I'm going to show you (as best as I can) how to make light transmitting concrete. Google it, and you will be amazed at how beautiful it is! I was desperate to get my hands on some...but considering the cost, I decided to make some with stuff I already had around.
This material has the strange effect of looking shiny or sparkly...but it's dull concrete at the same time! It's very entertaining to show off or play around with.
If this material interests you, check this article out:
http://www.impactlab.com/2009/03/07/litracon-see-through-light-transmitting/
Here is the HD video:
Here is the normal video:
Remove these ads by
Signing Up












































Visit Our Store »
Go Pro Today »




I ended up having to make this thing twice. The first time, I really messed up the water to concrete ratio on the mix, and when I tried to demold it, it was very crumbly and pretty much fell apart.
http://flic.kr/p/bKoXPT
I took photos of the construction of the first one, but didn't photograph the second one until it was complete. I learned quite a few little techniques on the first try that made the second attempt go much easier, so I'll describe those techniques as I go.
I started with the clay base. Then I printed his logo in black on my HP inkjet printer, cut it out, pressed it onto the clay, then wet the back of the paper and dabbed it a bit with my finger. HP inks are water-soluble, so when you peel the paper away, it's transferred enough ink to see what you're doing onto the clay.
http://flic.kr/p/bKoX7T
The second time round, I decided that was still too hard to see, so I filled the design in with Sharpie. This helped a bunch.
I started putting fibers in one by one with plastic tweezers, but the fibers are so low-contrast that I had a very hard time seeing where they were going and where they needed to be.
http://flic.kr/p/bKoWn8
So I used a highlighter to color about the last quarter inch of the fibers, and worked under a blacklight, and I could see what I was doing just fine. The inked part of the fibers ends up in the clay, and it doesn't bother the finished piece.
I also discovered that an incense holder makes the perfect staging area for fibers, the ash trough makes it very easy to pick them up individually with the tweezers.
http://flic.kr/p/bKoWPg
After it was cast (and I fixed a crack with epoxy), I polished it up as best I could on a disc sander (killing 2 discs in the process), and covered it with several coats of triple-thick glaze.
http://flic.kr/p/bKoRoD
On one side is random dots of light...
http://flic.kr/p/bKoRPp
On the other, a logo!
http://flic.kr/p/bKoS36
Oftentimes, crumbling happens because of too much water. In order to get regular concrete thin enough to fill the spaces around the fibers, it's too wet and cures strangely. Rocktite is really magical stuff, you can't add too much water. It pretty much cures no matter what.
A secret I learned from casting lots of stepping stones is that once you open a bag of concrete, you have to either use it within 24hrs, or put it in an airtight garbage bag and seal it really good. Old, opened concrete will pretty much crumble no matter what you do with it (absorbing water in the air reacts the lime in the micture)
Rocktite seams to work fine even if its left exposed for a very long time.
The fibers I used were from an LED fiber optic lamp I found at the dollar store. I snipped them to length with scissors.
I presented this piece to the owner of the concrete business, he really enjoyed it.
He gave me some tips on working with concrete. Firstly, concrete will always shrink a bit. If you don't want your piece to shrink, use non-shrinking grout mix instead. (he gave me an 80lb sack, yay!) He said it probably crumbled because I put too much water in. The grout apparently doesn't have that problem, you can mix it thinner if you need.
www.clydelynds.com
First saw an example of his work back in '88. Looks like he's gotten more sophisticated.
My Cousin is in Peru helping villagers to add sky lights to their huts. They use a clear plastic pop bottle filled with water (clorinated to keep out green stuff)
It is embedded in the ceiling and sticks out of the roof. It channels sunlight into the hut and apparently lights up as well as a 60 watt light bulb. As long as the sun is shining!
you can read about the process on Karl's blog at:
http://krrrl.blogspot.com/2011/08/august-8-2011.html
1) Sticking the fibres into the concrete AFTER pouring the concrete into a mould,
and
2) having less space in between the fibres to allow more light to pass through
Thank you in advance :D
Here are a couple other things i was thinking abewt:
1) if you want uniform light transmission, maybe one could use a mesh or some such thing to distribute the fibers evenly over the surface.
2) Well, what about non-uniform light transmission????!!! Sounds like something with real potential to me. What if you varied the density? You could create areas of gradient,highlight or shadow or an entirely new design or swirly pattern within your piece, which could really add an interesting dimension to a sculptural piece that was a low- or medium-relief.
You know, if you want to color the material, you don't necessarily have to use paint. You could conceivably use a colorant, like iron oxide (or one of those marking powders they use for carpenter's chalk lines, some of which are iron oxide) or a mason stain (sold at ceramics places) and mix it into your goop. If you are using cement, you can make it brighter and less gray by using white Portland cement instead of the ordinary dingy gray variety.
I'm searching for a way to clean up the crushed glass from the recycling center to use. It's got too many label bits stuck to the glass.
I made some fine crushed glass with a capped steel pole and a baseball bat. Just pound away until its like a dust.
The true litracon (or a near version) uses a mix of fluorite, cement and fiber glass.
Nice work!
Also, we used to use monofiliment fish-line for fiberoptic lamps and art; its way way way cheaper by the foot than plastic fiberoptic cable. The results look the same to the eye, it just isn't suitable for data transmission.
BTW, in my first post I meant to say, "... will not ONLY make a structure lighter..."
It will make it lighter, of course.
Your ible has set my mind in motion; cool. I'm thinking of replacing half of a dying sliding patio door with a panel of this translucent concrete. Thanks.
Partheon
In Africa, carbon ( like black charcoal) is added to river clay to make it able to withstand repeated firings. This 'fire clay' is used to make kilns and glass slumping molds.
I had a couple ideas (I'll post them separately). First, to more quickly place the fibers in the clay, I was thinking that, after you cut them to length, you could line them all up (perhaps in a shallow tray of some sort) and then use a thin but long strip of tape (double sided?) to pickup the fibers. I'm picturing the tape running perpendicular to the direction of the fibers. This should create something like a "rope" of fibers that could be snaked along the clay (sticking the fibers on one side of the tape into the clay). The tape itself should end up completely surrounded by the cement. The end result might look a little different since the fibers would be sort of lined up instead of totally spread out but I think it might look ok. Ideally there would be some space between the fibers stuck to the tape and not totally side-by-side. This is just an untested idea...
Or maybe you could build a rig out of plastic; make a top and bottom piece with evenly spaced holes in them and thread the fiber optic through both, and then mount the rig inside a mold and pour the concrete. Maybe stretch clingfilm over the bottom piece before threading through the fiber. Don't know if it would work, but it could make larger scale production easier.
with a single longer tine and a small bifurcation to push the hair into place. we were punching hair into silicone or foam latex, though.
maybe if you used painter's canvas and either laid a dot pattern out or just punched the little fellas through how ever maybe a little UMR or spray release so the canvas doesn't bond to the cement.
awesome Ible, nepheron!
A layer of wax
A piece of screen raised quarter of an inch above that
Fill every hole with 1 strand
pour wax until it covers the screen
and finally cement
great idea, drakesword!
y'know it occurred to me.... those little polywhisker light guys, if you attached them to LEDs (or didn't trim them off the light source) and made a quicky mold of an inflatable ball, then cast them in as a quarter or half dome ( 1 1/2" walled hollow)
you'd have a very pleasing nightlght or sconce, i could even see using the pumpkin-stencil idea in conjunction with your fiber segregation screen idea to create awesome picture lights...
seems like it would make it easy to do ben day dots & halftone patterns too!
I'm going to try it.
First picture is a typical flagstone. Some are perfect squares. I don't like that!
Imperfection is cooler
Second picture is the box.
There is a single piece in it which can be placed and moved depending on what shape I want.
I want each stepping stone to look unique so i will have to make the dividers movable
The third is of a light on the optic fibers held together with my hand (the uv light shows up so bright on camera!)
First off i did some modifications
For a rock like effect I made a clay layer on top of the wax layer to give it some rough pits and groves.
I made the fiber optics long enough to be bound and moved off to the side.
here is where my idea starts
Just messing around I put a blue and a uv led behind my rock.
to get some cool effects so I could make a "zen garden" with mood lighting!
--> a piece of 3/4 in plywood with fiber optic pilot homes
--> spreayed with some sort of urithane
----->procede to place optic strands in holes
----->Thin layer of wax (hold strands, prevent sticking, easy to break)
----->Then your cement (i used mason cement for my stone)
Then bind all of the strands in one area
Followed by solar garden light
Perhaps, while it's still in the mold but cured a number of hours, you can spray something such as spray-on silicone or even PAM, onto the surface that still has fibers sticking up out of it, and lay down a second layer of cement, let that cure, and then separate both.
Perhaps twisting the 2 pieces at the separation point, or running a long blade (such as a hacksaw blade) between the two would separate it without breaking the strands - not sure, maybe the lubricant would cause the fibers to slip right out of the concrete, but it might be worth testing out. If the fibers get a bit damaged from whichever method you separated them with, you're going to sand it down anyhow, so you'll probably end up sanding past the frayed parts.
Thanks for the fantastic Instructable!
Or build the mold so it forms on its side with the clay going up the middle and both ends?
like this
{|__[]__|}
Mold Clay Cement Clay Cement Clay Mold
Disneyworld has fiberoptics wired through the concrete sidewalks in the center of Epcot. I imagine you could use pizzaboxes as molds for patio blocks, and use a connected fiber optic system to create the fibers, instead of cutting them off a toy? Wouldn't that make a cool patio?
There are lots of great ideas in the comments as well.
Has anyone tried arranging the fiber optics into a design? or picture? (think of the old dot matrix black/white photos)
This company is doing some of this type of stuff, though not quite as cool, in concrete and acrylic.
http://www.sensitile.com/
What brilliant ideas !!!
in regards to lighting for the bricks, a battery case available at most electric hobby/toy shops with a switch and light globe/s of your choice can be placed inside the brick when making the brick.
this has opened a can of worms i am sure. can't wait to experiment as I am writing this. thanks all !!
Anyway, could you:
1)use a long PVC pipe, slit in half and re bound into a tube, with mold release applied, as a form,
2) string long strands of fiber optics running along the length
3)fill with concrete (how to keep the fibers interspersed in the middle, I don't know) and let set
4) cut the concrete cylinder with a rock saw into disks and polish
I dunno, any thoughts?
yo said somewhere in the comments that you had experimented with strips of water bottles in place of the fibre optics. any picture of these? would be interesting to see
Do as instructed above, but use longer fibers and a deeper dam wall.
Then after it cures pour a thin layer of plaster of paris or some other water soluble solid. Let that cure, then pour another layer of cement. Alternate water soluble with cement until you fill the container. Wash out the plaster, break the glass, polish as already instructed.
If only there were a faster way to mount the fibers...
And the faster way to mount the fibers is... in wax.
Bundle the fibers at one end. Cool melted wax until it is nearly ready to solidify. Dangle the fibers into the wax, and spritz with spray bottle of water to congeal the surface quickly. It might take more than one bundle to cover the entire tile area.
Then proceed with your tile-layering idea!
For larger surfaces, you could make a board as large as the surface you want to make, and fix several bundles in it, with sticking tape or something.
Lower the board to dip the fibres in the wax, and pour the concrete in evenly spaced holes you made in the board in advance.
After the concrete has hardened, you could use a hot wire (like you use for styrofoam cutting) to cut all the fibres at once (if they're made of plastic).
You can also leave the bundles intact to connect a light source to it like Drakesword suggested below.
Remove wax, use an orbital sander or something, and you're finished.
Too bad that method wouldn't quite work on heavy walls... or maybe it would?
Either you need a machine to put the wall upright, or you could do it block by block, making sure the fibres are nicely distributed along the edges to make it look continuous. The possibilities!
Looks like I'm gonna have to give this a go...
I saw this in an architectural magazine a few years back. As far as I know, that designer was the originator of the idea. He had an entire wall made of this stuff. It was absolutely stunning.
If I can dig up a pic of it, I'll post it. You could see the entire silhouette of a person walking by on the opposite side.
Yeah, I was thinking about 12" diameter, 2-3" height, ovals or circles, to use as stepping stones or exterior wall decoration, and power it by solar,
www.instructables.com/id/How-to-Make-a-Solar-Powered-Walkway/
Seems like it could easily be expanded to some killer LED backlit pathway stone pavers.
Hmm...that sounds like an interesting idea...
With a bit of patience, one could make a few very large pieces..
www.dsaprojects.110mb.com/electronics/clocks/analog_clock.html
www.instructables.com/id/How-to-Make-a-Solar-Powered-Walkway/
suggestions for garden ambience anyone?
I've done some research into using plastic bottles as the fiber optics...beleive it or not, it actually works...
Cutting a plastic bottle into strips no longer than 2 inches work pretty good as fiberoptics.
pour the concrete as usual.
bind the loose ends of the optics together and hotglue onto a solar pathway light's led and tada all done. Solar concrete pathway
Love the electric mini kolimba and hickory bow on your blog too.
It took me maybie an hour to put it together. Maybie overnight to let the concrete cure.
you could strip the leds from the fiber optic toy you used