The InstructionsPosted: February 10, 2016
In order to make the concrete lamp this is the list of materials which I have required.
Cement (I used Snowcrete- Any cement will be good but I preferred the white cement)
5mm Laser suitable plywood.x2 sheets
3mm clear acrylic half a laser sheet. (300 x 200)
5mm clear acrylic laser sheet. (600 x 400)
mitre mate wood glue (Again other types of glue could be used with the use of 90 degree clamps such as two part epoxy glue)
small screws and wood planks in order to strengthen the mould to prevent it from coming apart under the pressure of the cement.
Pre-made lamp cord for health and safety.
I have begun by making the mould. I produced the drawings bellow for the outer and the inner parts of the mould in order to laser cut the pieces for best possible accuracy, I have then butt jointed the mould together using the adhesive. when sticking the parts together using this instant glue you have to move quick because the glue sets in around 5 seconds so placing the parts must be as accurate as possible. I would recommend gluing them together against a 90 degree corner.
(LASER CUT FILES-Outer, Inner, acrylic to be continued…)
Glue the bottom acrylic piece (104 x 154) in order to give the shape for the acrylic piece which will come on top of the lamp. You must ensure that the acrylic piece to which the base is glued on to is 23mm away from the edge of the bottom. The sides on the inner mould have to be then placed in the centre, 25mm away from the edge of the bottom and glued on top of the acrylic piece, the acrylic shall be visible 2mm all the way around the inner walls.
When the inner and outer mould are glued check that all sides are flat! If not, sand all the sides on a belt sander until flat.
Cut planks of wood which will fit inside your inner mould and screw them in from the outside, this will help the mould to be held together.
Once the inner mould is strengthened glue the outside walls on to the rest of the mould using your adhesive. once all 4 sides are glued together cut wood planks to fit around your mould and screw them around your mould at the bottom and near the top. Notice that only 2, opposite sides have to be cut perfect as the other ones overlap.
when the outer and inner parts of the mould are assembled together fix the press fitted parts at the top on one side of the mould, this does not matter which side. I used the same adhesive to fix the parts to the mould. no glue is necessary for the press fitted parts. some sanding may be required to the 3 squares on each of the beams before pushing the parts together.
When mixing your cement try to use a mesh to avoid big lumps of cement from falling into your mix. This will produce a nice, even consistency and hopefully less air bubbles as well as make things easier if you are going to be mixing the cement by hand. The cement must be slightly more runny than custard in regards to the consistency. when pouring in the cement its important to shake and tap the mould to even out the cement and reduce the air bubbles. if you have an access to a vibrating table to shake out all the air from the mould contents that will ensure a better quality of the finished product.
in regards to the acrylic for the top panel and the base you can either use fine wet and dry sand paper to give the Perspex a frosted effect or you can buy already frosted Perspex which is slightly more expensive but looks better.
The next step is to cut out the acrylic parts for the base and fabricate 45 degree edges and glue them together using solvent cement.
(Files to be continued…)
(Pictures to be continued…)
The final step is to drill out the hole for the cable using a diamond drill bit (10mm ideal) as any other ones will cause the cement body to crack. Then you need to feed the cable through the main body but firstly you must remove the components from the cable to fit the cable through the hole. then assemble the cord back together and fasten the bulb holder to the body using the fixing provided.
delays on some of the steps have been mainly caused due to the cement setting time.