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Borax purity grade

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Yes, I'm still reading, and learning. Although I haven't enjoyed the arguing, I have very much enjoyed the insights into various standards, grading, etc. and possible repercussions, or lack thereof. I'm not mixing my own chems, except occasionally from a kit.

It is, for instance, reassuring to know that 20 mule team is a possible substitute if photo grade becomes unavailable, should I start to mix my own, if should I want to experiment with something I couldn't get off the shelf, or in the future couldn't get anything the shelf at all.
 
re: solids

I don't have a ball mill, but I do have coffee filters...would that get rid of the solid matter, or is it too fine for a coffee filter to remove?
 
DarkroomExperimente said:
re: solids

I don't have a ball mill, but I do have coffee filters...would that get rid of the solid matter, or is it too fine for a coffee filter to remove?
Click to expand...

AFAIK, that would not work. The particle size has to be either above or below a certain limit and I forget the numeric values. Above, it can't diffuse into swollen gelatin and below, you can't see it at a reasonable magnification in a print.

Generally, if you mix the solution and see an opalescence under diffuse light after filtration, the size is 'bad'. This is a rough guesstimate.

PE
 
JBrunner said:
Yes, I'm still reading, and learning. Although I haven't enjoyed the arguing, I have very much enjoyed the insights into various standards, grading, etc. and possible repercussions, or lack thereof. I'm not mixing my own chems, except occasionally from a kit.

It is, for instance, reassuring to know that 20 mule team is a possible substitute if photo grade becomes unavailable, should I start to mix my own, if should I want to experiment with something I couldn't get off the shelf, or in the future couldn't get anything the shelf at all.
Click to expand...

JB;

I agree. I have not enjoyed the arguing and have apologized to all. I'm sorry but I have wanted to prevent accidents or ruined pictures.

Yes, 20 Mule Team Borax can be used, but I cannot say what the consequences in quality will be. And, it might vary from batch to batch. That is the crux of the matter.

I hope Sheriff Mark Chase is reading this from his Death Valley retreat.

PE
 
Photo Engineer said:
I was considering the question again sitting here and have come up with a set of problems to illustrate this for you.

A photo grade chemical might be designated with a solids content of 1%, but the ANSI Photo Grade standard also defines the size of this particulate matter. And so, two chemicals with the same 1% impurity as solids but with two different sizes in that particulate matter might represent a pass and a fail of the ANSI standards.

The ACS grade often denotes halide presence as "total halide content", but for Photo Grade, the ANSI standards that we worked with gave each halide a percentage value. This therefore could classify the possible uses of chemicals for emulsion making only or for film emulsion only and etc. You see, Iodide content is critical in Sodium Chloride for a Chloro/Bromide, but much less so for a Bromo/Iodide.

Below a certain level, the halides present become rather unimportant for processing chemcials but above a certain level again the type of halide is critical for processing solutions.

Calcium and Potassium levels are of critical importance in fixes, and so a fixer must be free of those salts or it can be poisoned as a fixer. (See Mees and James or Haist on this one) They are not very important at all in developers except that a sloppy processor could carry too much developer with a Potassium salt into his fixer.

I hope this further clarifies this matter (if anyone is even reading this anymore).

PE
Click to expand...

The method of manufacture does minimize solids, but that is the least of the problems if you use the method of preparing a saturated stock solution. In that case, anything but soluble material should be at the bottom of the container. The real concern should be the soluble iron, chlorine, etc., and the spec sheet I saw showed those to be at levels below the analytical grade. That spec sheet is outdated, and may no longer apply since borax has changed corporate hands a couple of times since. It seems, though, that you are stuck on insoluble matter that might wind up in the emulsion of any user of 20 Mule Team Borax, even though you do not know that it is any worse in that regard than what you are using. I maintain that the use of a saturated solution and the temperature tables is the most accurate way to go for both borax content and insoluble solid content. It is certainly the simplest. I think the concern over supersaturation should be investigated, but otherwise it seems to be the best we ordinary people can do.
 
DarkroomExperimente said:
If you get that opalescence does that mean that the particle size is somewhere near the wavelength of visible light?
Click to expand...

To answer you and Patrick.

For you, I would have to say IDK for sure about size vs wavelength. After all, color and refractive index of the solid and solution are involved.

For Patrick and you there is another answer involved as well.

If there are particles which have settled out, then they are really large and therefore fall above the limit, but if they are opalescent they could be at or below the 'bad' level.

Patrick's assumption that bad stuff settles out is incorrect. Brownian motion and Van der Waals forces can keep small but harmful particles in suspension and keep them from settling. Hydrogen bonding with the Borate ion can also be in force here AFAIK. Surface tension on the particle is also involved.

This is sometimes counter intuitive, but it is a common misconception that all particles must settle out or be filtered out. So, his statement "In that case, anything but soluble material should be at the bottom of the container" is totally incorrect!

There are stainless steel filters available that filter at the micron level, but the cost is astronomical. I think buying better chemicals is the answer or the use of recrystallization and filtration. A good fluted paper filter can often do wonders.

I hate to keep arguing this over and over. Sorry, but to me, I'm pointing out obvious errors that the other party is sure is correct.

PE
 
I should add further that to prove that this statement by Patrick is incorrect "In that case, anything but soluble material should be at the bottom of the container", the suspension of small particles in solution, and the observation of their motion was what led to the discovery of Brownian Motion.

PE
 
Photo Engineer said:
I should add further that to prove that this statement by Patrick is incorrect "In that case, anything but soluble material should be at the bottom of the container", the suspension of small particles in solution, and the observation of their motion was what led to the discovery of Brownian Motion.

PE
Click to expand...

Big Al got himself a Nobel for that one.
 
well, I have noticed that dust floats in air...a kid I knew in 1st grade said he used to think sunlight was "dirty light" because you saw so much stuff floating around in it
 
I had been watching too many Jay Leno monologues (before the writers strike) which referred to Al's Nobel prize in terms of how big (read fat in less polite speak) he had gotten. Hahaha. Ok, thanks. I had forgotten Albert Einstein's contribution as I thought of Robert Brown primarily.

Thanks for jogging a flagging memory.

PE
 
I have watched this thread with interest. The problem with using non specified chemicals is not so much that you can or cannot use them. The real problem starts when you have a problem occcuring at some point and you have no idea what caused it. It could be an adverse reaction between two trace chemicals in two other chemicals. You have no idea. Where do you start trouble shooting? Never mind what film or other product was ruined. I have been fortunate so far in that any solutions I have mixed have worked. I would never use a product not certified to perform as expected.

A related situation occured a few years ago just after 5 p.m. on a Friday. Film put through one of my processors had black dots all over it. It took a while to figure out that a piece of film folded by accident and flicked a few drops of fixer into the developer. Not good to be trouble shooting a problem and hoping that you can meet deadlines without reverting to hand processing a couple of hundred large prints. Or mixing 5 gallons of fixer then finding the next morning that your stainless custom made tank has a 1/2" crust of rust just above the liquid level.
 
Well, I was hoping they were clones or the same person, thereby not making me in error.

However, considering this thread, I thought you might mean Weird Al.

Dead Link Removed

PE
 
"Richard;

I agree with your observations. You have explained how too many variables can obfuscate the problem.

I have a few more specific examples.

Lets assume a 5% impurity in commercial Borax.

If it is Sodium Sulfate, there will be virtually no effect on pH or on sensitometry if you use standard levels of buffer and dilution, but if you use the developer for long times or dilute it substantially, there is the potential that contrast and speed will go down. You see, since Sodium Sulfate is neutral to this situation, the developer is 5% low in buffer capacity and this will only show up in keeping, heavy use or high dilution. D76 diluted would be a case in point.

If it is Magnesium Sulfate, it will form a solid precipitate which is about 5% by weight. If you filter out the solid you are pretty much back to the above scenario, but if you add enough sequestrant (TSP for example) you will form Magnesium Phosphate which will raise the pH by as much as 0.1 - 0.5 pH units and change the buffer capacity downwards. Phosphate alone is a poorer buffer than Borate at pH values where Borate is used. This can cause an initial increase in contrast which would then drop with dilution, use or keeping.

If you varied between a 5% contaminant of one or the other or just inert silicates, you would have a situtation where you were varying in pH to a small extent and in contrast and speed which might be on the order of 1/3 stop or about 0.05 - 0.1 contrast units. This contrast variation would be on the order of 1/2 grade in the paper you might use.

BTW, this also applies to 'pool grade' Sodium Carbonate which was discussed in the thread Kirk referred to above. The pH and buffer capacity would vary by as much as 5% depending on the nature of the impurity.

I've already explained what would happen if this 5% impurity was a halide, but lets assume that the impurity consists of mixtures of all of the possible (so called benign) items discussed so far. Then the diagnostic process and the results become rather hopeless as Richard described above. It also decreases your process uniformity if you strive for quality results.

The presence of minute silicate particles might not even be noticed if small enough. If large enough, you might mistake them for grain or you might not see them until you reached higher magnification.

This has been a discussion on what you can observe and test for. I have left out the potential effects on sharpness which would be about 5% as well, but much harder to test for the average person.

PE
 
take what PE said and multiply it by 100,000 and you have my darkroom

did I use the wrong type of coffee? maybe I didn't remove enough dirt from the mint I yanked out of the ground etc etc
 
gainer said:
The method of manufacture does minimize solids, but that is the least of the problems if you use the method of preparing a saturated stock solution. In that case, anything but soluble material should be at the bottom of the container.
Click to expand...

Patrick, go get some muddy water out of the creek running down the side the your street when it rains and collect a liter of it. THen pour it into a 1 L graduated cylinder or, even better, a glass device called an "Imhoff Cone". Let the water sit for an hour and you'll see how much suspended material remains in the liquid above the larger bits of dirt that settle to the bottom. There will be lots of insoluble matter still floating in the water. Wait a week, and you will still see stuff suspended, and some of it will never settle and the water will still look turbid from it.
 
Kirk Keyes said:
Patrick, go get some muddy water out of the creek running down the side the your street when it rains and collect a liter of it. THen pour it into a 1 L graduated cylinder or, even better, a glass device called an "Imhoff Cone". Let the water sit for an hour and you'll see how much suspended material remains in the liquid above the larger bits of dirt that settle to the bottom. There will be lots of insoluble matter still floating in the water. Wait a week, and you will still see stuff suspended, and some of it will never settle and the water will still look turbid from it.
Click to expand...

That would be a new experience for me. I live in West Virginia. Our runs have potable water. Some of our wells have really thick green stuff coming out, but we can sell that to ignorant out-of-staters for big bucks.:D

I just made a saturated solution of MC and let it sit for an hour or so. No sign of anything in the clear part. Usually even a colloidal suspension will show, but none here.
 
I have to make one last comment before I throw up my hands in frustration. I have shown product specs that guarantee certain impurities will be =< some level in MC and that they are comparable to a specially processed borax from Rose Mill, and to the analytical grade, and I am waiting in vain for the corresponding specs for whatever PE uses. For my part, I could develop film for the rest of my life without using borax. I have certainly gone all my life thus far without intentionally or accidentally ingesting a teaspoon of borax. I do not even remember how all this got started. I'm beginning to feel a bit of a persecution complex. I guess I'll have to talk to my nephew the clinical psychologist about that.

You'll have to excuse me for not knowing the connection between Boron and rocket fuel. We had nothing to do with that at Langley Research Center.
 
I'm still reading and enjoying the technical side which is rather over my head, but worth it.

Mick.
 
gainer said:
You keep dancing around the original argument which dealt with the suitability of 20 Mule Team Borax for photographic purposes. I have quoted the guaranteed specs of that stuff, which specify that the impurities are guaranteed to be much less than those listed on the container of analytical grade borax that Mick Fagan got.
Click to expand...

PAt, you are completely wrong here. Your 20 Mule Team has no specification for insoluble matter. Therefore it cannot exceed the specifications that Mick's AR grade meets. And I would bet that Photograde has a specification for insoluble matter as well, and so it would not exceed that specification either.

If you're comparing specifications, you have to look at ALL of the specifications.

If you cannot see the logic of that, I pity you.
 
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