I've used this 'loaf' method to crank out numerous coaster sets for easy cheap gifts or craft fair inventory. Making them out of plywood is the cheapest source of material and still gives you an interesting enough end product. The basic concept is laminating a stack of plywood discs together into one long log and then slicing it up.
- (1) piece of 3/4" plywood (preferably something furniture grade with no voids) 24"x48"
- (1) 36" length of 3/8" diameter dowel (the one shown is oak)
- Wood glue
- (2) 36" long pipe clamps
- Sander, belt or orbital
- Chopsaw (must have angle adjustable base)
- Small laminate trimmer router (optional)
Step 1: Plywood Discs and Sled
The first step in the process is to knock out about 36 plywood discs. The discs I made are 3-1/2" in diameter but you can make them any size you'd like. Each disc has a 25/64" hole in the center. The hole is slightly oversized to allow a 3/8" dowel to slip through the center to help align all the pieces.
I used to make the discs with the circle cutting jig for my plunge router shown in the attached pic Fortunately I live in the Bay Area and I now make these at TechShop with the help of the CNC ShopBot. I can now knock out the 3 dozen discs in about 30 minutes of machine time. I also recently assembled a sled for holding the log which is a great help in the upcoming slicing step.
Once all the discs are cut start slipping them on to a 36" length of 3/8" dowel. Don't be shy with the wood glue in between layers. Squeeze them all together with 2 pipe clamps. The extra length of dowel gives you something to hold onto when your cutting towards the end of the log.
When the glue is dry it's time to sand. A benchtop belt sander makes pretty quick work of this but it can by done with a handheld small random orbital sander. Doing it by hand always reminds me how much sanding has become my least favorite part of any project.
Step 2: Slice Your Loaf
Now it's time to slice up some coasters which means it's chopsaw time.
Set your chopsaw at about a 5 degree offset. The offset is the key to cutting through the various layers in the plywood and exposing different grain patterns.
Draw a straight line along the length of your log. Keep this line horizontal as you slice the coasters so that the slight angle to the cuts will always be parallel. I cut each coaster at slightly over 1/4" in thickness. I found that if I go any thinner the coasters would sometimes spin up the blade and wedge themselves inside my chopsaw. You can cut these without the sled I've made but if you have the time to make one it really helps stabilize the material and reduces blowout on the back side of the cut. I put a mark on the sled so that I can keep the thickness consistent. If you cut them without the sled you'll need to clamp a stop in place.
One small step that I do is to rout the end of log between each cut with a 1/8" radius roundover bit on my small laminate trimmer. I think this helps identify a 'top' side to the coaster and adds a nice touch.
I've found that the loaf produces about 10 sets of 4 coasters but it all depends at the thickness you cut them at. A couple rounds of sanding from 80-220 grit and some spray lacquer and your done. Feel free to explore different staining and finishes.
Step 3: Other Options
I like the plywood because the numerous layers guarantee a different grain pattern in each cut. You can use pretty much any material to produce your source loaf. I made a batch out of scrap hardwood pieces from the cutting boards I make. Obviously this gets a little pricier but that's why I serve High Life on the plywood and bourbon on the hardwood.
Hope you enjoyed this project, thanks for looking!