jontheron Posted February 7, 2008 Share Posted February 7, 2008 Hello folks, I am looking for any advice on how to build a rig to produce a 'rain of salt' in a line across the stage about 3 or 4 meters. It doesn't have to have a lot of volume, but there needs to be enough falling in steady stream to be seen for about 10 to 15 seconds. Our show calls for this towards the end of the play, and the set already has the floor covered about 12cm deep in salt. There seem to be several ways to achieve this, but I was wondering if anyone had attempted a sand or salt rain before and might have some pointers. The tricky bit is that the rig needs to be portable as the show is designed to tour. Any thoughts? Thanks! Jonathan Link to comment Share on other sites More sharing options...
mac.calder Posted February 7, 2008 Share Posted February 7, 2008 The most important thing with a drop like that, is you need to ensure the salt is bone dry - damp salt clogs. I would buy some flyscreen, and some wood and make a gutter like device - a bit like the illustration below: \_/ The flyscreen makes up the floor, and use the wood to contain the salt. By putting a lid on it, and attaching a cog to one end of the drop unit. Suspend it through the center axis, upside down, then attach a rope to the 9 o'clock position on the pulley, run it clockwise over the pully, and you have a basic dump mechanism. Link to comment Share on other sites More sharing options...
Seano Posted February 7, 2008 Share Posted February 7, 2008 Any thoughts? If you're touring venues with flys, either hemp or counterweight, a traditional snowbag is the way forward. They've been discussed here quite a bit in the past, normally I'd try to find a link for you, but no time now, sorry. A forum search will turn something up, you could also try a google search of the rec.arts.theatre.stagecraft newsgroup.The good news is, its relatively cheap and easy. Link to comment Share on other sites More sharing options...
kingjohno Posted February 7, 2008 Share Posted February 7, 2008 We've done something similar to this in the past. Our solution was to have a large 'gutter' for the sand/salt/etc. to be held in, then at the bottom there were 2 'sliders' with holes in. At the start they were in a closed postition, then when the effect was required we just moved one layer to the left/right and it all fell out. Very similar to 'connect 4' if you get me. Link to comment Share on other sites More sharing options...
Guest lightnix Posted February 7, 2008 Share Posted February 7, 2008 The most important thing with a drop like that, is you need to ensure the salt is bone dry - damp salt clogs.Would it help to mix in some fine silica gel to absorb the moisture (seeing as how it isn't going to be eaten)? Link to comment Share on other sites More sharing options...
kingjohno Posted February 7, 2008 Share Posted February 7, 2008 I wouldn't put it in just incase a member of the cast clips and ends up with some in his/her mouth. It can be really dangerous. Link to comment Share on other sites More sharing options...
Ike Posted February 7, 2008 Share Posted February 7, 2008 I wouldn't put it in just incase a member of the cast clips and ends up with some in his/her mouth. It can be really dangerous.Riiiight...assuming it's pure silica gel it's completely non-toxic, non-reactive, non-flammable and generally safe to do whatever the hell you want with. :P Link to comment Share on other sites More sharing options...
slipstream Posted February 7, 2008 Share Posted February 7, 2008 http://www.silicadesiccant.com/faq.html - not toxic http://www.food.gov.uk/multimedia/pdfs/evm...iumchloride.pdf - 500mg per kilo can be fatal Really dangerous is when the venue discover 12" of damp salt on their stage and work out how heavy it is. Sam Link to comment Share on other sites More sharing options...
DavidLee Posted February 8, 2008 Share Posted February 8, 2008 The most important thing with a drop like that, is you need to ensure the salt is bone dry - damp salt clogs.Would it help to mix in some fine silica gel to absorb the moisture (seeing as how it isn't going to be eaten)?I may be missing something here... but wouldn't white sand be the ideal solution? Commonly sold for play-pits at something like £125 per tonne. Also available in 25kg bags - but proportionally much more expensive. David Link to comment Share on other sites More sharing options...
gyro_gearloose Posted February 9, 2008 Share Posted February 9, 2008 I'll second sand as a better solution. Salt is hygroscopic which means it will absorb moisture out of the air, thus making it a bit pointless adding silica gel! Be aware though that whatever you use will have weight implications. A quick Google gave weights for dry loose sand of about 1.5 tonnes per cubic meter, while salt is about 1.2 tonnes per cubic meter. Since you are only going to a depth of 12cm, the weight on one square meter of stage will be 180kg with sand or 144kg with salt. For a stage 30 feet by 20 feet, assuming that you want to cover the entire stage to an even depth, you'll need 9.7 tonnes of sand or 7.8 tonnes of salt and a big truck to transport it all! Link to comment Share on other sites More sharing options...
the kid Posted February 9, 2008 Share Posted February 9, 2008 www.snowbusiness.com Should be able to help. Link to comment Share on other sites More sharing options...
Ike Posted February 10, 2008 Share Posted February 10, 2008 Salt is hygroscopic which means it will absorb moisture out of the air, thus making it a bit pointless adding silica gel!While it's true salt is hygroscopic that's the exact reason why you should add something to absorb excessive moisture. Most table salt already contains an anti-caking agent such as calcium silicate to carry out this function. Anyone know how dusty play pit sand is compared with salt? Link to comment Share on other sites More sharing options...
gyro_gearloose Posted February 10, 2008 Share Posted February 10, 2008 Silica gel can only absorb so much moisture before it stops doing its job. I once worked in a lab where silica gel was used as a drying agent, and we would regularly have to dry it out in a low-temperature oven before it could be re-used. Link to comment Share on other sites More sharing options...
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