Don't kid yourself. Photo Grade is one of many grades; USP
Originally Posted by efreddi
is another. Some other this group likely can name half a
dozen chemistry grades You can bet that there are
at least a few grades of borax.
Likely not so much photo grade chemistry is sold now
as in days gone by. Likely tons/month were being
This is very likely a false assumption.
Originally Posted by gainer
And how many manufacturers - good question. From RIo Tinto's web page, www.borax.com - "Rio Tinto Borax operates California’s largest open pit mine in Boron, California - one of the richest borate deposits on the planet. The company supplies nearly half the world’s demand for refined borates, minerals essential to life and modern living."
Go look at that page. See how many applications they are producing borax for. Do you think they are making these grades just for the heck of it? Do you really think that each and every grade is using borax that has simply been dug out of the ground with no additional refining? They most certainly are not.
Have you been to a borax plant and seen how they mine the stuff? I have - It's next to the town of Boron, CA. It's next to Edwards Air Force Base in the Mojave Desert. The borax at Boron, CA is from an open pit mine. They dissolve the mineral with hot water and then it goes into large, open pools to let the water evaporate and they are subject to any dirt the weather happens to bring along. Check out the satellite shot of it from google http://maps.google.com/maps?f=q&hl=e...&t=h&z=13&om=1 You can see how they are evaporating the ore and then they collect it in heavy machinery. Not a very clean process.
It's just like using the right tool for the right job. Sure a flat bladed screw driver can drive screws, but when you need to drive a Philip head, or a Torx head or any of the other kinds of screws, you really will get the best performance with the right tool. Same thing applies to chemical grades.
I've said it before and I'll say it again: Everyone wants to produce quality photos from economy priced chemicals and films and papers. Everyone wants quality from teaspoon measures and eyedropper measures rather than grams and milliliters.
If you want quality, you pay for it or you get dirt, dust, or that 5% impurity of 'whatever' when you read the label and it says 95% pure.
If you buy economy products of any sort, then why use an expensive timer, just count one one thousand, two one thousand, three onethousand and etc. to time the development, fixing and washing. Guesstimate times for exposure too.
Suppose you are right and the 20 Mule Team Borax is not what they claim, 100% sodium tetraborate decahydrate. When you buy it from Photographers' Formulary do you get any assurance that their's is in fact 100%? Does anyone in APUG have evidence that using 20 Mule Team borax has caused a problem in any of the many recipes that call for borax? Do you know the tolerance for error in any of these recipes? Can you supply evidence, personal or published, that ordinary grocery store borax is not good enough? As for teaspoon measures, have you tested those for consistency of weight or effect on photographic solutions? I have, long ago, and reported my results in an article for Petersen's Photographic (April, 1973) called "Kitchen Tested Soups". Kodak's instructions for those who want to mix their developers from scratch is to have a scale or balance good to 0.1 grams.
Researchers like PE need to know such things as tolerances, deviations from experimentally determined optima that will not cause noticable difference in performance, if their discoveries are to be put to practical use. You know for fact that as soon as one opens a package of dry ingredients to mix a developer, the ingredients are likely to be changed, and who knows what changes will occur when local water is used to mix them. What specifications would Kodak put on an order for borax, or sodium sulfite, or hydroquinone, or Metol for packaging the components of D-76?
I have a cheap timer from Radio Shack and a metronome. The timer does very well, thank you, for measuring time of development to the second if needed, and the metronome is quite good for timing exposures under the enlarger.
I'm with Gainer. There is a lot more room for error, or leeway, or whatever one wishes to call it, when mixing photographic chemistry than some would have us believe. I still have a copy of his article from 1973 and pass it along to current students. Too many times in my life I have headed for the kitchen when missing an ingredient then have everything turn out correctly to worry so much about purity. Sure, there are exceptions, but I believe they are the exception.
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Based on my personal experiences, a small deviation in chemistry measurement generally has little impact on the output of my pictures. The greatest source of deviations for me is temperature control and once I've refined that art, my pictures markedly improved in quality and consistency.
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OK....let's have everybody pitch in $5 and we'll send a box of 20 Mule Team Borax off to a lab for testing & find out precisely what's in there besides the borax
I throw my film into all kinds of homemade concoctions ( Tri-X screams like a lobster in the bubbling brew ), but I wouldn't dare put somebody's wedding photo's in my cauldron
gotta run, need to get more eye-of-newt
Originally Posted by gainer
Patrick's post is so good, it bears repeating.
There does not appear to be any evidence what so ever to support the hypothesis that 20 Mule team Borax from the grocery store is insufficiently pure for use in B&W developers.
Further, regarding "Photo Grade" chemicals...I suggest you find a real definition of what that excatly means. It does not mean "pure" by any stretch of the imagination, in fact, photo grade can have all kinds of impurities - just not significant levels of impurities that would have a detrimental effect in the intended photographic applications.
I have noticed a difference with Borax.
Many years ago I was trying to put together a solution, the only Borax I could get my hands on was some from a hardware store, fine I thought. Well not quite!
I was mixing a film developer, cannot remember what but if say it was D76, I would only have used 2gms for 1 litre.
What I found was that what I dropped in, didn't all go into solution. Eventually I figured it must have been impurities, so I finished the solution, cooled it, then filtered out the solids.
As far as I know the solution developed the film alright, otherwise I would have made a some warning notes for myself.
Currently, I use Analytical reagent grade Sodium Tetraborate, with a purity of 99.101%, for my film developing solutions.
I wouldn't really know how much difference, cost wise, this purity is, as I am on the last of two large bottles I bought in the late sixties.
When borax is specified for use in developers by knowledgable persons it is the decahydrate. Fortunately, in most developers it is used as a buffer, and its buffer pH is phenomenally independent of concentration. Otherwise, in using the analytical reagent grade sodium tetraborate you are not necessarilly doing yourself a favor. The molecular weight of the tetraborate is 201.22 and that of its decahydrate is 381.37. If you weigh 2 grams of the anhydrous tetraborate you are getting the equivalent of 3.8 grams of borax.
Originally Posted by Mick Fagan
I have never in 50 years or so never seen any undissolved sediment in a borax solution that could not be attributed to exceeding the solubility of borax. In other words, if I added more water or increased the temperature, the sediment would dissolve. I have always used 20 Mule Team Borax.
You can if you wish continue to use the analytical grade, but check to make sure it is the decahydrate or reduce the amount accordingly.