WOW your friends with some cool hand made coasters*! You don't need a fancy laser cutter or a CNC machine to make some really cool stuff. You can make anything a CNC machine or laser cutter can make, just by using a few inexpensive tools like a scroll saw and router. Ok, it might take a little longer but hey... you get the satisfaction of knowing you made something with your own hands!
I am using a Dremel 4000 with the Dremel Plunge Router attachment. If you have a more powerful router, you can probably route this project in one pass. I had to do it in three passes.
Also, I filled my design with wood shavings. You don't need to fill them with anything, or use something else if you wish. Use your imagination!
*This instructable uses an image of the ZUMBA symbol, but you can use any image you like.
Step 1: Supplies
1. Safety Glasses\Goggles
2. Dremel Plunge Router \ or other router
3. Dremel 650 1/8" router bit (or equivalent)
4. Dremel MotoSaw \ or other Scroll Saw
5. 10" x 10" x 1/4" thick plywood (or wood of choice)
6. Ruler \ Square
8. Pattern (provided - attached PDF)
10. Exacto \ utility knife
11. Drafting Compass
12. Sand Paper (220 grit)
13. Sawdust \ Shavings
15. Paint or Food Coloring
16. Clear bar top epoxy resin
17. Adhesive back felt
18. Mixing cups and spoon (or something to mix with)
19. Latex gloves
Step 2: Find Centers of the Coasters
1) Divide 10x10 piece of 1/4" thick wood into four sections (see image find-center_step1).
2) Find the center of each section (see images find-center_step2 through find-center_step4).
3) Use compass to draw circles (see image find-center_step5).
Step 3: Cutout Pattern and Trace Inside Each Circle
1) See images (tracing_step1 through tracing_step4).
Step 4: Route First Pass of Design in Each Circle \ Sand With 220 Grit Sand Paper
1) Setup the router initially so the bit is touching the surface when the depth gauge reads 1 inch (see image bit-set-begin_1inch).
2) Once the bit is tight, set the router for the first pass - One third of the way between the 1" and 1-1/8" mark (See image routing_pass1_depthGauge and routing_pass1_depthCheck).
3) Route the the first pass for all four patterns. You will need to stop frequently to vacuum or blow out saw dust and lightly sand the burred strands as you move along (see images routing_pass1_01 through routing_pass1_04).
4) Sand lightly, the entire piece, to smooth out all burrs (see image routing_pass1_05).
Step 5: Route Second Pass \ Sand Again
1) Set the router for the second pass - Half way between the 1" and 1-1/8" mark (See image routing_step2_depthGauge).
2) Follow the same procedure as you did for pass one. This will be easier since you already have a guide path to follow from the first pass. The burrs won't be as bad for this pass and you can use this pass to clean up the pattern a bit (see images routing_pass2_01 and routing_pass2_02).
Step 6: Route Third Pass \ Sand Smooth
1) Set the router for the third and final pass (see images routing_pass3_depthGauge and routing_pass3_depthCheck).
2) Use this pass to reach the final depth (1/8"), clean up the image, and smooth out all the lines. (see images routing_pass3_01 through routing_pass3_03).
Step 7: Cut Out Coasters
1) See images (motoSaw_cut1 through motoSaw_cut4).
Step 8: Sand Edges With Dremel Drum Sander and Completely Sand Smooth
1) Use the Dremel drum sander (120 grit) to sand all the edges (see image sanding_01).
2) Sand all the coasters smooth with a 220 grid sand paper (be sure to sand all the pencil marks away).
Step 9: Airbrush Edges for Sunburst Look
1) Using an airbrush and airbrush paint (or food coloring as I did for these), lightly paint the edges to give it a sunburst effect (see images paint_step1 and paint_step2).
Step 10: Fill the Design
1) Using a liberal amount of glue, fill the bottom of the design and spread it around with a swab of some sort to fully cover the bottom. Do not use too much glue, just enough to make the shavings hold in place (see images fill_design_step1 through fill_design_step5).
2) Sprinkle the sawdust\shavings inside the design and pack it in good and tight (see images fill_design_step6 through fill_design_step8).
3) Shake and wipe off excess sawdust\shavings (see images fill_design_step9 through fill_design_step11).
4) Let dry overnight.
Step 11: Mix and Pour Glaze Coat
1) *OPTIONAL: At this point I decided to give my coasters a bit of flare by dusting them with a fine gold glitter. I purchased this through smooth-on, but you can use any glitter that you desire. I chose this because it is extremely fine and will give a very subtle shimmer. (see images glaze_coat_step1 and glaze_coat_step2).
2) For the epoxy coating, I purchased this FAMOWOOD GLAZE COAT from Lowes (see image glaze_coat_step3). READ CAREFULLY AND FULLY UNDERSTAND THE DIRECTIONS OF THE GLAZE COAT! YOU MAY WANT TO TEST RUN ON A SMALL PRACTICE PIECE BEFORE MIXING UP ENOUGH FOR THE COASTERS.
3) Mix Glaze Coat according to directions and pour "very slowly" over coasters to create a nice thick coat (1/8" or so). Make sure to even everything out and go around the outside edges. (see images glaze_coat_step4 through glaze_coat_step7). Just like any other liquid, this will self-level so it is important to keep the coasters as level as possible.
4) Leave them in a "CLEAN" dust free, warm, dry area until completely cured. Use a hair drier or heat gun to help remove any bubbles that occur after pouring. (see images glaze_coat_step8 and glaze_coat_step9). Bubbles will most likely continue to to rise so keep checking them every five minutes for the first 1/2 hour or so, and use the heater\hair dryer as necessary.
5) This will take at least 24 hours or more to setup, and up to a week before you are ready to use the coasters. DO NOT BE IMPATIENT!
Step 12: Add Felt to Bottom
1) Before the Glaze Coat sets, it is a good idea to pick the coasters up (holding from the bottom - careful not to touch the surface) and remove the excess that drips around the edges. I did not see all the drips on a few of the coasters and had to wait for them to completely cure (see image felt_backing_step1). After they cured and completely dried I sanded down the bumps with my Dremel using the drum sander.
2) Place the adhesive back felt face down and set the coaster on top of it. Mark around the coaster to make the circle. (see image felt_backing_step2).
3) Cut the circle just inside the traced line so the felt is slightly smaller than the coaster. (see image felt_backing_step3).
4) Peel the back off the felt and stick to the bottom of the coaster (see image felt_backing_step4 and felt_backing_step5).
5) Wha-Lah! That’s it! Now enjoy a nice place to set your cold (or hot) drink (see image done)!
Step 13: Alternatives...
Here are a couple others I did using a walnut stain and red cherry stain.
Now go and enjoy your router and scroll saw!