These crafty coasters use seemingly boring data cables which have been sliced into small segments, revealing their colorful insides.
Using casting resin to keep everything together there's no limit to the combinations the cables can be placed, meaning you can create all kinds of designs (not just the random assortment I did). The best part is that data cables are super easy to find from old electronics like printers or communication cables, or any e-waste recycling center.
This easy project took an afternoon to make, and then overnight to let the resin cure. Once you've got all the parts set up there's no extra work to make a set of 4, or even 10 if you like.
Ready to get casting? Let's make!
Step 1: Gather Cables
To make the most interesting and colorful coasters you need cables with lots of strands inside. Just because a cable is thick doesn't mean it has lots of interesting wires inside. The way you can tell which cables are going to be good is to look at the plug ends of the cables, the more pins/slots the more wires inside.
Printer cables are great for this, there's usually 10 or more pin connectors on these types of cables, which usually means lots of colorful wire inside.
To make clean cuts I used curved jaw cable cutters. These cutters slice the cables cleanly and don't crush the cables like regular diagonal cutter do.
Here's a great cross section of a printer cable, cleanly cut without crushing the cable.
Step 2: Round Form
To make a round form to pour the resin into I used a 4" diameter PVC pipe. Any smooth and round object could work for this, like disposable cups, soda cans, or plastic bottles.
The PVC pipe was cut into rings about ¾" - 1" thick. That gives enough room to cover the cut cables and have a little wiggle room.
I tried a few different types of pipe to make the forms. PVC or ABS is a great choice as they are smooth, readily available, and inexpensive.
Any burrs or rough edges were sanded smooth with 120 grit sandpaper.
Step 3: Cut Cables
The cables were gathered up and cut to length with the curved jaw cable cutters.
To make things easier (and much master) I clamped one arm of the cutters to the table, allowing single hand action and leaving the other hand free to feed the cable through the cutter blades.
I wasn't too concerned about perfect length consistency, but all were generally around ¼" in length. The inconsistent lengths would be resolved when cased in resin.
Step 4: Some Cables Were Difficult
Some cables had nylon strands packed along the length, leaving the cut cable pieces somewhat connected. It looked a little like a caterpillar.
I tried removing them individually, then tried clipping them with scissors. Eventually, I used a propane torch to singe the nylon strands off and separate the cut pieces.
Step 5: Packing the Forms
Once all the cables were cut to length they could be packed into the circular forms. The forms were first glued to a smooth surface. Formica or acrylic sheets are great for this as they are flat and the resin doesn't want to stay stuck once it's cured.
The circular forms were hot glued to the flat surface (clear acrylic in my case), ensuring no gaps around the form that would let resin escape.
Once the forms were glued to the smooth surface they were packed with the cut cables, ensuring to vary the types used so there were minimal similar cables next to each other.
The cable pieces were packed as tightly as possible into the forms. I used a pencil as a wedge to help jam a few extra pieces in the already tight space.
Step 6: Resin
I like using 1:1 ratio resin, which is 1 part resin to 1 part hardener. These types of resin are simple to work with and don't have any calculations to keep track of, just measure out equal parts of each and mix. I'm using this resin, but this technique will work with any type of resin you like.
I eyeballed how much resin I wanted to use and made a mark on 2 paper cups using a stack of things to draw an even line on the outside of the cups.
To get the best casts the resin and hardener should be warmed in a bath of hot water. Fill a large bucket with hot water from the tap and put both bottles into the bucket and leave for a few minutes. Remove from the bucket and towel off, then open up and pour equal parts resin and hardener into separate cups.
Step 7: Prepare to Pour
When the resin and the hardener are combined a chemical reaction starts, which means the timer is ticking to finish pouring before the resin begins to set. Knowing this, prepare the forms and anything else you need before combining he resin.
Pour the resin and the hardener into a new cup and begin stirring. Ensure to mix the contents thoroughly, scraping the sides and bottom of the mixing cup. Make sure not to whip the mixture as you're stirring, which can introduce air bubbles. Though more resins have agents that degas them, it's a good idea to avoid introducing more bubbles than necessary.
After mixing for about a minute you can start pouring the resin into the forms.
Step 8: Cover Cables Completely
Pour the resin into the forms until the cables are completely covered.
I find the best results were from where the resin was poured into a single location and allowed to flow through all the gaps and fill the form.
If there are any air bubbles in the resin give it a minute or two for the bubbles to surface, then they can be popped by breathing on them or with a propane torch passed over them.
Step 9: Demold
After 24 hours the resin has cured and is solid. The resin pucks can be pushed from the forms after they have been removed from the smooth surface.
Once the resin is removed from the mold you can see the high-gloss mirror like finish.
You could easily stop here, but I wanted to clean up those edges a little.
Step 10: Router Edge
I wanted to remove the sharp edge and make a smooth roundover. For this I used a router with a ½" roundover bit.
Routing leaves a rough finish that needs to be snaded smooth. I started with 400 grit sandpaper and stepped up in increments to 1000 grit wet sanding. This will sand out the rough finish and make it nice and shiny like the rest of the coaster.
Sand until you've got the finish you are looking for. If it's still too hazy step up to a finer grit.
Step 11: Start Serving
With the edge all polished up this coaster is ready to hit the table. The visual texture of the colorful cut cables is a feast for my eyes. Make a few for home, or gift them to your techie friends, these coasters are sure to be a conversation starter.
Have you made your own resin coasters? I want to see it!
Share a picture in the comments below of your creation and you'll get a free Pro Membership to Instructables.
Happy making :)