Make your own custom sink-matched cutting board


By Greg Illes

Our RV kitchen came with a small board that filled in part of the sink area. This was handy because the whole sink is not always in use and counter space is at a premium.

After a few outings we found out that our water-savings plan meant that the sink was very rarely in use. We also found out that the filler board (made from countertop material) needed an additional cutting surface to prepare food. Thus began a search for a combination counter/cutting board. We soon found that no such off-the-shelf product exists, much less customized for our Itasca sink. So off to the plastic shop we wandered to buy some HDPE.

“What?” — I hear you cry in great confusion. Ah, Grasshopper, that little acronym stands for High Density PolyEthylene, the gold standard for cutting board material. This stuff doesn’t soak up fluids like wooden boards, it’s easy to clean, very easy to fabricate, and is available in thicknesses from 1/2 inch to 1 inch and greater.

To build one of these, it’s best to make a cardboard template to match the outline of your cutting board. Trim this exactly to where you want the board to fit. Then, measure the depth from your countertop to your sink edge — this is the board thickness you will need. Buy the next thinnest standard material and use some nylon screws as shims to make up the thickness so your finished board will sit flush (the screws are needed because stick-on feet don’t stick very well to HDPE). If you are handy with a router, you can buy thicker material and rabbet-down the edge. We were lucky — a 3/4-inch standard layup fit our setup perfectly.

Note that if you have a flush-mounted sink, this project gets a bit more demanding. You’ll need an oversized template, and a rabbeted edge (which needs a router to cut), and the board can’t sit completely flush.

The HDPE cuts easily with hand or power saws. File and sand the edges smooth and you have a custom-fit counter extender and cutting surface, all in one. I also chose to cut a sink-access hole so that we wouldn’t have to lift the board out for pouring out a stale cup of coffee (or whatever).

Greg Illes is a retired systems engineer who loves thinking up RV upgrades and modifications. When he’s not working on his motorhome, he’s traveling in it. You can follow his blog at