Material choice

Making a metal countertop has long been on my list of things to try when time permitted. Originally, I was drawn to steel with its industrial look, but I had concerns about runaway rust in a wet and humid bathroom environment. I wandered into my neighbourhood metal supplier to see what was available in a gauge thin enough for me to work with and thick enough to be dent resistant. A 19-gauge copper sheeting, sold by the square foot, seemed a very likely candidate; 19 gauge is less than 1/16″ (16-gauge = 1/16″) but still thick enough to not dent easily. Copper is rather expensive but certainly within the realm of reasonable for a highend DIY countertop project. The copper for this project cost $275 (+$90 for the backsplash), and remaining materials were relatively inexpensive.

I did a little reading up on copper as a countertop material before I committed myself. Copper is rather soft and will scratch. It will develop a patina over time, as the colour will change with the application of liquids, chemicals or oils. Copper hit my natural materials preference spot on, but be aware that some people would rather their countertop did not change with time. As a bonus, copper is antibacterial (if unsealed).

Make the copper countertop base

Since I had picked a surface material, I still needed a sink and faucet to finalize my design. I choose a stainless steel sink over ceramic because I thought it would contrast nicely with the copper. Additionally, metal sinks have a lip that can be installed between the plywood and copper so that the weight of a full sink of water is hung on the plywood and not just suspended from the copper sheeting by adhesive. Depending on the thickness of the metal, the weight of the sink could deform the countertop surface over time.

These days, sinks come with templates that give you all the options for layout and faucet placement. My finished drawing contained basin and faucet placement, accounted for the thickness of the backsplash, and included top view plans for cabinetry. Typically, the countertop template is made after the cabinets are already installed, but due to space constraints in this bathroom, the countertop dictated the cabinet shapes.

You will need two different 1/4″ plywood templates. The first template is full sized for the copper laminate. The second template is for the countertop substrate (a double layer of 3/4″ spruce plywood, construction grade), which should be cut back approximately 1/4″ to allow for a finished wood edging. Glue and screw the 3/4″ plywood together. This will be the main thickness of the countertop. I did not have any cherry appropriate for a bent horizontal edging, so I milled up some short lengths of cherry to 1/4″ thick and used masking tape to glue pieces to the edge in a vertical fashion. I used my stationary belt sander to angle and fit the pieces one by one around the curves. After cutting the rough hole for the sink (according to the template that came with your basin), set the sink in and trace around the edge of the lip. This is where the plywood must be relieved to allow the sink to sit flush with the plywood surface.

Cut the copper

I had a friend rough cut the copper with a plasma torch but have since discovered that a jigsaw with metal blade is easier and less problematic. At this point, it did not appear that this shiny, much-scratched, heat-burned piece of rough-cut copper would ever be pretty . Here, the rough edge of the copper is the same size as the base below, and the hardwood edging is also still rough. The front edge will be machined after glue-up, but the sink hole must be perfect and sanded prior to glue-up. I made a rudimentary circle jig for my router and slowly cut the sink hole to size. My personal preference was to make the sink hole about 1/8″ smaller than the manufacturer called for, to have a bit of an overhang on the sink. Sand the sink hole edge by hand or with a palm sander prior to glue-up, as the sink may be damaged when sanding afterward.

Test the fit and glue up

Once the sink has been fit flush into the plywood base, the copper countertop can be test fit. If you are satisfied with how the finished sink hole and sink line up and the other edges look roughly flush, you are ready to glue up. I used Surebond SB-190 Everseal for the glue, but silicone would probably work great too. Clean the back of the copper with solvent, and rough it up by sanding. Set the sink into the plywood on a generous bead of silicone. Smooth a fairly even layer of silicone over the surface of the plywood and over the lip of the sink and apply the copper sheet. Use squeeze clamps, clamps and cauls as necessary to coax into position. The 19-gauge is thick enough to not require hard and perfectly even clamping as veneer would. Clean up any squeeze-out, especially around the sink. Leave overnight to set up.

Shape and sand the copper countertop

After years of practice, I am very good with a belt sander and am quite comfortable using it to shape the edges of a countertop (checking regularly with a square). A more precise method would be to make a router guide template.

Now would be a good time to cut the hole for the faucet. A 1-3/8″ hole saw is typical for this purpose, although a pilot hole and jigsaw works in a pinch.

Once the copper countertop edge is shaped, sand the edging as is your preference. I used a random-orbital and palm sander for both the edging and copper top. Sand the copper until it is quite uniform in appearance and soften the front and side edges. Varnish the cherry edge and underside of the counter prior to creating the copper patina, but try to avoid touching the copper after it is sanded as it is easily marked.

Create a patina

On the freshly sanded copper surface, start by wiping away any copper dust and residual oils with solvent. Create a patina by splashing on vinegar and salt and letting it dry. I made multiple applications over a few days until I was happy with the results. I especially liked the effect of sprinkling cheesecloth with vinegar to create bits of random pattern. Play around with your offcuts to find a patina you like. The blue dust created by this process should not be inhaled, so it is very important to wash down the surface with clean water and a soft cloth until the residue has been washed away. Lightly rub out the surface with 0000 steel wool. An occasional application of beeswax and oil keeps the finished surface from changing too much with use, but it will evolve further over time, especially with harsh cleaning chemicals. Install your cabinets to the sink centreline and scribe and fit the countertop to the wall. Attach the countertop to the cabinets with screws from underneath.

Tips on fitting round doors

As I was working on the countertop, I was also building the somewhat simple cabinets to support it. I went with a bank of drawers and a pair of curved doors below my sink, but your requirements will likely be much different from mine. I did find the curved doors added a lot to the overall appearance, and they weren’t overly hard to create, so I will share some tips on how to make them here.

By measuring my initial top view drawing, I found that I could get away with shaping the front of 8/4 material for the doors rather than a bent lamination or coopering. Loose pin butt hinges allow for mounting and dismounting the doors multiple times during fitting.

After milling the cherry roughly to size and cutting to final height, set a sliding T-bevel from the drawing and mark the angle on the centre edge of each door.  Stand the doors together on top of the drafting to mark the hinge edge angles. Make the doors slightly larger than finished so that the centre edges can be adjusted once the doors are hung. Use a stress curve to mark the bottom of the doors and chisel out material to accommodate the cabinet bottom, rather than curving the entire inside faces of the doors. Relieve for the sink, if required.

Once the doors are fit, use a stress curve to transfer the curve from the drawing to the top and bottom of the doors. Curve the fronts using a handheld power planer, hand planes and belt sander. To keep the fronts true, I made a jig to hold the doors in position for final smoothing with a random orbital sander. Confirm the fit one last time before varnishing.

Copper is a durable countertop surface that adds warmth and character, is relatively easy for a woodworker or DIY enthusiast to work with and is a satisfying alternative to commercially available countertop materials.