Introduction: Makng a Concrete Gecko (7.5m )
I was commissioned to produce a concrete model of a gecko for a new housing development.
I am a sculptor,working in wood, steel , bronze , plastics and concrete.
For this project, I did quite a bit of research into high strength mortar mixes ( no stone , just sand / cement )
Step 1: GECKO Underwoodisaurus Milii
First , catch a gecko. This fellow helped out for a bit. Then I made a maquette...
Step 2: Maquette
Carved in foam and coated in acrylic plaster and finishing cloth ( fine chopped strand mat )
Step 3:
sketching with 10 mm steel rod
Step 4: New Studio
Using a ring roller, building the body, welding intersections
Step 5: Sub Frame
Heavier steel for strength and to bond to slab.
Step 6: Internal Skin / Hessian /poly Foam Internal
I glued hessian to the inside of each half of the steel work. This was to provide a surface that could accept an internal spray-up of polyurethane foam.The purpose of this was to provide a firm surface to apply the glass and steel fibre reinforced mortar on the outside , through the layers of bird mesh.
Step 7: Reassembling the Two Halves and Chicken Wire Mesh Application
Chicken wire was stitched on to the steel rod armature. Cast concrete eyeballs fitted.
Step 8: Mortaring the 25 Mm Skin
The mortar mix was designed in consultation with a concrete engineer from Tasmania.
3 parts sand
1part Portland cement
10% Magnesium Oxide ( high early strength )
Fly ash
steel fibre reinforcing
glass fibre reinforcing
water reducing compound ( the strength of concrete is inversely proportional to the amount of water added or water-cement (w/c) ratio.
Step 9: After Curing, Acid Staining and Anti Graffiti Coating
I made 6 gum nuts in ferrocement also , to provide scale and to be used as casual seating.
Acid stain in various colours was worked into the surface and finally a coat of anti graf sealer that came from a firm called Gecko Coatings. It seemed appropriate...
Step 10: Leaving the Studio
Big test ! the gecko, weighing approx. one ton ( 1000kg ) was lifted out of the studio and trucked to its place in a playground. No cracking. The sub frame was anchored to the ground slab and a coating of rubber soft fall was put around .
Second Prize in the
Concrete & Casting Contest
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46 Comments
6 years ago
Al I'm in Perth WA. I'm looking for someone to help build a family of giant long neck tortoises. Contact me if you are interested ajarman@cockburn.wa.gov.au
7 years ago
You are amazing! Thank you for such beautiful photos start to finish!
8 years ago on Introduction
he or she is beautiful, thanks for sharing. Do you have a link for seeing any of your other work?
8 years ago on Introduction
nice job for the kids ............thank you for sharing
8 years ago on Introduction
very nicely done. too cool.
8 years ago on Introduction
thats so super cool it almost looks real
8 years ago on Introduction
Very cool!
8 years ago on Introduction
Congratulations on being a finalist in the Concrete and
casting contest! Best of luck to you! I am in love with this sculpture, just plain lovely.
8 years ago on Introduction
That is so adorable !!! I have a leopard gecko and he looks a lot like the one you made ! I want the smaller test piece you made !!!!!!! sigh
8 years ago on Introduction
Beautiful work!
8 years ago on Introduction
Wow the scale of this project is impressive. And the results are fantastic. I bet this takes the prize for the worlds heaviest gecko.
You should set up an x-ray machine so people can see your beautiful steel work.
8 years ago on Introduction
i had seen your beautiful gecko via the tec eco website-i notice that you don't include clinoptilolite in the mix? i am still trying to understand the chemistry involved and not quite sure what part the clinoptilolite plays but i thought you had used that in the mix? Also what was the proportion of the flyash, please? i have been doing some 'experimental' concrete work-mostly sculptural - magnesium phosphate concrete is an area of interest! Thankyou for sharing your construction method- especially the inner 'sleeve'- i wouldn't have thought of that.. Excellent work, very gecko!
Reply 8 years ago on Introduction
nlanga, thanks for your post. I have lost all my notes on the mix ratios, so what I put up was from an imperfect memory of it. Yes the clinoptilolite was an ingredient, but a small percentage. With the additives it was a very "short mix", so the internal foam allowed lots of pressure and vibration to compact the layup.
8 years ago on Introduction
Great job, Al. The proportions are perfect. I use a similar technique to make Living Tree Art with internal programmable plumbing systems, different type of concrete. Lots can be done with concrete. Never heard of Hessian. Looking that one up right now! Thnx!
8 years ago on Introduction
Great story for gecko to tell his buddies...."I was abducted by a huge alien, picked up examined thoroughly and strange flashes of light (pictures with flash),,,,I was released but when I went back a few days later to figure out what happened ,,,,there was this huge statue of me!!! Then it came to me,,,,they think I am a god!!!!!"
8 years ago on Introduction
This is so amazing :)
What happen to the gecko you caught?
I did not read "no animals were harmed in the making of this" :D
Reply 8 years ago on Introduction
no animals were harmed in the making of this. he was released back into the wild (my backyard )
Reply 8 years ago
Awesome!!
8 years ago on Introduction
props!
8 years ago on Introduction
Amazing!!!!! Well done and explained!!!