Hessian/ burlap/ crocus composites

2017 Jun 28
#composites  #pureImagination  #mold 

To make the composite surface, I will combine hessian with a two-part resin which takes about thirty minutes to set and five hours to cure. This job is messy business and I did not have gloves or time to get gloves. That was a bad idea, first, not many photos. Second, the resin gets very hot in just a few minutes, trial by fire. Finally, it is nearly impossible to get off your hands. After countless soapings, I resorted to scrubbing my hands with coarse hair brush/ soap combo and then wearing (different) gloves for the next few hours because my fingers were too sticky. Do not do that.

This is how the molds work. It is difficult because there is a lot of curvature on a small surface. There are better ways to plan cutting patterns to optimize the positioning of the material when wrapping the form but I am just going to dive in and cut on the fly.

Approximately cut a couple pieces of material to the size of the form.

Mix the resin. This one is 3 parts A to one part B. Mix thoroughly.

Then begin spreading the resin through the entiriety of the fabric.

Through the next couple steps my hands were too messy to take photos. Effectively, I wrapped the inner portion of the form with the resin soaked crocus. I ensured all the form was wrapped in two layers because in previous prototypes in our lab, we found 2 layers to be a sufficiently hard composite. As I wrapped the form, I cut away triangles of material, otherwise known as darts. Admittedly, it was a bit rushed and for the next iteration, I will plan the material preparation to greater effect. Finally, I put a little plastic wrap on the surface of the outside portions of the form and sandwiched the burlap wrapped inner form. At last, clamps.

After about 18 hours I opened the mystery box and cleaned away the plastic wrap. Not bad. The resin was squeezed between the seam of the form.

The released piece. Here it can be seen how the material was not optimized to the formwork in some locations. Also, for the inside piece, I should have had one additional piece of form to squeeze the the material to the inner walls.

I used a scroll saw to trim away the excess. Hard as a rock.

I will post links to resources I have found helpful here.

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