Making Latex

I am going to attempt to make large coloured latex sheets to use as a membrane over the large 12" PA speaker that I have to create XXL paint sculptures.
I am going to use Gedeo Latex and add colour with Barnes Coloured Pigments and then wrap the latex around a frame.

I started off by testing the latex and making sure it would function as wanted.  I mixed a small amount with some BJB Black pigment and then evenly spread it over a piece of glass.  I got a thin plastic sheet and carefully rolled it down over the latex and smoothed it out to ensure both sides are of even thickness and smooth.

The latex came out quite smooth but was not quite as thick as it needed to be and was uneven, but it was extremely stretchy and would work if it was more careful.

I decided the easiest way to make a large piece of latex was to make a mold out of plaster.  I got a large frame and taped it to the middle of a large piece of corrugated plastic sealing the corners and sides.


I mixed up a large amount of plaster and slowly poured it in to make sure there were no bubbles.

I got a larger piece of plastic sheet and rolled it down over the wet plaster to make it really smooth and push the remaining air bubbles to the side.








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When the plaster dried it had some patches where there were a lot of air bubbles which would make casting latex very bumpy and inconsistent.  So I mixed up another batch of plaster and did a better job of removing bubbles and laying the plastic sheet level on the wet plaster.


















The plaster dried and came out very smooth and even compared to the first try.

I mixed some black pigment with the latex and spread it over the plaster.







I rolled it out with the large piece of plastic and evenly spread it over the surface.
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After two days the latex was completely dry, I peeled the plastic off and rubbed flour all over the top and on the underside as I peeled it off the plaster to stop it from sticking to itself.

I stretched the latex over a frame and stuck it down with masking tape.  The latex had quite a few small bumps that would might show in the photos, but the whole sheet was a very even thickness which would not rip.

The frame turned out pretty good.  I stretched the latex so that the smoother side (the side that molded to the plastic) was on top and would be seen in the photos.