The woods that I chose to use were basically just what I had lying around from other projects. The cutting board contains maple, walnut, mahogany, paduck, purple heart, cherry and sapele. I've found that one wood to stay away from using in a cutting board is a deep grained oak - the pits allow for food to build up and they are harder to clean. How much wood you need will depend upon the size of cutting board that you're making. I always think that it's a good idea to prepare more wood than you think you'll need because sometimes there are sections of scrap material with knots or blemishes that end up not being suitable for a project.
To be perfectly clear, when I say "scrap wood" I mean scrap hard-woods. And at no point should you attempt to make a cutting board out of a composite material like plywood or MDF, or out of any lumber that's been treated in any way, like pressure treated lumber.
- Joint an edge
If your scrap wood is already dimensioned, skip this step. If it's got rough edges or faces from the mill, you'll need to joint and plane them first.
Use a jointer to prepare one edge. This creates a straight edge which you can use later to push against the table saw fence to make a straight cut. It is generally the first step that is done with any raw lumber.
If you have a face that needs to be cleaned up, run the face of the board over the jointer as well. If your board face is wider than your jointer bed, you can cut it into a smaller piece (remember, you've now got at least one straight edge to cut against), or, use a variety of tricks by making a sled for your planer to hold the wood as it runs through directions for which can easily be found online.
Do this for all of your scrap pieces. At the end, they should all have at least one clean edge and at least one clean face.
- Plane the face
Next, take the already dimensioned face and place it face down onto your planer bed. Run the piece of wood through your planer. Do this with all of your boards that you are using, even if it already has two smooth faces. This will make all of your wood the same thickness. I try to keep my cutting boards as thick as possible so they have heft, and resist warping from exposure to moisture.
With that in mind, plane your scrap wood as little as possible. If you have one or two boards that are thinner than the rest, save them for another project, since planing all of your wood down to that minimum thickness wouldn't be worth it.
Try to keep the boards at least 5/8" thick, and ideally, 3/4" thick, or more.
- Cut into strips
This step is kind of fun - how often do you get to make "random and creative" cuts on a precision tool like a table saw?
Placing the previously jointed edge against the fence, cut strips of random width from your boards. Don't make any strips that are too thin (less than 1/2" for example) but vary them randomly over a range of widths.
There's no right or wrong here. If you like many stripes in your material, cut thin strips, if you want fewer strips to glue up, cut wider ones. I cut a whole bunch of different sizes with the small ones being around 3/4" and the wide ones at around 2 1/2".
- Lay out cutting boards
Once the strips are all cut, arrange them according to your tastes. I like putting walnut next to maple for nice contrast, and using the paduck and purple heart sparingly so that when it does show up, it really pops. Make the cutting board whatever size you like. mine is pretty big because I like to have a lot of room when I chop.
If you've only got a small amount of scrap material, think about making a cheese board or picnic board. Or, make 1 large blank and cut them down into 4 smaller boards and give them as gifts. Lots of options here.
Whatever dimensions you decide to make your board, glue them up as two separate halves that are no wider than the max width that your planer can accomodate since it saves a lot of sanding time if you an simply run the cutting board halves through the planer. My planer can't take much more than 12", so I arranged the strips into the large cutting board that I wanted, and then split that into two groups right down the middle to keep them both narrower than 12".
- Glue strips together
Separating your cutting board strips into two groups, no wider than the max capacity of your planer, glue the strips together using Elmer's® Carpenter's® Wood Glue MAX. I like using the Elmer's® Carpenter's® Wood Glue MAX version because it's waterproof, which is very important since these cutting boards will definitely be coming into contact with water when they got washed after use.
Lay a thin bead of glue down on each of the strips and use a chip brush to spread the glue evenly along the strip. Clamp the strips together and use some hearty pieces of wood as cauls to keep everything in line. Let the strips sit overnight and repeat this process for the second batch of strips.
- Sand and plane again
When you remove the clamps you should now have two panels, each 1/2 the width of your cutting board. Use a palm sander with a rough sanding pad to quickly remove the biggest glue marks on the wood.
Then, run the two boards through the planer, taking off as little material as possible on each of the faces to take off the remaining glue marks. The boards should now be perfectly flat on both sides.
When they come out of the planer, you can really for the first time get a preview of how nice your cutting board will look. It really pops!
- Glue two parts together to form one large board
Glue the two boards together using the same technique of squeezing out a bead, spreading the glue evenly with a chip brush and finally clamping over night using cauls to keep everything aligned as mentioned in the previous step to form the full size cutting board.
Remember, the resulting glued board won't be going into the planer and will have to be sanded by hand, so take extra care when clamping to clean up squeeze out with a wet rag, and or scraper. It's easier to clean up wet glue than to sand off the dried stuff.
Switch to a longer clamp if you have to for this glue-up since the board is starting to get pretty large. See me using pipe clamps in the second photo below.
- Sand again and trim to size
Use the palm sander to take off any glue marks and trim the ends of the board to the same length.
The cutting board I made was too wide to fit in a table saw sled or my sliding miter saw to trim the edge, so I used a circular saw and straight edge instead to cut off the uneven edge.
*Note that this will set the length of your board, so pick something that's nicely proportioned to the width and make the cut. This can be a good time to think about whether or not you'd like the board to fit into the sink. I have a few cutting boards that fit entirely in my sink. I use these for cutting meat so they can be completely submerged and thoroughly washed.
The board that I am making in the picture below however is significantly larger than the average cutting board, but I still wanted it to be able to drain into my sink. The answer here is to make at least one dimension, the length or width, and in this case the width, less than the largest dimension of your sink so at least you can wash the board at an angle in the sink and not make a mess.
- Round over edges
I rounded over the top and bottom edges of the cutting board with a round over bit on the router table. Using a round over bit with a bearing, and the router table fence as a backup makes this job very easy.
Use a sacrificial follow board as pictured in the fourth photo to prevent any tear out.
- Rout juice groove
I like to add a groove to one side of my cutting boards to collect the juice that accumulates so that it doesn't make a mess on the counter top.
Put the router into the plunge base attatchment and fit it with a rounded groove bit. While there are many ways to cut a juice grove, including using the router table again with stop blocks, or the router with an edge guide, the easiest way for me is to fit the router with a simple pattern bushing and follow a rectangular piece of masonite that I cut to size as a template.
Size the template to the specific size of your cutting board, taking into account the offset of your bushing and groove bit that you use.
I used painters tape to hold the pattern board in place while I cut the grove into one half of the board. I then spun the board, switched the tape carefully to the other side, and finished cutting the grove.
The plunge base is essential here because it allows you to plunge down into the wood to start the cut, and not have to come into the wood from the edge.
Depending on the size of your grove, cut it in one, or two passes, removing a conservative amount of material each time - better to make two easy passes than one deep, slow pass which might result in burn marks in the grove from when the router was strained.
Additionally, I don't like to make my groves too deep because they become hard to clean, and it's unrealistic that my cutting board juice groove will ever have to accomodate say, 1 cup of liquid.
Be careful coming around the corners of your template, as this is the hardest part. To make the corners easier, simply round the corner of the pattern template on the belt sander just a bit. This will make rounding the corner with the pattern bushing much easier than going around a sharp 90 degree turn. Thanks for the tip Dad!
- Finish Sanding
With all of the woodwork done on the cutting board it's time for the final sanding. Sand the board using a random orbital palm sander with finer and finer discs until you reach 220 grit. I like to put items to be sanded on a expanded mesh foam pad so that they stay firmly in place.
- Apply food safe finish
The final step is o apply a food safe finish such as mineral oil or butchers block oil.
I like using a food safe gel varnish because it's easy to wipe on and off and results in a nice satin shine.
Make sure whatever finish you decide to use penetrates your wood well, and that you apply more than one coat if possible. The wood will be exposed to a lot of moisture if you use it frequently, and keeping the finish in good condition is your best protection against warping from water damage.
If you've got any extra material leftover from this project, use it to make a Magnetic Knife Stip.