Thinking about making large sculptures. Any tips?

Great! We're thrilled you want to go BIG!

This can be done over polystyrene foam, cardboard, foil, metal lathe, chicken wire and other materials. 

Pal Tiya Premium is an excellent sculpting material for large scale pieces and can easily be combined with internal armatures to create amazing pieces.  

PTP is primarily used as a hollow shell material. On larger sculptures, an internal supporting structure is needed. This can be either steel or internal cross sections built of PTP. 

Steel: Rod, bar, lathe, stainless or galvanized. Necessary for over human height applications, very large pieces, or sculptures with components that extend significantly off the surface. Seeking advice from an experienced welder is recommended. Rebar has a tendency to rust if moisture is propagating through the piece. We recommend spray galvanizing the metal as a precaution. Fully cured and sealed PTP sculptures are naturally resistant to moisture permeating the material.

PTP cross sections: These need to be 3/4 inch thick and be positioned to transfer any additional weight applied to the shell to the ground. Often a series of interlocked internal cross sections. Mostly for simple, ground based and non-suspended pieces. 

When using steel, the interior armature must connect to the PTP shell. Otherwise, the armature offers no support over time. Foil will disintegrate over decades within the piece, potentially leaving an armature rattling around inside not doing any good.

This connection can be done by directly encapsulating some part of the wire, steel or lathe. If the sculpture is to be climbed on, or suspended over head height, significant portions of the shell must hang on to the metal. This transfers the weight from the shell, through the steel, to the ground.  Connect the shell to enough steel to support this additional weight any place you feel could be compromised; whether it is an arm sticking away from the body, or where a foot hold could be used for climbing.  The armature must be strong enough to support the weight of the entire piece on it's own 

Large sculptures typically need a forklift to carry them. If using foam, the underside may be crushed by the tines. This will cause the sculpture to tip and make transporting it troublesome.
There are several ways to prevent this:
1) Carve two channels across the underside for the tines to slide into, and coat the bottom with 1/2 inch (12 mm) of Pal Tiya Premium. This makes the base into essentially a permanent pallet. It also allows for lifting straps to be placed underneath. Very important when your piece is lifted and placed by a crane. 
2) Add more PTP around the bottom outside edge till solid 2 inches thick (minimum) and 4 inches high. This makes a stiff and extra resistant rim so, if lifted by straps, it doesn't crush the thin shell. 
3) Do both. This is how we've constructed all of our large pieces and makes them as strong as possible, easy to carry and simplifies the installation by providing an in-built foundation. This is a great selling point for a sculpture. In-built foundations save a lot of installation costs for the client.
4) On very large surfaces to be climbed on, reinforce any suspicious areas with a thickened channel cut deeper into the foam. This will become an internal supporting rib once filled up with Pal Tiya Premium. Under climbing surfaces parallel to the ground, the reinforcing rib should have a component that reaches down all the way to the ground. This safely transfers the weight of anyone standing on the piece from the shell to the foundation.
5) Pre-made concrete pallets can also be incorporated into your piece. This application works well for very large cardboard/foil sculptures which have small footprints, overly tall, oldy balanced, or have no foam to carve grooves into. Pallets are essentially low tables, 2 inches thick and 4 inches in height, with three parallel beams across the bottom. These uprights provide spaces for forklift tines to slot into for transport.  Pallets can be easily manufactured in advance to your desired size/sculpture. They do require metal lathe/chicken wire/rod mesh embedded within the wide surfaces into the upright legs. They also require several 2 inch attachment holes in the top for binding your sculpture to them.  Making them with standard fiber reinforced foundation concrete at your local hardware store is recommended.