Saturday, 17 July 2010

Plaster Cast Experiment concludes after 20 weeks

When things around you start crumbling... the plaster cast evaluation experiment of 2010...

At the start of March, a week before Jon and Corinna went to Texas, we decided to check the ability of some builder's plaster to form a cast of impressions in mud, in case Jon wanted to immortalise any tracks while in Texas.

I wetted some sand and then, for testing purposes, pressed a skull into it. Then withdrew it, and poured plaster in.

We weren't very impressed to find that, on the day that Jon and Corinna left the UK, it still wasn't dry. Easter came and went, and then the MayDay holiday... and it was still soggy.

I just left the tray to do its own thing, just to see how long the stuff really did require to dry. In June, it reluctantly summoned up some rigidity, and a couple of days ago I plucked the firmly-set plaster cast from the tray of sand and left it on a nearby bin, to let the July rains wash the sand off.

The next day, I found a crumbly pile of soggy gunk, that looked like a heap of guano.

So, a long-running evaluation of this potential CFZ resource finally came to an end after 20 weeks, and my official verdict on it was not very polite, when I told Jon about it.

Interestingly, Jon suggested we keep the rest of that bag of cement "in case it comes in useful, one day."

Perhaps we can run a CFZ competition one day, and find out the Top Ten best uses for the stuff. In the meantime, it's up in the workshop, if anyone wants to put in a bid for it!


stormwalkernz said...

Graham have you tried mixing a little sugar in the plaster mix, this arraently makes it set quite quickly and gives it added riigidity.
I used to make plaster sculptures and found it very relyable.

Tony Lucas

stormwalkernz said...

just a thought but has anyone tried expanding foam a it seems to follow the contours well - an experiment I got planned for the summer.

Dale A. Drinnon said...

When I started out doing investigations into Indian Bigfoot tracks in the 1970s, the first set was in the wet gravel of a creek bottom. We later ascertained that the tracks had been faked, but my frst attempts at making a plaster of paris cast of a likely footprint came out as another pile of guano, as you described. In more recent years I tend to favor paraffin for quick results although the casts you get in that case are much less durable (You can always recast from those at a later date, I am told)