Cement Clock

Hey in this instructable I will explain how I made this cool looking cement clock. I used an old broken clock for making this.It's an easy project to do.It took only couple of days to make and most of the time I was just waiting for the cement to harden.Drawing the design,mold making,mixing and pouring,sanding,fixing pieces together took a total of 4 hours most.

White cement 1kg
Card board
Old clock(or get a cheap one)
Glue
Superglue
Old x-ray film
Color pigment(yellow,brick red,brown)
Waterproof Sandpaper(80,150,220grit)
One Nut and bolt
Mixing containers and water

First step is to make a proper design with all measurements.My design is given above and to make this I needed one middle circle piece,one hexagon with a gap for middle circle and a hexagon for the final border layer.middle circle will be holding the clock mechanism and we will mark hours on the same piece.To make this piece first cut a circle of radius 4cm from a cardboard.Then cut a piece of x-ray about 2cm wide and 30cm long.Glu this x-ray filim around the cardboard circle using super glu and cut the excess x-ray.Make sure its a tight fit,if there is any gap between cardboard and x-ray use Glu to seal this,if not sealed properly when we pour our cement mix it will leak through these gaps.We also need a small center hole on this circle.To make this measure the width of the centre part on the clock(see picture) and make a paper roll with the same diameter.glu this paper roll in the middle using some glue.You can also drill the hole after the cement is hardened but it's better to do this way to avoid cracking while drilling

Next step is to make a hexagon with a gap for middle circle.To make this cut six 7×1.5cm cardboard pieces one circle of radius 5cm and a hexagon with 7cm sides. Glu x-ray around the circle as we did earlier.All smaller pieces for the hexagon are then glued on the sides of the hexagon and the the bigger circle is placed in the middle.One simple rectangle base is also made the same way.cut a cardboard rectangle with 15cm length and 7cm width this one will be the base of the mold.two 1.5×7cm and two 1.5×15cm are glued on opposite edges of the rectangle to make it a rectangle mold.if you have something similarly shaped you can use that as the mold.if you want to save some cement you can place a piece of thermocol inside the mold.for example i used 10×5cm thermocol in the middle of the mold(see picture).i used same brick red colour for marbeling.Every thing else is done same as previous steps.Pieces for the final hexagon is also made from cardboard .six side pieces are 8×2cm.but we will only use this after first pour is cured and polished

Here I am using powder Colors used for colouring wood.You can buy this from your local hardware shop .The only reason I am using this type of color insted of cement color is that the hardware shop near me have only red and black cement color which I don't need.I think any type colour that's soluble in water will work.You only need small amount of color to make the marbling effect.
First take two separate half cup of white cement,to one add birck Red color powder then pour some water and start mixing.I don't know the exact amount of water I used but we are looking for honey like consistency.Add more color if you need a darker shade.once both cement only and coloured cement mixtures are similar in consistency gently tap on sides of the cups for a couple of minutes,this will remove any big air bubbles in the mix.Then both these mixture are simultaneously poured slowly into a single cup do not mix this new batch.Then the centre circle mold is placed on a flat surface and this mixture is poured slowly to avoid air bubbles
forming.Tap lightly on sides for a minute to remove air bubbles.I only needed the centre circle about 4mm thick,but I made it twice the required thickness this way I can sand it down to correct size.
Next step is the hexagon,its done similarly but with white cement and yellow pigment.I used some weight to hold the centre circle on place.
Both the circle and hexagon are set aside to harden. I let it harden over night(10hour).After cement is cured properly i removed the pieces from the molds.I was not very careful while handling the pieces and the hexagon was broken on couple of places while handling it,but i was not ready to make another one so i used the broken pieces as part of my design.we need to make one final layer but it's done after sanding these two piece

Next step is to sand the pieces down to required size.Place sandpaper on a flat surface and wet the paper with some water.start sanding with 80grit paper this will remove lot of material fast,once you reach near required size change the 80grit to 150 grit and finalise 220 to make the surface smooth.my middle circle is 4mm thick and the hexagon was about 7mm.
Next step is to keep the broken pieces as part of the design and make a final outside layer.this layer will hold the broken hexagon and also provides a unique look.to make the hexagon first glue the 6 previously cut pieces(8cm×2cm)as in the above picture place the broken hexagon pieces inside this.Next cut another piece of x-ray and glue this over the previously made inner circle.This will prevent cement mixture from covering the inner circle.because we need this piece to be 4mm thick to fix the clock.seal any holes and gapes with glue.This one is then placed in middle of the new mold.I didn't made a hexagon base for the final mold insted I placed all this on a thick plastic sheet with paper above it and this one is glued on place and secured using thermocol.you can skip this step because the paper was strong enough to half the hexagon together after pouring.I mixed white cement with brown pigment to make the final layer its done similarly as the previous steps but no second color was used so no marbling.Let the cement dry for 12 hour before sanding.Once cement is hardened sand the front side with 150 and 220grit sand paper and back side with 150 grit paper.T he base was rectangle so I sanded the edges with 150and 220grit to make it more curved,this will expose more marbled pattern and its better than plain rectangle

Next step is to mark the hour positions. I used a protractor for this.once I decided which way the clock will be sitting I placed the protractor parallel to bottom side and marked hour positions on every 30°.top most marking is 12 and after every 30° next hour is marked (see pictures)Next I fixed the clock body behind using glue use hot glue for this it will secure the clock in position.it doesn't mater if it's tilted or not since we will adjust the time later.Attach all clock hands on position start with hour hand then minutes and finally second hand is attached.to set the right time first point all the hands to 12 and then use the time adjusting knob behind to set the correct time.

Final step is to attach clock to the base I used a small screw and a bolt for this.i made a small hole on the bottom side of clock and secured a nut inside using super glu and a hole is made on the base also the screw is then passed through this hole and tighten to secure the clock on place.I was not sure about its strength so later I ended up using super glue also.
Now put the battery in and you are done.
Doing this you will always get unique designs and you can try different colours and shapes. Its really an easy project to do and try making one of your own