Thread: Silver Bromide
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Old 04-26-2002, 10:06 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
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Pete VanderLaan is on a distinguished road

if you don't have it, buy it. Page 99 3rd edition. It can also be found in Bob Helds' NCECA manual printed back in the sixties. The manual you won't find, get the book, it has other silver recipies as well.

You need 112 grams silver nitrate and 78 grams of sodium bromide. Mix each one separately in a pint of tepid water. Henry says distilled, I use the tap. Once the crystals have totally dissolved pour one into the other while stirring briskly. Make sure the second container is big enough to take the liquid from both beakers.

This will immediately turn into a yellow green sludge that is no longer photosensitive. The sludge will occupy the entire space you gave it.

This is also an exothermic reaction, generating heat, so make sure the water is tepid, not hot because it will get hotter. You don't want to break your containers.

Pour the sludgew into filter paper in a funnel, I use paper towels. Once the liquid is passed thru, squeeze the paper towels ( use lots so they don't break). Take the silver bromide baseball you have just made out and break it into the desired sized chunks. Dry them out at under 400F. Guess why. ( OK, it will melt).

Now this stuff is insoluble in anything that I have ever tried and you will come up with tons of unusable crumbs. Save them and the next time you make bromide, pour them into the bromide beaker and then into the general mix. They will become trapped in the new batch.
Someday I will figure out how to explain making your own silver nitrate which is easy and dangerous. I have yet to pass an OSHA test for my technique. It does reduce the cost of silver nitrate by about half.
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