Recharging Desiccant

I'm just hours away from my next trip... departing to Cozumel, Mexico for a stay of a little over two months! Camera is ready, dive gear (including a whole lotta cave gear) is packed, everything looks good to go. BUT. While packing my desiccant I noticed I hadn't dried it in a while. Probably not since last year's Cozumel trip. Here's some notes on when you should dry your desiccant and how to do it.

I use SeaLife "Moisture Munchers" which come 10 to a pack for about $8. SeaLife part number SL911. The main reason I use these is because they are rechargeable, and have a built-in dye indicator to show their condition. They are bright blue when fully dry, and eventually fade to a dull pink when they are used up. Typically if they are starting to look between purple and pink is when I stop using a Moisture Muncher capsule.

The picture above shows three capsules successfully recharged, and three that blew up probably because their holes were too small to let the rapidly expanding moisture escape. Note the deep rich cobalt blue colour. This is your goal!

To recharge, follow these directions:

• Set oven temperature to 275 F (135 C)
  
• Place used capsules between two pieces of corrugated cardboard, and put the carboard on a baking sheet
  
• Place baking sheet in the middle rack of the oven
  
• Bake for 20-40 minutes, checking every 10 minutes or so for that cobalt blue colour which indicates they are finished
  
• Bake additional 10-15 minutes, to be sure the desiccant in the middle of each capsule is done
  

Important!

• Do not use a toaster oven. They are very bad at regulating temperature and you will either melt the capsules or cause the cardboard to catch on fire!
  
• Do not leave in oven longer than 1 hour
  
• You may need to poke larger holes in some of the capsules especially if they are wet
  
• The reason you use cardboard is to protect capsules from radiative heat and to avoid contact with the metal baking pan. You only want convective heat to remove the moisture. Radiative heat will melt and deform the capsules!
  

In some cases, if the capsules are saturated or you use too high a heat, they will blow up like balloons. If this happens you can still use the capsule (as long as the desiccant isn't leaking out of them) but they may not fit inside your underwater housing anymore. I just throw 'em out if they get deformed. They're pretty cheap and I buy several packets at a time.

Remember! Desiccant is a drying agent, not a sponge. It will absorb small quantities of moisture in ambient air trapped in your housing. It will NOT protect your camera if visible moisture gets in there (such as flooding).

I don't know if there is a limit to how many times you can recharge your desiccant capsules. Probably as long as they recharge to a blue colour they are still usable. I have recharged mine at least 5 cycles now.