In this Instructable I'm going to outline the steps my partner Tina and I took when we were figuring out this build. We were hired by a film company to make a prop clock (the clock had a very specific look - that's why they didn't just buy one from an antique shop). If you need any clarification on any of the steps please leave a comment and I'll try to clear it up.
Here is a list of the materials and tools we used:
1" thick x 8" wide x 96" long smooth oak plank
various types of trim
various clock parts
1 1/4" crown staples
MoldStar 30 Silicone
SmoothCast 325 Resin
Step 1: Sketching
Let's talk about sketching. The first sketch we received was from the designer Greg Chown (you can see other work by Mr. Chown here
). Tina will take the initial sketch and make a 3D sketch (using GOOGLE Sketch Up - it's free and really easy to use!). This serves a number of purposes: we can show our client a fairly accurate depiction of what the end result should look like, we can keep a record of the build and most importantly it really helps us start to figure out what materials we will need and the angles or lengths of cuts, etc.
The sketch with the red arrows was to show our client the actual parts that we selected from a manufacturer, to get approved.
Step 2: Cut the Six Sides
We don't often get to build props using hardwood (we usually just use pine or spruce) so we were pretty stoked to be able to use oak. We set up a stop on the chopsaw so that the six sides would all be cut to the same height (12 inches).
Next, we calculated that for six sides we would need each piece to be cut 6" wide with an angle of 60o. I set my table saw to 30o (30o + 60o = 90o) and ran the pieces through. Now they should all fit together to make a hexagon.
Step 3: Joining Biscuits
OK, here's a pretty good youtube video
that shows the basics of using a biscuit joiner. I've angled the fence 60o
so that when I cut the slots on the angled sides they should line up with each other.
To make sure that the slots line up I've used a scribe and marked a line on each piece, three inches from both ends.
My oak wood planks are thick enough that I can use the largest standard biscuit, a #20. Once it's time for glue up I will likely put painters tape on the outside surface to catch any glue that squeezes through.
Step 4: Mold-making (casting the Antique Details)
This prop clock has six sides, five of which are to have ornate oval frames and corner spandrels on them. I found a frame in an antique shop that fit perfectly, but, being an antique, there was only one. No worries! We will try to cast it!
There is a great shop here in Toronto called Sculpture Supply Canada; they advised us to use the Smooth On product Mold Max 30. Because the frame is quite thin, Tina added a 1/8" layer of red wax to the back. The wax raises the frame 1/8" above the clay bed inside the plywood frame; this will create a deeper cavity in the silicone mold.
We don't own a vacuum chamber so we're hoping that the Mold Max 30 doesn't get too many bubbles trapped in it when it is curing.
Step 5: Making Fake Porcelain
Inside the brass frames are paintings on porcelain. We looked into getting tile cut into an oval (very difficult) so we decided to try to make our own.
In the photo below the thing that looks like a toilet seat is actually a small plastic bathroom mirror that I got at the dollar store. I leveled it on the 2x4s, sprayed it with mold release and then poured Hydrocal 50
on top of it. My hope is that I can pop out the hardened Hydrocal, sand it with emery paper and then treat is with a topcoat.
Step 6: Router Your Wood!
OK, now I'm going to router out 1/8" spaces to place the fake porcelain tiles and the brass etched lunar phases wheel. I'm trying to arrange the wood panels so that all the grain is "pointing" upwards; I just think it will look nicer in the end. I router out five of the panels; the sixth one needs to be routered from the back to allow the clock machinery to stay flush.
Now, I read that during glue-up you can put painter's tape on the face of your project to catch any glue that squeezes out. I've decided to try it here. As you can see in the photo with the biscuit I may have used too much glue. What I found is that the tape got in the way of me seeing what the seam looked like. I decided not to use the tape method with the rest of the joins and to just clean up the glue as it squeezed out. I'm going to sand it all down in the end so I'm not too concerned about the glue.
The seams were not as nice as I would have liked them to be. Using oak I found the crown staples didn't pull the wood together the same way it does with softer wood like pine and spruce. I've had to put ratchet straps around the piece to help squeeze it tightly together.
I was quite happy with the lunar phase graphic Tina made on Illustrator - we took it to a shop to get etched on sheet brass. Sadly we had to cut the lunar phase disc in half in order to make it fit; we had it laserjet cut before we had the other measurements so we made it too big. I had to very carefully drill very tiny holes in the face place - any hard pressure and the brass would kink.
Step 7: Trim and Stain
This part got tricky; we decided to use oak trim and the only stuff available had a lip. The lip had an angle (less than 2o so I didn't notice until after it was cut). It took some cutting, eyeballing, re-cutting and so on until the seams closed up sufficiently. Then there was a lot of careful wood filler, trying not to smear too much on the face of the clock. This was followed by A LOT of sanding, trying to smooth out imperfect edges and remove wood filler.
Once it was ready I hit it with a dark maple wood stain. Tomorrow I'll start throwing varnish on it.
Step 8: Scenic Painting the Resin Cast Details
The frames have been demolded and have hardened; they are now ready to be cleaned up and scenic painted.
First Tina will clean of any bubbles and mistakes with a dremel (she sands them on a super special sanding vacuum box
!!) then she sands the backs of each frame flat on a belt sander. While that's getting done I am spray painting the dome and the other details. Tina then starts to apply various paints to the resin frames to make them look like the original brass frame.
I glued two small wood finials together to make one super one. Then it gets spray painted to make it look like metal.
Step 9: Final Details
To finish the clock we ran it through the painting room one final time, adding more distress aging where it looked like it needed it. I cut a door on the base so one can access the clock mechanisms and adjust the time, etc. To make it easier to travel with I've attached the finials separately; they just plug back onto the clock with metal dowels. And that's it - you have an "antique" clock!