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Coco
13-09-2009, 10:45 AM
So I was looking at casting grain on cookson's site and apart from thinking how beautiful it is :<3: I also got to wondering about how you work out how much you need to buy. It's probably glaringly obvious and I'm being mega stoopid - again but right now I'm stumped. Is a gram a lot or does it just work out as something like 3 grains? #-o :help:

bustagasket
13-09-2009, 10:55 AM
i wish i could help but i dont have a clue about whar you are on about :(

mizgeorge
13-09-2009, 11:30 AM
LOL! A gram really isn't very much at all!

There are lots of displacement tables around (Tim McCreight's Complete Metalsmith springs to mind), to help you work out how much metal you need by weight after you've measured the volume of a model, but to help imagine what weight something is, it's sometimes easier to think in terms of known quantities - a pack of butter, for example is 250g. Equally, a sheet of silver 1mm thick and 5x5 cm in size weighs just under 26g.

For those of us old enough to still think in imperial measures, there are 28g to an oz, and 31.1g to a troy oz (the traditional unit of measurement for precious metals and gemstones).

Not sure if I've made it any clearer now!

MuranoSilver
13-09-2009, 11:32 AM
Su
Casting grain (http://www.cooksongold.com/Grain-and-Casting-Pieces/Sterling-Silver-Grain-prcode-ASA-000) is what is melted to pour into moulds and make stuff (like JasonJohns been doing).
You can also cut up scrap metals and just melt that.
Sorry Coco not sure of the grain sizes but if you weigh a bit of your silver, the size you'd like to make something in it will give you an idea of how much you'll need. Don't forget to add some extra on for the sprue and pouring area.
Nic xx

Coco
13-09-2009, 12:06 PM
Ooooh, yes that sounds like a much better idea than random guessing! :ta:

Lindyloo
13-09-2009, 09:08 PM
I was told once by a tutor that when melting scrap gold, you should add some casting grain to improve the purity and prevent it being too brittle. Does the same apply to melting scrap sterling silver?

bustagasket
13-09-2009, 09:13 PM
Su
Casting grain (http://www.cooksongold.com/Grain-and-Casting-Pieces/Sterling-Silver-Grain-prcode-ASA-000) is what is melted to pour into moulds and make stuff (like JasonJohns been doing).
You can also cut up scrap metals and just melt that.
Nic xx

Ty hun, i will get the hang of this in the end lol

Matp85
14-09-2009, 07:56 PM
hmmm as a caster you need to know the weight of the item you are going to cast then convert it to the mental weight.

conversion tables can be found but i know most of the precious metal conversion off by heart, so if you know what the item is made of plus what you want it to be in just ask!