Poincare Clock

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Project by AffineCreations posted 12-07-2012 09:17 PM 2688 views 16 times favorited 12 comments Add to Favorites Watch

This is a project that had a long time from initial inspiration to final realization.

The wood is Curly Maple and the final clock is 12” in diameter. The main things I had to figure out was how to route the pattern of curves on the face and how to color the Maple so its nature chatoyance comes out and at the same the colors are bright.

The thing that makes the routing tricky is the changing radii of the curves from top to bottom. Having this up/down asymmetry I feel is key to the design; it needs to have this visual heaviness at the bottom. But this meant I couldn’t just set the distance once for the router. The router is attached to a swing arm with holes drilled at the corresponding radii. I take advantage of my INCRA LS positioner and mount a pivot for the arm on the fence. The clock face rests on the circle cutting jig at the other end of the table. I set the radius for any given curve and now use the 1/128” click wheel to fine tune the distance of the pivot from the clock so the V-groove bit starts and ends its curve exactly at the marked hour. This precision is important since at every hour mark, two curves meet.

On to the coloring. The first versions of this clock were painted with water-based dye and then Tung Oil used to emphasis the figure. But I (read: my wife) was never happy with how the colors didn’t maintain their initial brightness after the Tung Oil. I did some experiments and found toned lacquer would end up being bright, but since this had to go on top of the oil, a washcoat of shellac was required (water-based lacquer). This meant the color didn’t get into the wood. So bright, but no fun interplay between the color and the figure.

Continuing to play around, I came up with my current method. I paint with toned 1lb cut shellac. It does a nice job of penetrating the wood and highlighting the figure and at the same time coloring the wood. It takes a few coats to get the color bright, as the initial applications build and then some the toned shellac rides on top of the wood as a film coat. Since I’m starting with fresh mixed shellac from flake, each coat dries fast enough that I just keep making passes around the clock with each color before moving onto the next. And yes, the whole palette of 12 colors are hand-mixed from the three primaries.

Once the toned shellac has dried and been sanded back a spot, I topcoat with Target Coating’s EM6000 lacquer. Once cured, I rub it out up to rottenstone and polish with wax. The second photo hopefully gives you some idea of gloss.

Thanks for reading all the way through. I would love to hear suggestions on how this build could be improved. I will be making more.

-- - Nicholas, Silver Spring, MD

12 comments so far

View HorizontalMike's profile


7935 posts in 4405 days

#1 posted 12-07-2012 10:44 PM

Wow! What a great job of staining! Much for me to learn…

-- HorizontalMike -- "Woodpeckers understand..."

View MarkTheFiddler's profile


2068 posts in 3679 days

#2 posted 12-08-2012 12:45 AM

Love it! Your finishing technique is incredible!

-- Thanks for all the lessons!

View bondogaposis's profile


6193 posts in 3842 days

#3 posted 12-08-2012 12:54 AM

Pretty amazing, really.

-- Bondo Gaposis

View Boxguy's profile


2905 posts in 3758 days

#4 posted 12-08-2012 05:18 AM

Nicholas, what a colorful project. I have a weakness for clocks. This is beautiful and I appreciate the explanation about the asymmetrical design. Looks like you really kept at the finish process, but have it right. Thanks for sharing that. This is one of those things that looks right and makes me really work at thinking about how it was made to create the effect.

-- Big Al in IN

View rrdesigns's profile


541 posts in 4677 days

#5 posted 12-08-2012 02:07 PM

Fantastic tutorial and great clock. Reminds me of stained glass. Thanks for sharing your hard work.

-- Beth, Oklahoma, Rambling Road Designs

View BritBoxmaker's profile


4611 posts in 4527 days

#6 posted 12-08-2012 03:04 PM


by the way Acrylic Lacquer doesn’t colour at all.

-- Martyn -- Boxologist, Pattern Juggler and Candyman of the visually challenging.

View twokidsnosleep's profile


1133 posts in 4465 days

#7 posted 12-08-2012 04:17 PM

Pretty colors….. really a gorgeous clock!

-- Scott "Some days you are the big dog, some days you are the fire hydrant"

View sras's profile


6711 posts in 4620 days

#8 posted 12-08-2012 06:25 PM

The resulting shapes are so perfect most would not understand the effort to achieve this level of accuracy. Fantastic!

-- Steve - Impatience is Expensive

View AffineCreations's profile


28 posts in 3749 days

#9 posted 12-08-2012 06:44 PM

Thanks everyone for your comments.

@HMike, learning how to finish = full scrap bin + extra time. I am always playing around with different combinations of woods, dyes, oils and topcoats. An endless game of ‘what if…’

@Martyn, when you say Acrylic Lacquer doesn’t color, are you referring to it straight out of the can? The EM6000 is the same, until I start mixing water-based dyes into, which was the experiment with which I was playing. P.S. TransFast black + lacquer + rottonstone = Piano gloss finish. But for a future project…

@Big Al, ”one of those things that looks right and makes me really work at thinking about how it was made to create the effect” You made my day! I strive for my work to appear as an harmonious whole but to invite further investigation. And your comment suggests I achieved that with this build.

@steve, I always feel the need to explain to people I don’t own a CNC machine. When I was in NYC at the Maker Faire and got to see some CNC machines in action, I was not convinced they could route the curves as smooth as I can with a router swung by hand.

-- - Nicholas, Silver Spring, MD

View BritBoxmaker's profile


4611 posts in 4527 days

#10 posted 12-08-2012 07:05 PM

Yes straight out of the can. If you’re looking for an alternative clear finish. I use a spray version which is good at keeping the underlying colours true.

-- Martyn -- Boxologist, Pattern Juggler and Candyman of the visually challenging.

View Spoontaneous's profile


1340 posts in 4821 days

#11 posted 12-14-2012 11:56 AM

Very nice and fun clock! Sounds like a lot of work went into this. That second photo shows how well finished the clock really is.

-- I just got done cutting three boards and all four of them were too short. (true story)

View AffineCreations's profile


28 posts in 3749 days

#12 posted 12-14-2012 06:00 PM

A follow-up. I just got off the phone with a buyer at a catalog/online store about stocking this clock, along with my tool caddy and Newton coasters

She sounded very interested. Here’s hoping…

-- - Nicholas, Silver Spring, MD

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