Make Your Own Mini "Concrete" Door Lamp!

by JGJMatt in Workshop > 3D Printing

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Make Your Own Mini "Concrete" Door Lamp!

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Hello fellow makers,



Almost 3 years ago I posted this Instructable on how to make a miniature concrete gothic window lamp and while I do love the look of the concrete it was a pain to work with.





I had to cast it three times because it would crack during demoulding or simply refuse to come out of the mould destroying the part in the process...plus I had to wait a few days everytime before it has cured enough to handle.



As I wanted to make more of these types of lamps I started trying out some different methods which led to this Instructable, I can now make up to 3 per hour with a single mould!




If you enjoy my Instructables and would like to support my future projects you can Buy Me A Coffee.


Supplies:

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To make your own you will need the following:




  • Access to a 3D printer

Amazon - Creality 8K Resin 3D Printer HALOT-MAGE PRO

  • Beta plaster

Amazon - Perfect Cast

  • Black pigment

Amazon - HAWINK Tattoo Ink Set 

  • 5mm Candle LED

Amazon - 100pcs 5mm Yellow Flicker Flickering LED Diodes

  • 100ohm Resistor

Amazon - 100 ohm Resistor 1/2w (0.5Watt)

  • USB Cable

Amazon - Braided USB A to USB C Cable

  • EVA Foam sheet

Amazon - Black Foam Sheets Crafts

  • Hot melt glue kit

Amazon - Hot Glue Gun Kit with 30 Glue Sticks

  • Chrome marker

Amazon - LET'S RESIN Liquid Mirror Chrome Metallic Markers

  • Paint

Amazon - Testors Acrylic Value Finishing Paint Set

  • Polycarbonate/Wood/Cardboard for the mould

Amazon - Adjustable Mold Housing Kit




*As an Amazon Associate I receive a small percentage from sales made through provided links at no cost to you, this helps fund future projects.

Design & Print:

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To make the door and LED holder I turned to 3D printing.



I jumped onto Fusion 360 and started with the door. The one in black door pictured above I left it very plain and it was already hinged open, this meant it had to be printed with a lot of supports, took three times longer to print and ended up warping whilst printing as some supports came loose.


I ended up making it lay flat on the bed with hinge cut out that can be heated up when you're done with the lamp and simply bent open, I also added more details to the door like the mail slot.



I also ended up printing a little envelope prop that fits into the mail slot, this got me thinking of all the personalisation you can do to make this a great little gift...house numbers, a wreath for Christmas, some Halloween décor!



The centre mould is simply a rectangle the same size as the door frame with some round corner supports that need to be cut off after printing, this is to prevent any warping of the sharp corners while printing.

Making Your "Concrete" Wall:

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With our mould inner printed we can now cast the "concrete" wall.


The plaster I'm using for our imitation concrete is an industrial beta plaster that is specifically made for casting models and is basically plaster of paris with added plasticizers to give you very durable castings. As the plaster is an off-white color we need to add a pigment to give it that concrete look, the one I'm currently using a lot is...tattoo ink! Black tattoo ink is basically just super fine charcoal powder in a water based suspension, it is a very concentrated pigment, safe to use and easy to get off your hands.



Using some hot melt glue I started by adhering the printed centre piece of the mould onto a piece of discarded polycarbonate sheet. I then cut a long band of polycarbonate into four pieces that I will make the mould outer walls with.



Now once again using some hot melt glue form your outer mould, you can make this as wide as you want but mine is about 30mm around the inner printed mould and about 20mm from what the bottom of the door will be. Make sure to seal all the outside seams of your mould with the glue to avoid the plaster mix leaking out whilst curing.



Time to start casting!


Mix up a batch of casting plaster according to the manufacturers specifications, with mine I simply had to add water until I had a thick slurry. Now we need to color the mix by using some of the tattoo ink, I ended up adding approximately 10 drops and it looks identical to classic cast concrete just remember that it does dry lighter but darkens again when sealer is applied.



The plaster I used was ready to demould after only 20 minutes, and it was such a breeze to work with it just popped out clean and the casting is super strong.


Take note though that although the casting is cured it still has a lot of moisture inside so I recommend leaving it outside in the sun while you finish the rest of the lamp before sealing.



Now that your casting is cured and dry we can move on to sealing it to protect it from scratches and return that deep concrete color.


For the sealing I simply mix some PVA glue (wood glue) with water 1:4 ratio and apply it with a brush.

Painting:

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We can now start painting our 3D printed door.


Because I used clear resin to print the door I started by painting the window panes with clear lacquer that has some blue tint added to combat the yellow of the resin, this clears it up and gives a beautiful glass like look.


To that realistic metal reflection I painted the door knob and mail slot using a chrome marker. Unlike those shake can chrome sprays these markers give a very shiny chrome effect on low wear parts, they are also available in gold and copper.



Next because red likes to bleed into lighter colors I went ahead and painted the door next, you will want to let this coat dry completely before doing the white to prevent bleeding.



Now you need to properly clean your brush (preferably use another one) and swap out the cleaning solvent...I started without pouring in new solvent and got a pink frame.

With a fresh brush and solvent I started painting the door frame, window frame and envelope in white.


Once your paint has dried you can go over the edges to clean up all the messy parts and attach your accessories.

The Electronics:

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The electronic part of this project is super simple consisting only of resistor hooked up to three LED's and a snipped off USB cord to provide power.



I started by soldering the three LED's in parallel with each other, then snipped off the excess of the positive leg against the solder point and soldered the 100ohm resistor to it.



Next we need a power cord.

I bought these beautiful braided cords at a clearance sale because of the outdated connector, luckily we only need the USB-A side so I snipped the other end off and cleaned the wire.

We will only need the positive (red, +5v) and negative wires (black) so you can cut the green and white signal wires off.



Now we can press the LED's into the holder then feed the USB cable through its support and solder it onto the LED's, red to the resistor and black to the negative leg.

Assembling Your Lamp:

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With the door painted we can now assemble the lamp.


First I glued the LED holder in the bottom corner where the doors hinge will be, to glue all of the printed parts to the casted plaster I use high viscosity CA glue along with activator.



Next it's time to glue the door in place, I placed it about 10mm in from the front of the plaster frame. Because the resin I'm using is flexible I had to start glueing at the bottom and bend the frame into place whilst moving up.



To cover the back of the door and protect surfaces you will put your lamp on I went with some EVA foam. These foam sheets can be found at most craft stores and usually come in packs of 10, they are super cheap and so versatile.



I cut out a piece just slightly smaller than the plaster cast with a sharp hobby knife then just made a slit where our USB cable can slip through.

To glue the EVA foam to the plaster I use a clear all purpose contact adhesive.

Enjoy!

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I hope you guys find this Instructable useful and if you have any questions please feel free to leave me a message or comment bellow.



Thank you for taking the time to read through my project and as always..


Happy making!