The process of building our final forms involved a process of casting all the “pieces” of our iterative tiles in order to vacuum form the various mold sections. Each of these castings, pre-vacuum form, provided an opportunity for further editing and refinement.
Speeding up the drying process. This works great for items which are simply acting as molds for vacuum forming. We did see some hairline cracking which would concern us for final product curing.
The oven drying permitted sanding within 2 hours of casting. Oven drying was done at 225*F. Sanding provides a uniform fit between mated-halves and a variance in surface between the inside- and outside-faces of the core tile.
The four aspects of the core tile’s mold. The top two have been sanded smooth and for the interior of our tile, the hub side. The bottom two are the front and back faces of the core tile and still retain much of the hand-tooled “brain” texture of our earliest exploratory castings. The brain texture has undergone a level of refinement in that each stage of vacuum forming (two prior to this final) removes a level of micro-detail.
Given the sheer number of vacuum form iterations we’ve gone through we began reusing sheets to reduce costs. We noticed that there may be a brittling effect to this so beware the fragility of reused PETG.
Even the reused PETG provides a clean final form. the plaster here is waste.
The PETG form is then nested in MDF to which it is glued into a solid assembly.
The voids between the PETG form and the MDF armature were then filled with an expanding poly foam insulation. This effected to lock into place the PETG parts which would allow the core pieces to be cut apart for post-cast disassembly while maintaining a consistant realignment.
The mold for our hub tile clamped to glue the PETG and MDF components to each other.