This week I played around with composites and wanted to make one mold to the inside of a mug. I covered the mug in saran wrap first before layering the burlap. The cutting of the burlap was a lot of trial and error to get pieces that would curve and the pieces ended up looking like circles but with four small wedges cut out. I offset the layers to make a smooth surface.
I mixed the epoxy, with a 2:1 ratio of the large container to the small container, and soaked the fabric in it. I then removed the excess epoxy and placed a bleed layer over it. The bleed layer was saran wrap but with numerous small holes made by a roller with sharp spikes to let excess epoxy escape.
I then placed a breathe layer over it to absorb that excess epoxy, and then another layer of saran wrap over that. I placed this all in a vacuum bag and left it overnight.
I removed the bag and the other layers but the composite was stuck to the inside of the mug. It was impossible to take it out and this was a huge oversight. Next time I make a composite I will be sure to make it on the outside of the material instead of the inside.