DIYMark Posted June 16, 2008 Posted June 16, 2008 Ive been desperately in need for a Desiccator to store my KNSU fuel for rockets! Ive read that CuCl2 is good, but I cant get it here unless I make it, but then the HCl I'd be using is of "unknown" concentration (the bottle says 30% - accuracy to that is unknown). So Ive lent to another compound that Ive read works well - CuSO4. For the price of getting the copper and HCl to make CuCl2, I can buy 500grams of CuSO4. So I'm wondering if anyone can shed some light on using copper sulfate for Desiccators. I'm thinking It'll be better because I can see when is is absorbing moisture (turns blue!) Anyone has any ideas? or Alternatives for Desiccator compounds? (NaOH?)
justanotherpyro Posted June 16, 2008 Posted June 16, 2008 NaCl and KCl. You can also get Silica gell from shoe boxes etc...I used to work at a store that would have various products shipped with large packets of the stuff and I would collect them. If you know someone that might work in a store that has them in its packages try and have them collect it. CuSO4 would work better if you dried it in an oven( just make sure not to melt it) but NaCl and KCl are both cheap, easily available and will work as a decent dessicant.
oskarchem Posted June 16, 2008 Posted June 16, 2008 Or, if you can get cheap 96-98% H2SO4 you can use that... But I don't know how KNSU would react to this...
crazyboy25 Posted June 16, 2008 Posted June 16, 2008 Anhydrous magnesium sulfate. Heat epsom salts in the oven at 400 degrees for 2-3 hours.
mike_au Posted June 16, 2008 Posted June 16, 2008 Check out bunnings, they have calcium chloride in the "storage" area. They have special boxes of the stuff for about $20-30 and refills for about $5, just get a refill and tip some in a plastic cup. They also had coloured silica gel pack with a built in heating element for $50. Which would be nice if you could get it without the $40 worth of heater.
DIYMark Posted June 16, 2008 Author Posted June 16, 2008 Thanks guys for the quick replies! I will first lookout in Bunnings then if nothing shows, I'll use Magnesium Sulfate (So it has an other use then sitting on the supermarket shelf!)
Yankie Posted June 16, 2008 Posted June 16, 2008 Regular table salt works for me. I have a kilo of magnesium nitrate with no use for it, does anyone know if this is useful for anything?
Boomer Posted June 16, 2008 Posted June 16, 2008 How are KCl or NaCl going to work as a desiccant? Mg nitrate might work, and the perchlorate too. The CaCl2 in shops is already partly hydrated. Baking it improves it a lot. Or why not simply seal them up? Put grains in mason jar, tighten lid - done. You might even purge with a dry gas, anything from N2O via CO2 to butane will work. Or add a little silica baggy. This is just to get the little water out that the air inside the jar holds. If not opened repeatedly it should not be needed.
Swede Posted June 16, 2008 Posted June 16, 2008 Anhydrous magnesium sulfate. Heat epsom salts in the oven at 400 degrees for 2-3 hours. I believe this ^^ or calcium chloride ("Damp Rid" in the U.S.) would work best. In either case, baking the salts as mentioned at 300 to 400 degrees for a few hours will drive off any starting moisture. Place a layer of the salts on the bottom of your container, and add a screen; something to keep your product off of the salts. The salts gather water and eventually clump, but they will keep your rocket engines bone dry.
tentacles Posted June 16, 2008 Posted June 16, 2008 Around here CaCl2 is used for melting ice from driveways, super cheap that way... Just dry it in the oven before using as a dessicant.
DIYMark Posted June 17, 2008 Author Posted June 17, 2008 I think Ill just use the Epsom salts (Magnesium sulfate) because It'll only cost like 2 bucks for 500grams at the shop!
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