Approach the creation of a coffee table with a topping of pebbles or a design formed with pebbles as a mosaic project. A mosaic is an image formed with small bits of stone, tile, glass or other objects. Use pebbles to completely cover a coffee table top in random order. Alternatively, achieve a design by affixing pebbles one at a time. Pebble-covered coffee tables can be made for indoor or outdoor use.
Pebble topped coffee tables are heavy, so make sure the table is sturdy. Proper preparation of the coffee table is important for a successful project. Seal the pebbles with a grout sealant according to the sealant's directions. Home improvement and building supply stores sell grout and tile sealants and products that enhance the natural hues of pebbles. There are more steps if you are affixing the pebbles onto the tabletop in a design. Choose or create a design and draw it onto the table with a permanent marker or oil pencil if you will be applying pebbles with epoxy. If you are using thinset (a type of cement) the table top will be coated, so draw your design on clear cellophane plastic to be held above the table as a guide for pebble placement. Purchase plexiglass, acrylic plastic or glass cut to the measurements of the table top to place on top of the pebbles if you want a smooth top when finished.
Thinset is a cement mortar that must be used for outdoor pebble-covered coffee tables. Thinset is available at home improvement or building supply stores. Indoor tables also benefit from a thinset pebble application. Mix about 0.907 Kilogram of thinset according to the instructions and spread it onto the table top with a trowel to a 1/4-to 1/2-inch thickness (depending on the size of the pebbles). Insert pebbles into the thinset so the thinset doesn't slop over the pebble tops. Space pebbles no more than 1/8-inch apart. Wipe the thinset from the tops of the pebbles with a damp rag. If you're covering the top randomly, press the pebbles in columns until the table top is covered. If you're following a design, have an assistant hold the plastic above the table and work between the thinset-covered table top and the plastic. Place pebbles one at a time into the thinset. Allow the thinset to dry according to the duration specified by the manufacturer.
Epoxy or Super Strength Adhesives
Epoxy adhesives typically involve two or more solutions that must be mixed together to activate the adhesive. If you're using a super-strength adhesive, use one that is thick and tacky, not watery or oily. Adhesives are the best choice if you're placing the pebbles in a design onto the coffee table. Spread or squirt the glue onto the appropriate area of the design and press a pebble into the adhesive. Space the pebbles no more than 1/8-inch apart. Allow the adhesive to dry for at about 48 hours.
Grouting the Pebbles
Once the thinset or adhesive has dried for the duration recommended by the manufacturer, it is time to grout the pebbles. Grout fills the crevices between the pebbles. Use a household mist bottle to spray the pebbles with water. Wipe away or use a razor blade to gently scrape away any thinset or adhesive on any pebble tops. Prepare grout according to the manufacturer's instructions. Use a putty knife to smash the grout over and between the pebbles. Wipe the wet grout away with a wet sponge so there is no grout on top of the pebbles. Coloured grout is available if desired. Allow the grout to dry for at least 48 hours (more if recommended by manufacturer). Use a grout-and-tile sealant to seal the finished table top.