Prostate Cancer Awareness Sculpture

This is a piece of public art designed to raise awareness of prostate cancer in a playful and slightly shocking manner. The hand is posed as if ready to perform a gentle digital rectal examination on an unsuspecting member of the public who accidentally sits down on it.

Prostate cancer is a common and potentially very serious disease. In the USA, it's the second most common cause of cancer-related death among men. Unfortunately, many people are reluctant to discuss it openly and even more reluctant to get tested for it. With this little installation, I'm hoping to at least get people thinking about it.

The sign reads:

Don't let prostate cancer catch you by surprise
1 in 6 men will be diagnosed with prostate cancer.
1 in 36 men will die from it.
If you're male and over 50, ask your doctor about testing.

So far, I've only made one of these sculptures and installed it in the city of San Francisco, CA. I'd be delighted if other people joined in and made their own sculptures in their own home towns. Let's get people talking about rectal exams!

For full instructions, read on.


A few thoughts on the wording of the sign

I wanted to choose a few key facts that would grab people's attention without overloading them with information. I intentionally chose not to say, "if you are n years old then you should get screened."

While prostate cancer is extremely common, it varies hugely in its severity and need of treatment. The benefits of widespread prostate cancer screening are unclear and controversial. Perhaps surprisingly, there is no evidence that indiscriminate screening leads to any reduction in mortality and it certainly leads to an increase in painful and expensive medical treatments which often later turn out to be unnecessary.

However, certain people are at more risk than others. If you have a strong family history of prostate cancer or have been suffering from any its symptoms and are between 40 and 70 you should consider getting tested. You should certainly have a discussion with your doctor about the merits of testing. The test consists of a simple blood test (prostate serum antigen or PSA*) and a socially awkward but usually painless rectal exam. It might not sound pleasant, but it could save your life. As many surgeons will tell you, "If you don't put your finger in it, you'll put your foot in it."

(*this whole art installation could be thought of as a PSA PSA)

As this was just a one-off prototype, I decided to make the hand out of plaster poured into a disposable alginate mold. I originally planned to make the accompanying sign by printing onto and then laminating card, but at the last minute I came across a convenient laser cutter that let me make a much more official-looking acrylic sign.

For the hand sculpture:

• Plaster of Paris (or, even better, hard plaster)
• Dental alginate
• Vinyl glove
• Cardboard
• Plastic bag
• Adhesive tape
• White primer
• Blue latex paint
• Masking tape
• Enamel varnish

For the accompanying sign:

• White acrylic (1/8" thickness)
• Blue paint

Also helpful:

• Mixing bucket for alginate and plaster
• Laser cutter
• Fine sandpaper

Using cardboard, I made a box just large enough to fit my posed hand into without touching the sides. I then lined this with a plastic bag to make it watertight.

Dental alginate is fantastic stuff. When you mix it with water, it forms a thick gunk that rapidly sets into a flexible and slightly damp-feeling rubbery material, capturing all the fine details of whatever it's in contact with. The setting time varies from seconds to minutes, decreasing if you use hotter water or a lower water:alginate ratio.

I poured 4.5 cups of water into my mixing bucket, then sprinkled 3 cups of alginate on top (as with plaster, always add alginate to water rather than water to alginate). As I was going to be getting covered in alginate anyway, I used my hand to mix up the alginate and squeeze out any lumps and stir out any bubbles.

If you're trying this, be warned: you don't have much working time before you're left with a mixing bucket full of solid rubber!

I quickly poured the alginate into the lined box and plunged my gloved right hand into it, posing it in the position of someone performing a digital rectal examination. I then held my hand in that position for ten minutes, while the alginate set. Note that it's usually considered poor practice to hold one's hand still for ten minutes while performing an actual digital rectal examination.

I could tell that the alginate had set by prodding it with my free hand and gingerly wriggling my submerged fingers slightly to see if they came free from their surrounding material.

Once I was certain the alginate had set, I wriggled my fingers loose and gently withdrew my hand from block of alginate, leaving a negative mold of my hand.

To estimate how much plaster I'd need, I half-filled a large measuring jug with water and submerged my hand to see how much water it displaced. I then mixed slightly more than the required amount of plaster and water, according to the instructions that came with the plaster.

Remember: always add plaster to water, not vice versa.

I then poured the plaster into the hand-shaped holed in the alginate. To get rid of any bubbles, I tilted the mold to various angles and, since I'd already used my hand to mix the plaster, put my hand back inside the mold and probed its nooks and crannies with my fingers.

I then left the plaster to cure.

With the plaster set, I stripped away the cardboard and the plastic bag to reveal a rough cuboid of alginate.

I then pulled this apart bit by bit, taking care not to put too much stress on the plaster contained within. Eventually, I was left with a plaster copy of my hand. Evidently I hadn't eliminated all the bubbles in the alginate and the plaster, so the result was slightly wartier than my actual hand.

The various imperfections in the copy of my otherwise perfect hand were fixed with a little bit of sanding, re-plastering and sanding again. I also trimmed the base of the sculpture using a saw.

To paint the hand, I first sprayed on a layer of white primer.

Once this had dried, I masked off everything below the edge of the glove with tape and added a layer of blue latex paint to give the appearance of a latex glove.

I finished off the sculpture with a layer of clear enamel varnish to protect it from the elements.

I designed the sign in Adobe Illustrator, saved it as an EPS file and used an Epilog laser cutter to engrave it into a sheet of masked white acrylic.
I then sprayed blue paint into the etched surfaces, let it dry and removed the masking to produce a blue and white plaque.

If you do decide to build your own one of these, it will probably be much easier to just print out a sign onto card and laminate it to protect it from rainfall.

Now that I had my sculpture and plaque made, I needed a way to attach them to a public bench.

To avoid being accused of outright vandalism, I wanted the sculpture to be firmly attached but removable without causing any damage to the bench. This ruled out most adhesives, so I decided to mount the sculptures on pieces of plywood and use zip ties to attach them to the bench.

I traced the outline of the sculpture and the plaque onto the plywood, then cut out the pieces with a jigsaw. I drilled holes for zip ties and used a Dremel to cut channels for the zip ties to lie in, so that the wood would have a flush surface. I drilled and countersunk holes for screws to attach the plaster sculpture, but just glued the plaque in place to its own piece of wood with epoxy resin.

Now that I had my finished sculpture and plaque, I just needed to find somewhere to install them in the wild.

This bench was in a suitably scenic spot.

Here we have an official looking public service announcement installed for passers-by to see. Let's hope it reminds a few people to get tested!

And let me know if you see it in real life or if you decide to build your own!