Hello there, my name is John, and I am from Scotland. The reason I am telling you this is that there may be some difference in what the trade name is for plaster of paris in the States, where most of your forum information seems to be based, and the trade name in Scotland. I have tried numerous outlets, building suppliers, DIY stores etc. in Scotland, and they all have different types of plaster, none of which is plaster of paris. Could anyone tell me the technical or trade name so that I could try my hand at making a half mould of a trout. Also, if anyone knows of any downloads which lists the steps to go through from start to finish for doing a simple half mold type operation I would be very grateful.
Regards, John
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The US doesn't do anything French, so it has a new name:)
if you go to the search button and type in halfcast you may get instructions there on doing your fish.
Plaster of Paris is a type of gypsum material. Although it has a specific chemical formula it still has variations in hardness etc. Then you get into other gypsum materials that are plaster like tho not in the 'plaster of paris' family. Basically - any plaster type material will work. Some are harder than others and those are generally better as they can hold sharper detail without wearing down as readily. Some of the best plaster is the detal variety. Most generic 'plaster of paris' types are rated around 2000 lbs hydrocals at 8000-9000 but Denstone brand which is used to make dental casts in denture making is rated up around 18,000 pounds or so! Look around in your telephone book and try to find a dental supply outlet and ask them for some really hard stuff. If you just want to play around tho, grab some cheap plaster from a craft store or DIY store.
I HIGHLY recommend that you purchase the book Museum Quality Fish Taxidermy available from WASCO. It is full of information and tonnes of photos and gives a lot of information on how to mix and work with plaster and walks you through every step of molding a fish using plaster. It also follows up with casting in fiberglass and painting!
The generic is "calcined gypsum". Plaster of Paris was first made in Paris, France where gypsum stone was heated hot enough to drive all moisture out which turned it to white powder. Once water was added, the slurry quickly heated and returned to its near natural state.
Thank you for your responses, they were most informative, particularly the one about the FROGS from Bruce.
Regards, John
What george said is 100% it is alos known as Molding plaster and used by artists that cast very large statues,you may want to contact those and also knows as Hydrocal.White plaster Etc.Dental technicians use also.
Hydrocal, dental plasters, and plaster of paris are all different - it's not the same stuff. Dental technicians for example do not use the sort of pottery plaster you find in hardware or DIY stores.
They are all gypsums, but they are not all 'plaster of paris'. They have different formulations and different properties. Depending on the project - some are better than others. Dental plasters are among the strongest of the gypsums, but molding plaster/plaster of paris wicks away moisture from porcelain slips better than does hydrocal or dental gypsums.
I was just hunting for similar items myself. So if I am not too late for your project then try http://www.notcutt.co.uk. also if you want to make a rubber type mould enabling you to make more than one then try http://www.mouldmaking.freeserve.co.uk (dont bother with a peek at the saucy body moulds cos you have to pay for the privilage and wont find out until you get to the front door! hahaha) Some resins are really great to work with and the detail is great! Hope you success! Linda