Recommended resin thickness on a life sized status cast around a metal armature?

Question

Project: To make a life sized statue of Freddy Mercury in black marble effect casting resin (Two part epoxy, 1 to 1 by volume).

Process: A clay statue has been sculpted around a mesh armature, and a standard box mold has been created using the clay statue. This has been completed.

A welded rod skeleton will be placed inside the mold, the skeleton will be load bearing, and will allow easy mounting of the finished statue to a plinth, and for the attachment of the arms and head, which are being made separately. This has been completed.

The body of the skeleton will be wrapped in a low grade fiberglass material and coated in a two part resin which will harden around the skeleton further strengthening it, and filling up space inside the mold with a material that is lighter weight than the marble resin to reduce the overall weight of the statue. It is also cheaper than the marble resin, reducing the overall cost to produce.

If a thick layer of fiberglass is used (with additional material packed underneath it to pad it out) there will only be enough room left inside the mold for a thin outer layer of marble effect resin.

Conversely, if only a thin layer of fiberglass is used (with no additional padding underneath it) there will be more room inside the mold for a thicker layer of marble effect resin.

This has not yet been completed, but is a method that has previously been used for 1/4 scale sculptures with good effect.

There will be over a dozen separate pours involved.

Question: should the "padding" around the skeleton be kept to a minimum so as to allow a thick layer of resin as is technically possible(For example, 1-2 inches on the body and legs), or should it be heavily used so that the resin forms only a thin skin on the surface of the statue (For example, 1/8 - 1/4 of an inch) with the bulk of the statue consisting of fiberglass over an armature?

Or is there a good in between level?

The manufacturer recommends a maximum thickness of no more than 2 inches. In practice a thickness of over 1 1/2 inches will may not be practical due to the number of pours required, so as to not put too much stress on the mold.

The resin is purely a decorative finish and is not load bearing.

Answer 1

Since the resin itself isn't load bearing, you should try to reduce the amount of it as much as reasonable. Adding more resin to the statue adds considerably more weight wich may overwhelm the capacity of the armature or other parts of the resin which have to support protruding details.

Comparing the thicknesses of different resin objects I'd say 1/8th of an inch is too thin. That is basically a thin sheet of resin that I'd mostly use for jewelry or "stained glass" resin objects. It feels fragile, though I personally never broke one. However, air bubbles or irregularities in the mold and padding could reduce the thickness even more, leading to gaps or fragile areas.

1/2 of an inch feels more secure. That's a thickness you find in resin coasters, lamps and other artworks like bowls and wall decorations. These objects can support their own weight and don't break when handled roughly. The statue should easily be able to withstand someone (or something) bumping into it without damage.

1 inch thickness or more feels like a waste to me. It adds a lot more weight (and cost) to the statue without any perceived benefit. Since your resin is black, you won't even need the thickness to achieve full coverage of the stuffing.

One last word about the padding: I hope you pack or secure it tightly enough to the armature that it cannot shift or rotate around the metal rods. If not, you create something like plate tectonics with the potential to fail spectacularly. If the resin "floats" on a layer that can shift around or that is only attached to the armature in very few places, you might damage your stature during transport or installation.