Using vacuum sealer for photo chems

juan

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I have one of the machines made for vacuum sealing food in plastic bags before freezing. I was looking at my big containers of sodium thiosulfate, kodalk, and sodium sulfite I use to make TF-2 fixer. I’m thinking of mixing these chemicals in the proper amounts for mixing with 1-liter of water, sealing them and storing them that way. Anyone see a problem with that?
 

bdial

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It seems like an idea with much merit, as long as you can keep the vacuum pump from ingesting any powder. Please let us know how it works out.
 

MattKing

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And I guess it goes without saying - label the filled bags very clearly, and don't let them get anywhere near any bags with food in them.
I think if we had one in our household, my wife would be very uncomfortable if I used it with chemicals. I would need to buy one of my own.
 

grat

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I don't know how effective it is for long term storage, but I did the same thing with some D76 recently, and and didn't have any problems with the powder being sucked into the sealer.

I now have a relatively oxygen free brick of D76.
 

grat

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As an FYI, if you fold the top down so the top of the bag is inverted (ie, like a collar around the opening of the bag), it makes it easier to prevent any chemicals from getting on the outside of the bag. Since the sealer works on vacuum, the chances of any chemicals getting transferred into a bag containing food is roughly zero-- obviously, it's not absolutely zero, but these bags are designed for extreme temperatures, and to be puncture resistant, so some basic precautions should be sufficient.

Note, this is for dry ingredients-- for liquid, that's a whole 'nother story. Liquids can be stored in bags, but there's almost always some seepage while sealing.

I'd like some bottles with caps with one-way vacuum valves in them for storing liquids, but they're difficult to find.
 

MattKing

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In my bachelor days, when I just had myself to reassure, I would probably have considered it!
 

grain elevator

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I don't think the vacuum is that beneficial, but the airtight sealing that these machines do could be great. You could eleminate the risk to the vacuum pump by leaving it off. The small amount of oxygen in the bag probably won't do much harm.
 
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juan

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That’s exactly what I plan. Just press as much air out as I can, then use the sealer function. When I bought Kodak and Ansco fixer in bags, they were not vacuum sealed.
 

MattKing

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juan said:
That’s exactly what I plan. Just press as much air out as I can, then use the sealer function.
Click to expand...
I could probably convince my wife to let me do that !
 

wiltw

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Developer is the main thing that oxidizes...chemical reaction with oxygen, which is why folks used to spray nitrigogen into developer bottles to make it last . So I would not bother with vacuum bagging anything except developer. And just how impemeable are the vacuum bags for food?!
 

MattKing

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The vacuum bags may also be good for keeping out moisture, and if they are fairly strong, may be resistant to physical damage, so they would be worth considering for those reasons.
 

grat

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juan said:
That’s exactly what I plan. Just press as much air out as I can, then use the sealer function.
Click to expand...

Tip: Dunk your bag in a water bath, with the chemicals at the bottom of the bag. As you force the bag under water, the water pressure will force the air out of the bag, and if it's something like a sealable freezer bag, you can seal it with practically no air in the bag by getting the sealing strip as close to the water as possible.

Not as good as a hard vacuum, but doesn't require any special equipment other than a tub of water.
MattKing said:
The vacuum bags may also be good for keeping out moisture, and if they are fairly strong, may be resistant to physical damage, so they would be worth considering for those reasons.
Click to expand...

A good seal in a food storage bag will extend food life by a factor of 4, give or take. 6 months for dry products turns into 2 years, refrigerated foods go from 3 days to two weeks, frozen foods can easily hit 3 years without freezer burn, primarily due to not just the lack of oxygen, but also water vapor.

The two rolls I have right now are 4mm thick BPA free plastic. I also use them for cooking sous vide (which also means I have a pretty accurate water bath when doing developing). They're pretty tough-- you can puncture them if you try, but you're unlikely to accidentally tear them open.

Since they're rolls, I cut a length off the roll, seal it at one end, fill it, seal it at the other end. Another neat trick is to make the bag longer than needed-- then you can cut the existing seal off, remove some quantity, then reseal the bag.
 
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