. If bubbles appear in the resin from air trapped under the caps, point a hair dryer or a kitchen torch at that spot on the table to heat the resin, and the bubbles will disappear.
Pour the rest of the resin to fill the molding frame around the bottle caps and completely submerge them in clear resin, once the first resin pour is on the table and the caps are stable. Bubbles may continue to appear for a while, so monitor the project carefully and heat any bubbles to get rid of them and make your tabletop as smooth as glass.
Let the resin harden in a dust-free work space before using the table.
Use a wood tongue depressor to push any "floating" bottle caps back into place on the first resin pour, if any glued-down caps become loose.
Don't worry about smoothing the resin, as it levels itself. But do place your table on a level surface when pouring the resin and allowing it to set up.
If your bottle-cap collection is growing too slowly, visit local breweries and flea markets for large lots of pristine beer bottle caps.
Always work with strippers, stains, finishes and resins in a well-ventilated space. Use a painter's respirator mask for extra air filtering.