Looking for bulk sources of chemically pure sulfur

[SkepticJ]

For the last several months I've been trying to locate sulfur in bulk so I can try out something called sulfur casting (lost-wax casting using liquid sulfur instead of molten metal). All I've been able to find is five pound bags of something called soil or garden sulfur at nurseries and home centers. It doesn't look like sulfur though, it's a weird tan-brown color that I don't really like how it looks, and don't want to waste a good one-time-use plaster form trying out.

After opening the package and being disappointed I looked at the percentage of sulfur on the bag and it said 90%. I guess that other 10% is the stuff ruining the color from the bright yellow sulfur I've seen pictures of.

Other than at a pharmacy--which would be way too expensive to get in bulk quantities (kilos) for casting. Plus I think I'd be paying for a level of purity I don't need (I don't need to be able to eat the stuff and not have it be bad for me, just cast with it.)--where might I be able to purchase purer (95%, 97%, 99% or whatever would look like sulfur should) sulfur?

Thanks.

 

[Cesium]

You could try to purify your sulfur. First wash it in water to filter away soluble impurities. Then recrystallize it from hot toluene or a similar solvent (glacial acetic acid might work too).

I've only been able to find 90% sulfur on the shelves here in California.

 

[chemisttree]

You don't need pure sulfur to cast objects. I would use sulfur used to produce the caps on concrete cylinders used to test compressive strength. They sell the bagged version of this stuff (http://www.durhamgeo.com/pdf/msds/Capping Compund Cyclap.pdf) at Durhamgeo. SoilTest has their own brand. It will work fine for casting with the filler in it. It comes in various colors but not bright yellow. I assume that the color is a secondary concern?

 

[JGM_14]

why sulfur, there are much cheaper materials to work with?

 

[SkepticJ]

You don't need pure sulfur to cast objects. I would use sulfur used to produce the caps on concrete cylinders used to test compressive strength. They sell the bagged version of this stuff (http://www.durhamgeo.com/pdf/msds/Capping Compund Cyclap.pdf) at Durhamgeo. SoilTest has their own brand. It will work fine for casting with the filler in it. It comes in various colors but not bright yellow. I assume that the color is a secondary concern?

Huh, that looks like interesting stuff. Has silica dust in it, is that more than just a filler? Perhaps increases the tensile strength?

Actually the reason I want to try casting in sulfur is so the pieces look like sulfur does. Getting the translucency and color exactly like sulfur wouldn't be easy in another material simply by mixing in colorants. Binary resins are fine things, but I've done them for a while and want to move onto something new for the time being.

 

[SkepticJ]

why sulfur, there are much cheaper materials to work with?

Plaster, yes. Casting resins actually aren't that cheap. Sulfur's cheaper than resins and very much cheaper than metals.

 

[JGM_14]

well i guess it is your money. Metals are more durable, sulfur shatters like glass. Plaster, sulfur, and most metals can be recycled. Plaster can be baked, repowdered, and be used like the original plaster. Sulfur and metals can be melted and recasted. If weight is an issue i would go with plaster, but if looks are an issue i would go with sulfur. I have seen some beautiful sulfur crystals before. If you could recreate the transparent yellow in a casting i bet you could get a lot of money if you sold it (depending on the size, what it depicts, and craftsmanship of the piece).