Dessicant (Reactivation)

[donperry]

I have 3 bags of dessicants that came in some computer device packaging. They are about 5x5 inches and has the following on it:

 

ACTIVATED BENTONITE

Static dehumidification Specification

MIL-D 3464E

Reactivation time in bag 16 hours at 245F

 

 

Can this be used for keeping water away from my KN/SU propellants?

[Bilbobaker]

I have 3 bags of dessicants that came in some computer device packaging. They are about 5x5 inches and has the following on it:

 

ACTIVATED BENTONITE

Static dehumidification Specification

MIL-D 3464E

Reactivation time in bag 16 hours at 245F

 

 

Can this be used for keeping water away from my KN/SU propellants?

 

I would think a bit of time in a food dryer or oven would re activate it for use as a desiccant.

Pharmacy's are great places to get lots of free bags of it.

They get loads of it in their supply boxes daily.

[Bilbobaker]

Do you keep your rcandy in tubes ready to launch or just singe well wrapped grains?

I'm pretty new at storing them so any info at all is helpful.

It's my favorite rocket fuel but I've still some timing issues for the recovery chute burst timing.

It's been to wet to do more testing so I've been fishing for lake trout and bass on the weekends instead of rocket launch tests.

[dagabu]

Do you keep your rcandy in tubes ready to launch or just singe well wrapped grains?

I'm pretty new at storing them so any info at all is helpful.

It's my favorite rocket fuel but I've still some timing issues for the recovery chute burst timing.

It's been to wet to do more testing so I've been fishing for lake trout and bass on the weekends instead of rocket launch tests.

 

I store R-candy in grains inside a sealed pail with desiccant. Damp rid works well for me as it is more hygroscopic then R-candy.

 

-dag

[donperry]

So dag, the idea is to have something that is more hygroscopic than what we storing?

So would placing some sugar in a paper bag work?

[dagabu]

So dag, the idea is to have something that is more hygroscopic than what we storing?

So would placing some sugar in a paper bag work?

 

I'm sorry but no, raw sugar in no more hygroscopic them the fuel grains made from table sugar. Bentonite that is baked for a while like stated above works well if it is poured into the bottom of the pail and the grains are stored on top of it (paper towel or barrier between the grains and desiccant). Make sure it is cool and that the storage area does not get above 75°F. Sugar starts to melt and get tacky without any water as it heats up and water exacerbates the effect.

 

-dag

[shagaKahn]

Can't say specifically for Rcandy but for BP, silica gel works great. Keep packets of it in all my BP jars--and it can easily be reactivated in a warm oven.

 

As someone else posted, ask folks who get a lot of shipping; no reason actually to have to buy the stuff.

[toster]

Plus with Silica gel you can make water glass, or magic rocks

[dagabu]

. Keep packets of it in all my BP jars--and it can easily be reactivated in a warm oven.

 

I dont bother to dry my BP or use desiccant in it. I just put it into a bucket and seal it.

 

-dag

[oldguy]

If you want very inexpensive desiccant.

Heat some rock salt up in an oven around 225 F for 20 or 30 minutes.

Once cooled, put it in a dry paper bag.

Put the bag in your container with whatever else & you are good to go.

Desiccant doesn't get much cheaper than that.

Edited May 18, 2011 by oldguy

[NightHawkInLight]

Calcium chloride works great, and costs about $5/50lbs last I checked. Sucks water out of the air FAST.

[dagabu]

Calcium chloride works great, and costs about $5/50lbs last I checked. Sucks water out of the air FAST.

 

Thats what Damp-Rid is made from, just watch out!!! It absorbs the water and then becomes a liquid.

 

-dag

[NightHawkInLight]

Thats what Damp-Rid is made from, just watch out!!! It absorbs the water and then becomes a liquid.

 

-dag

 

I use it to cover the bottom of a 5 gallon bucket. I then place whatever needs drying in a bowl on the bottom of said bucket. If what needs drying is long, like a rocket or multibreak shell, I just place the bottom in the bowl and lean it against the wall. Drys my pasting in a matter of hours and keeps the 100% Michigan humidity away.

[dagabu]

I use it to cover the bottom of a 5 gallon bucket. I then place whatever needs drying in a bowl on the bottom of said bucket. If what needs drying is long, like a rocket or multibreak shell, I just place the bottom in the bowl and lean it against the wall. Drys my pasting in a matter of hours and keeps the 100% Michigan humidity away.

 

Sweet! I have had a shell that got wet in a bucket of Calcium chloride so I bought a damp-rid bucket more for the strainer and lid then anything else and use Calcium chloride out of the bag to recharge it. Lots of ways to skin a cat...

 

-dag

[MadMax]

You can also use rice or kitty litter. They can both be reused too by heating in an oven. Personally I don't bother trying to keep everything dry. The rockets/shells/devices I make I always waterproof them. Once finished they get dipped in regular old wood finish, dried and then dipped again. I find ways to ensure they are all completely waterproof to the point where they can be submerged and then used immediately if need be. I do this right down to the fuse. I paint right over the end of it where the BP is exposed and then dip that end in NC-bound BP to keep it easy to light. I'm actually working on making waterproof BP at the moment too - one of many projects.

 

I started doing this because I noticed the sweat from my hands would dampen completed things and I was getting paranoid that the moisture would be able to sink right down to the comp/stars/inserts within and make them less reactive.

 

As far as the raw r-candy I store it in preformed cylinders or large hunks and keep them in mason jars as I do with BP as well.

 

Note: Storing anything combustible in glass does carry with it a certain risk of projectile shards if it ignites in confinement. Do at one's own risk.

[shagaKahn]

Love your suggestion to use heat-dried rock salt, OldGuy. Lo-tech--read FREE-tech--is my favorite way to go.

 

Only reason I use silica gel is I got several hundred packets of it in all sizes from some packaging I was recycling.

 

They sell these dry-kits here--think they're called Dri-z-air and I believe it's Calcium Chloride. Can that compound be "re-activated" by heating or is it shot once it's wet? 'Cause that seems to be the absolute mutha of all desiccants.

[NightHawkInLight]

Love your suggestion to use heat-dried rock salt, OldGuy. Lo-tech--read FREE-tech--is my favorite way to go.

 

Only reason I use silica gel is I got several hundred packets of it in all sizes from some packaging I was recycling.

 

They sell these dry-kits here--think they're called Dri-z-air and I believe it's Calcium Chloride. Can that compound be "re-activated" by heating or is it shot once it's wet? 'Cause that seems to be the absolute mutha of all desiccants.

 

You can dry out any desiccant. Calcium chloride is almost certainly available in 50 lb bags at every hardware store outside of 3rd world countries. A common name for it is painters desiccant.

[Mumbles]

Something to keep in mind is desiccant strength. For it to "steal" away water, the desiccant must have a higher water affinity than the material that is wet. I don't know for sure that rock salt, rice, or clay would be stronger than r-candy or something like that. They'll probably work fine for keeping them dry, but I wouldn't count on them to dry already wet material. Additionally, those two don't have a great deal of water capacity compared to something like CaCl2.

 

Calcium chloride is probably around the same price as rock salt, as they're used for the same thing. If you use the CaCl2 designed for melting ice, sometimes it has a protective coating on it, which will probably require cracking to be effective as a desiccant. It relies on snow or water dissolving off the outer layer to get at the good stuff. The stuff designed as a dessicant, or to keep dust down on roads or baseball parks, it will likely not have the coating.

 

I personally like heat and air flow to dry my items. A drying box will dry 6 layers of fully broken in 70lb kraft in an afternoon. This includes the crown and bottom of the shell too, which are well over 6 actual layers.

[Mumbles]

You can dry out any desiccant. Calcium chloride is almost certainly available in 50 lb bags at every hardware store outside of 3rd world countries. A common name for it is painters desiccant.

 

That's not exactly true. All of the desiccants mentioned in this thread can be dried out with heat. If you'd like to prove me wrong, please feel free to show me you drying some calcium or magnesium nitrate, Iron Chloride or phosphorous pentoxide.

 

BTW, another cheap and effective desiccant you guys may want to look into is Magnesium Sulfate (epsom salts). There is also sodium sulfate, but it's not as active as calcium chloride or magnesium sulfate, though it ultimately holds more water. Both of these will stay solid at room temp.

[oldguy]

This puppy will dry out about anything that will fit in the trays.

Once dry, seal it in something air/water tight & its generally good for years.

Food saver type vaccum sealers work wonders.

[FrankRizzo]

Oldguy,

 

How do find that dehydrator working with the epic stack of trays you've got? I've go the same setup, but find that over 10 trays, the drying capacity suffers pretty bad.

[oldguy]

I have several. I just stacked the trays for the picture.

However, capacity is not affected (much), if you turn another base unit upside down & run 1 on the bottom & 1 on the top (up side down).

[Peret]

Personally I use Drierite, which is calcium sulfate (gypsum) based. It's thirstier than silica gel and doesn't deliquesce like calcium chloride. The indicating kind rather usefully changes color when it needs to be regenerated.