+alligatorsnz Posted January 12, 2012 Share Posted January 12, 2012 where do i get a desiccant like silca gel in auckland new zealand? Quote Link to comment
+The A-Team Posted January 12, 2012 Share Posted January 12, 2012 where do i get a desiccant like silca gel in auckland new zealand? I can't answer your question, but I will say that if you're planning on putting little silica packets in your caches, don't bother. They only absorb a tiny amount of moisture and will VERY quickly become ineffective. You'd be better to put that money toward a decent waterproof container. Quote Link to comment
+kunarion Posted January 12, 2012 Share Posted January 12, 2012 where do i get a desiccant like silca gel in auckland new zealand? Some "crystal" cat litter is silica gel. You can also buy it in craft stores to dehydrate flowers. Quote Link to comment
+NanCycle Posted January 12, 2012 Share Posted January 12, 2012 Quote from Gitchee-Gummee in another thread: Silica gel packets are only as good as you maintain them. The little packet you speak of came in a SEALED container -- not opened until the consumer end. It is a temporary measure (at best). Given more adverse conditions, what will happen is the silica collects moisture, only to release it as the humidity/dampness drops. So... it keeps the water vapor at a level -- high! Large canisters of silica are used in gun safes, but it periodically must be "recharged" by oven baking, to remove the moisture. Short run - it helps; Long run - it hurts. I doubt that a little packet in such conditions is going to make a hill of beans difference. Quote Link to comment
+W4G_SOTAGoat Posted January 13, 2012 Share Posted January 13, 2012 I made some gel "packs" with burlap. Put it in a waterproof case just as good measure. You can buy the stuff at a crafts store and then use pretty much anything to make a pack. Panty hose, a sock, etc. Quote Link to comment
+kunarion Posted January 13, 2012 Share Posted January 13, 2012 I made some gel "packs" with burlap. Put it in a waterproof case just as good measure. You can buy the stuff at a crafts store and then use pretty much anything to make a pack. Panty hose, a sock, etc. I put two sock-fuls in a flooded cache. My plan was to dry the soaked log book, and that worked really well (silica gel may be the only way to dry a log book inside a wet container, if the log's in an isolated ziplock). A stop-gap measure to at least dry the log until the Cache Owner could take care of it. But a cacher came along and dropped one of the socks into the water in the bucket. That idea didn't work so well. More like sock stew. Quote Link to comment
+Stargazer22 Posted January 13, 2012 Share Posted January 13, 2012 One factor that limits the usefulness of silica gel that is commonly overlooked is it's capacity to absorb water at higher temperatures. At temperatures of 77 degrees F and below, it has good adsorbtion properties. Above 77 degrees F it's capacity to absorb water drops rapidly and eventually it will reach a temperature where it releases more water than it absorbs. This is why silica gel can commonly be "recharged" by putting it into a 200 degree oven for a period of time. The acutal amount of water that can be absorbed by silica gel is pretty good for sealed containers, but remember that caches aren't going to stay sealed up. They will be periodically opened up which lets more moisture back in again. Typically at about 40% relative humidity, 100 grams of silica gel will absorb about 35 grams of water. Given the densities of the 2 substances, that means that to absorb about 5 ounces of water you would need just over a cup of silica gel. After several openings of the cache, you would then need to remove the gel and recharge it to get any more drying effect. Silica gel is best used for sealed containers in moderate temperature environments that will seldomly be opened. Quote Link to comment
+kunarion Posted January 13, 2012 Share Posted January 13, 2012 (edited) After several openings of the cache, you would then need to remove the gel and recharge it to get any more drying effect. Yes. The CO would need to swap it out regularly. A CO that attentive won't have water in the container anyway. Maybe the OP is planning an unusual container that isn't watertight or gets water inside, and a frequent replacement of silica gel is just the ticket. Maybe the OP intends to rescue a soaked log by segregating it with dessicant in a ziplock til the CO can fix the leak. Either way is probably worth a shot. I haven't tested temperature ranges, but a sock-ful of silica gel four times the volume of the log book, will completely dry out a soaked log book, even in the heat of Georgia summer, in a couple of days. I don't always have extra days to spare hanging out at someone's cache waiting for the log to dry out, so if it's ever gonna dry, it will have to be with dessicant in a new sealed ziplock. People always drop by these posts to suggest that COs who ignore their caches will have problems using silica gel since it won't hold water forever. Which is an obnoxious suggestion, since non-maintenance is bad regardless of whether there's silica gel or not, AND some of us maintain our caches. A bunch of dessicant will dry the contents so everything's not ruined, until the CO can arrive to fix it. If the CO never does arrive, maybe it extends the life of the cache for a little while. It can't be any worse than air-drying a log and putting it back into the wet container, and it may actually be better. Edited January 13, 2012 by kunarion Quote Link to comment
+Gitchee-Gummee Posted January 13, 2012 Share Posted January 13, 2012 Newton's 51st law regarding water absorption: 1) Silica gel 2) Paper (of most any kind) 3) Air 4) Cotton fiber 5) Leather 6) [i forget...] (FWIW, I really don't think that Sir Isaac ever knew of silica gel., or it's eventual invention/discovery.) So, you see, it is a battle. The three most water absorbing materials are so closely aligned they will simply trade the water back and forth. The air (or rain itself) brings it (water) into the cache, the silica will absorb it to a point. Paper, being the next best absorbing material happily takes over the job. Cotton and leather resist, but only to a point. This post is all tongue-in-cheek... but, most all of us know that a DRY cache can still hold a soggy log, soggy to the point of unusable. Paper itself, is one of the BEST water absorbing materials. Perhaps we could all switch to cotton or leather log sheets. Rite in the Rain paper (whatever it is called) would be a better choice yet. Maintenance is the big issue, not putting something in the cache as a temporary fix. Temporary fixes (like replacing junk cache containers) make for lazy(er) Cache Owners. The last sentence may sound harsh, but let's face it... the truth hurts, sometimes. I think using (copious amounts) of silica to dry a wet log is a good idea, but that is what it would be good for, little else. The stuff is like a sponge and it will soon make the cache into something that a person was trying to prevent. To put it into a cache, and the CO remain unresponsive is going to be... well, disastrous. The little packets that come with a camera, electronic items, etc., are next to worthless in a real-world environment. They would soon be more "junk" that needs to be cleaned out of a cache. None of this is to make an argument, it's just trying create an understanding of the basic problem. Maintenance. Quote Link to comment
+Sol seaker Posted January 17, 2012 Share Posted January 17, 2012 DON'T!! When silica gel gets wet enough it turns to mush and makes a mess. You've got to continually do maintenance on it. Rather than going through the trouble and the money of that, just buy waterproof paper and a good waterproof container. Groundspeak sells both. I live in the Pacific Northwest and it is indeed wet up here. We get rain 11 months out of the year, and sometimes in the 12th. Good waterproof containers are indispensible. No one up here uses dessicants. They just use good waterproof containers such as ammo cans, bison tubes,or lock and locks (use the brand name ones, sometimes Target has them, Groundspeak sells them already labeled with waterproof logs inside). NO film cans or pill bottles. These just don't work. Thanks for caring enough to put out a good cache. Quote Link to comment
+akkatracker Posted January 20, 2012 Share Posted January 20, 2012 where do i get a desiccant like silca gel in auckland new zealand? As no-one is answering your questions I will. In Australia I bought a box of shoes from the Puma outlet, while I was at it I took as many silca packs as possiblee Quote Link to comment
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