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Old 22nd February 2020, 11:37 AM
Quendil Quendil is offline
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Default Silica GelPackets

I'm sure I am not the only one that uses Silica Gel packets to stop moisture when storing cameras and lenses.

My question for people that have used them for a long time, in general how often do you change them?

I know this will depend on the moisture contents of where the items are stored but was wondering whether I should change mine ever year or more frequently? My camera gear is stored in plastic containers in my roof space which is boarded and insulated to make a hobby room.


Thanks
David
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Old 22nd February 2020, 12:39 PM
Terry S Terry S is offline
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Quote:
Originally Posted by Quendil View Post
I'm sure I am not the only one that uses Silica Gel packets to stop moisture when storing cameras and lenses.

My question for people that have used them for a long time, in general how often do you change them?

I know this will depend on the moisture contents of where the items are stored but was wondering whether I should change mine ever year or more frequently? My camera gear is stored in plastic containers in my roof space which is boarded and insulated to make a hobby room.


Thanks
David
Having it all in plastic containers will really help David, with the silica gel helping as well.

I've not used it for a long time, but I believe that you can put it in a warmish over to re-dry it, to then be able to use it again.

Well worth a google.

Terry S
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Old 22nd February 2020, 01:14 PM
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I don't use it for my cameras but I do use it for other purposes and what I do is buy it in reusable packets. Then, as Terry says, placing in a warm oven (120 degrees C - don't go too high as it can damage them) for 1 or 2 hours, or for 2 x 5 mins on the lowest power setting in a microwave (but make sure there are enough holes in in the packaging for the steam to escape without rupturing the package or a mess will ensue). I prefer the oven as it is gentler on the gel/crystals.

What I do is weight them on my chemical scales. Initially, weight them after you have dried them in the oven for a few hours to ensure they are completely dry to get their dry weight. Then leave them in a dampish place for a week (easy enough in the UK at this time of year if you have a shed etc - but don't run them under the tap!) so they become completely charged with moisture. Weight them and make a note; this is their wet weight.

Dry them again until they reach close to their measured dry-weight (there are diminishing returns on time in the oven versus amount of moisture removed, so in practice you should not need 2 or 3 hours to recharge them to 90% of fully dry each time - I only do that the first time to ensure they are as dry as reasonably possible when I measure their dry-weight).

Dry them out in the oven again and put them with the cameras/lenses.

Now weight them from time to time and when they weigh half the difference between their wet and dry weights, recharge them again back to dry.


A bit oif a faff, but good for your peace of mind that the gel is working.


Also worth pointing out that there is no point putting gel with the cameras and lenses if they are not in sealed containers - the gel will be powerless against the onslaught of constantly circulating damp air.

Last edited by Bob; 22nd February 2020 at 06:35 PM.
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Old 22nd February 2020, 06:06 PM
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Dave Hodson Dave Hodson is offline
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I buy the re-useable indicating silica gel beads that change colour with moisture off Amazon (mine go from orange to dark green).

It's a bit finnicky(don't drop them cause they go everywhere) but I buy the 2 lb container and make little baggies out of those cheap nylon socks your grandma used to wear. You can buy a box of them for a few bucks in the dollar store. Gentle reheating in the oven restores them (take them out of their baggies).
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Old 22nd February 2020, 07:48 PM
Mike O'Pray Mike O'Pray is online now
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So putting a couple of silica gel packets in a camera lens holder or camera bag that is made of permeable material such as canvas or even leather with zip fasteners would be of negligible or as good as negligible help?

Secondly I take it that if cameras are kept in say drawers in a house the normal relative humidity say 60-65% ( according to my RH dial on my barometer in the hallway) is low enough to be considered safe?

Thanks

Mike
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Old 22nd February 2020, 10:01 PM
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Originally Posted by Mike O'Pray View Post
So putting a couple of silica gel packets in a camera lens holder or camera bag that is made of permeable material such as canvas or even leather with zip fasteners would be of negligible or as good as negligible help?

Thanks

Mike
Canvas (unless waterproofed) would not be ideal I'd have thought. There will be a constant flow of air in and out of the bag, bringing damper air with it. However, the low turnover of air in a zipped-up bag might well be enough to maintain a drier than ambient level. It all depends if the desiccant can absorb the moisture faster than air currents can replace it.

Sounds like another job for experiment: weigh some dry desiccant, put half in open air and half in a closed camera bag and see if they gain weight at the same rate, or not.


A quick google suggest that 30-50% RH is ideal - but that is for normal fungal growth (bathroom grout, mildew etc) - presumably also applies to the type that grows on lenses, but IDK.
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Old 23rd February 2020, 12:35 AM
Mike O'Pray Mike O'Pray is online now
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A quick google suggest that 30-50% RH is ideal - but that is for normal fungal growth (bathroom grout, mildew etc) - presumably also applies to the type that grows on lenses, but IDK.
Thanks Bob. The problem is that my RH dial may be wrong and it certainly isn't an instrument whose accuracy would be acceptable to the meteorological office but unless a house has a means of reducing its RH to a much lower level then I imagine is possible without "artificial" means such as large dehumidifiers then 60% may be the best that is available.

I have no reason to believe that my house is anymore humid than most but as I say my RH dial may be way off. It's cheap barometer/ RH dial and quite old now

To-date I haven't noticed a problem with any of my lenses and the humidity of the air( I presume this is outside ) would appear to be much higher than 50-55% in the U.K. based on a Google search

Mike
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Old 23rd February 2020, 10:41 AM
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I'd think that if you are not seeing any problems then don't worry about it. From the brief searching last night it seems is is the combination of temperatures over 21C and RH of 70 or above that is the time to worry (but as said, that is for the normal kinds of growth you might get in a bathroom or on damp wood which is all the technical details I found with a quick look, but I imagine fungus is fungus, so probably still applies).

Fresh packets of desiccant can't do any harm, but I would weight them to see if they are (a) still working or, (b) full of water so have stopped working. Though, if you don't have small chemical scales that may prove difficult as kitchen scales will not be accurate enough unless you use a hundred grams of the stuff...
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Old 23rd February 2020, 12:55 PM
Mike O'Pray Mike O'Pray is online now
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Thanks Bob. I have a digital scale that is accurate to 1 gram so I might give weighing pre and post drying a go out of curiosity

Mike
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Old 23rd February 2020, 06:24 PM
Quendil Quendil is offline
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Thanks for all the responses. I do google etc searches for most thing but I trust the answers I get on here more then anywhere else.
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