Introduction: Sliced Wood Coasters
I love finding new ways to reuse things, like old tree branches that lay discarded on the side of the road. I also must really like coasters, as this is the second time I've made wood coasters. Last time, I really liked that you could clearly tell the coasters were from a tree, and with this project I wanted to remix the idea by slicing the wood into discs.
These coasters did have a process to create, but were fairly easy. The best part is that I made loads so I can give them away as presents :) Here's a video of how I made them, and a full write up below.
I decided to leave the coasters with a stain only, without sealing them, allowing any rings from drink condensation or stains from spilled drinks to add to their character.
Ready? Let's make!
Step 1: Source Branches
Finding dead tree branches is really easy, if you're looking for them. Next time you're on a hike or cleaning up your yard you'll see branches of all sizes which can be used for this project.
I happened upon a very large tree branch near where I live. It had been dead for a while and there was very little moisture in the branches. This is important because if the tree branches are 'green' then the wood still has plenty of moisture and will warp while it dries over time. Look for dead branches, but don't go ripping limbs off trees.
Step 2: Cut Slices
To make these sliced coasters I used branches that were about 0.5" - 1.5" (12mm-40mm) in diameter.
I used a benchtop bandsaw to cut these slices in the branches. I found my bandsaw from online classifieds for about $50 and it works great for quick little cuts like this. Buying a new bandsaw isn't that expensive, and once you have one there will be all kinds of new projects you can tackle.
Using branches from about 1.5"-0.5" in diameter, slices were cut on the bandsaw that were about ¼" thick. TO help steady the wood (and protect my fingers) I used a scrap piece of PVC to help guide the wood through the blade.
I separated the wood slices into small, medium, and large piles. These piles helped me space out the array of slices on the plywood and ensured there was an even distribution of sizes across the entire board.
Step 3: Plan Out Sizes
Before gluing any of the wood slices to the plywood sheet I sketched out a few sizes to get an idea of how large I wanted my coasters to be.
Using a carpenter's square I made a few square shapes to see what sixes look best. I ended up stealing one of my wife's nice felt coasters to use as a template, which was 3.5" x 3.5". I'd use this as a my cut measurement after gluing the slices to the board.
Step 4: Start Gluing
I glue the slices to the plywood using Titebond III wood glue. I used this specific adhesive as it's waterproof when dry, and since these are coasters for drinks I thought that would make the most sense. However, any wood glue would work fine. A dab of glue is applied to one side of each slice, which is then stuck to the plywood board.
In my Woodworking Class I teach that gluing end grain is not advised, as the porous end cuts of wood offers no long grain for the adhesive to bind to. In this case, since there is no load forcing the slices away from the plywood back, gluing end grain will work. Making a bit of a mess here is fine, as the spill-over glue will seep between the slices and bond the sides together, and any residual glue on the tops of the slices will be planed off once the glue has dried.
I made sure to have some of the slices overhand the edge of the plywood, which would give a cut edge when tidied up in the next step. I also did not cover the entire board, leaving one squared edge as a reference for cutting the strips of plywood.
The glued slices were allowed to dry completely overnight before any cutting.
Step 5: Make Slices
The end of the plywood board that was not covered with slices was the reference edge. This square edge was placed against the table saw fence to make nice straight cuts.
The fence was moved to cut just the edge of the plywood board, slicing off the overhang slices first. Using my measured coaster size of 3.5" the fence was reset to make a slice 3.5" wide. The fence was reset for each successive cut, creating strips of plywood that were all 3.5" wide until there was no more board to cut with glued slices on it.
Step 6: Router Planer
To get the irregular height of all the glued slices consistent I used a router planer. This is a regular hand router attached to a wide base that will ride on rails over the piece to be planed. A wide flat end bit will be passed over the strips of glued slices and lowered after every pass, slowly trimming the taller slices until an even surface is achieved. It's like a wood haircut :)
I made an Instructable all about making your own router planer, if you want more detail on how to make one.
A thick piece of scrap plywood is used as the base, and openings were drilled to match the base plate screw holes, and the large opening for the router bit to pass through.
The strip of glued wood slices was hot glued to the workbench to secure it in place. Two identical scrap wood rails were hot glued to either side of the piece to be planed, these will be the rails wide router base will ride on. The rails need to be identical to ensure a level cut, and will need to be taller than the highest piece you are attempting to plane, otherwise the router base won't be able to pass over the piece.
Start with the router bit retracted into the router as far as it can go and make a shallow pass over the sliced wood piece to remove the tallest slices. Turn off the router and lower the bit about ⅛" and then make another pass. I like to make many shallow passes instead of fewer deep passes, as there's less chance of tear-out and there's much more control over the tool. Continue making passes until a level surface is achieved.
Pry up the strip of leveled sliced wood and glue down the next piece to be planed. Repeat until all pieces are planed down.
Step 7: Sanding
Planing with the router will likely leave a surface that will have milling marks. This is an unavoidable surface quality after such an abrasive tool operation, but luckily it's easily removed by sanding.
Starting with a coarse 80 grit sandpaper on a random orbital sander the surface of each strip was sanded down to remove the milling marks. The sandpaper was stepped up through to 200 grit to create a nice smooth surface. You can learn more about sanding in the Sanding Lesson I wrote for the Woodworking Class.
Step 8: Cross Cut Strips
Once the strips of glued wood slices have a nice smooth finish they can be cut into squares. I used a simple table saw sled that I made in an afternoon to make these cuts. This saw sled is great as it makes reliable cuts and only uses one miter slot, so it never binds on the table.
I measured out 3.5" from the kerf of the table saw sled and set a stop block there. The strips of glued wood slices were passed through the saw blade to make square sections, revealing the coaster shape.
Step 9: Stain
To finish the coasters I used a teak oil stain, which will seal and color the wood. I considered having an epoxy resin coating, but prefer the natural wood look over something shiny.
A liberal application of teak oil was applied to each coaster with a lint-free rag. More teak oil was used than usual since I needed to get all into the areas between the slices to get good coverage.
Step 10: Bumper Pads
To keep the coasters off the table surface, and prevent them from sliding around, I used clear hemispherical bumper pads. These are self-adhesive and will be hidden under the overhang of the coaster, so won't obstruct from the clean look of the edge.
Step 11: Coasters!
These coasters are a great addition to any party or dinner event, and look good with or without a beverage on top. Each one is a little different, and by not using an epoxy finish the feel of natural wood is still there.
I made about 15 of these coasters and they were all snatched up by friends and family immediately after I took these photos. Looks like it's back to the shop to make some more!
Happy making! :)
Have you made your own sliced wood coasters? I want to see them!
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