Large D&D Table Top Overlay

When we first started our D&D campaign, we were trying to fit our entire party of 6 (plus the DM) around our dining room table with a card table to add extra space. This worked OK until the battle maps came out, then we had to move all our notebooks, snacks & drinks, etc. to make space to kill the bad guys and loot the bodies. After a few sessions of doing this, I asked if everyone would be interested in chipping in to buy the materials so I could make a larger table top that would sit on top of our dining room table.

Supplies

2 sheets 3/4" sanded plywood

4 Threaded inserts

4 Bolts

4 Sash locks

Stain

Small foam brush

Polyurethane

5 minute epoxy

Misc scrap wood

Circular saw

Jig saw

Belt sander

Drill and bits

Utility knife

Biscuit joiner & biscuits

Router and round over bit

Step 1: Design

Our dining room table is roughly 5' x 3'. I wanted to end up with a table top that had enough space for each party member to have roughly 2' of table space plus 3' for the DM at the head of the table. I used Sketchup to layout the size of the table and the campaign maps, then added in the overall size and shape of the table. Yes, the sketch is hard to make sense of, but I highlighted the essential information so that I would be able to transfer it to my plywood. Since the table top would be symmetrical along the center line, I didn't feel the need to put all the details on both sides. As shown in the 3rd picture, the curve at the bottom of the table (highlighted yellow) has a radius from the center of the table. The long side curve (pink highlighted edge) is just a faired curve that I did manually and that just looked good to me.

Step 2: Cutting the Pieces & Putting It Together

Based on the design, the new table top ended up being a little over 6'6" long and 4'8" at its widest point. I ripped the sheets of plywood to 2'5" (a little over half the width of the final table width) wide and transferred one half my design to one sheet.

The curve at the bottom of the table is based on a radius from the center point of the table. The center of the circle for this curve would be on the center line of the table, so I clamped a small jig I made using a nail for a pivot point and drew the curve at the appropriate radius.

To draw the long curve along the side, I placed a screw in the plywood at each end of the curve and marked the distance out from the center line. Then placed a long, thin strip of wood against each screw and flexed it out to the center mark and traced along the curve.

After seeing the layout full size, I decided to not trace a curve for the head of the table and just left that edge straight for the DM to sit at.

After I checked the overall shape of this half of the table, I cut out the shape with a jig saw being careful to not get too close to the lines. Next I laid the first piece on top of the other half, traced the shape and cut out the 2nd piece. I clamped both pieces together and used the belt sander to sand up to my original layout lines and smooth the edges. Clamping the two pieces together for sanding keeps them symmetrical. I rounded over the edges with a 1/4" round over bit in my router to soften top and bottom edges. Finally, I cut each long side in half for ease of storage.

On the bottom of the sections, I marked locations that I wanted to install biscuits to align and hold the sections level when the table top is in use. I cut the slots on each section and then glued biscuits into one side of each seam. I installed a sash lock at each seam between the sections, making sure that they were outside of the perimeter of the dining room table.

Threaded inserts were installed into the bottom of the sections. I put one at each seam between sections. They can be on either side of the seam. I made clamp blocks from wood scraps. The knob to tighten the clamp block was made by gluing a bolt into another scrap of wood using epoxy. Sand and finish these to whatever shape you like and that works with your table. Obviously, the clamps lock this tabletop onto the base table, but since this top overhangs the base a lot, they also serve to keep the sections from flexing when someone leans on it

At this point, you could finish the sections however you want and you'd have a functional oversize table top to seat your party. However,...

Step 3: Adding the Artwork

As part of my build, I wanted to make this tabletop D&D themed. I did a quick search for "free dragon head image" and found this black and white picture. I wanted something symmetrical and without too much detail. I wanted to enlarge my dragon image from 5-1/2" wide to roughly 29" wide. To transfer the image to the table top and enlarge it, I used the "grid" method. If you aren't familiar with this method, here is a link to a video that shows this method very nicely -

Since my chosen image has so much black, I drew the grid on the back of the print of my image so that I'd be able to see the lines. It was easy to see the actual image through the paper with a little bit of back lighting. I drew my image and grid lines very faintly so that I wouldn't need to work very hard to clean off the pencil lines later.

Once the image was transferred, I used a utility knife to trace the image and cut through the wood fibers on the top layer of the plywood. This is especially important so when applying the stain it doesn't bleed into adjacent areas and you get a nice, crisp image.

Using a small stain brush, start filling in the image. Don't use very much stain, especially in small or tight areas, or the stain will still bleed across the tracing lines! I used Minwax stains. Colors I used are: Gunstock for the main body of color, Golden oak for the accents, and Ebony for the details around the eyes. The whites of the eyes are the natural wood color. I really debated whether I should do a background color or not, and finally decided that I would use Early American as the stain color for the background. Once the stain was dried, I applied several coats of polyurethane to seal and protect the wood against scuffs and spills.