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aaronnate
10-Jan-2019, 14:00
I know this is probably real easy and I'm probably over thinking but it has been about 25 years since I mixed up a developer from scratch. I only did it once, it was in a college chemistry lab, under a hood, weighing with a triple beam balance, using a magnetic stirrer.

I've ordered the chemicals for Pyrocat-HD but realized I have no lab ware. Can someone recommend the dishes and lab supplies I will need?

Is a regular digital food scale (dedicated to this obviously) acceptable?

jp
10-Jan-2019, 14:06
You can get little drug dealing scales on ebay/amazon that measure the small amount of grams for most of this stuff quite inexpensively.

The powdered pyrocatechin is bad stuff to have loose in powder form, so dispense and dissolve that outside.

aaronnate
10-Jan-2019, 14:40
You can get little drug dealing scales on ebay/amazon that measure the small amount of grams for most of this stuff quite inexpensively.

The powdered pyrocatechin is bad stuff to have loose in powder form, so dispense and dissolve that outside.

Are those scales called pocket scales?

Bob Salomon
10-Jan-2019, 14:44
Are those scales called pocket scales?

Oahus

jp
10-Jan-2019, 14:47
Are those scales called pocket scales?

Yes

Steven Ruttenberg
10-Jan-2019, 14:48
I prefer tripple beam balance, no batteries, easily calibrated, works for forever and as accurate if not more so than any digital scale in the same class of weights being measured.

Pere Casals
10-Jan-2019, 16:03
Is a regular digital food scale (dedicated to this obviously) acceptable?

Yes, but even the best Lab scale requires Calibration Weights, some $6, Amazon, to know if it works ok.

186283

You also would need an additional precision jewelry type Scale, with 0.01gr or better 0.001gr precision, say a $10 one, some include and small calibration weights set, if not you will also need one. That scale would be of 100 to 500 max load.

186284


You may need that small scale for some ingredients, for example to mix 1 Liter of Mytol, (Xtol substitute) you need to measure 0.15gr of phenidone, you would not be able to do it with a food scale.

Best way is having two scales, a food type one for say 40gr and up, and a jewelry one for under that. And, I reiterate, it's important having calibration weights.

koraks
10-Jan-2019, 16:28
You can make a 5% phenidone stock solution in 96% ethanol. Easier to weigh and measure and lasts quite long.

Pere Casals
10-Jan-2019, 16:39
Yes, but then you need 50grs of phenidone, worth to make 333L of Mytol (50/0.15), adding cost of Ethanol this is 3x the cost of the jewelry scale, with a single ingredient.

Belive me, the small scale is a must... any ingredient under 10gr may have a 10% error with a food scale, or 20% if it has 2gr steps, ...and having to dilute many ingredients, this is a mess...

I use mine for DIY emulsions, to me it would not be practical the food scale, which I use when weight is larger.

Two23
10-Jan-2019, 16:51
I'm on my state's grand jury. I'll mention that if you keep one of these scales in your car and it has white powder residue on it, any cop stopping you for a traffic violation is going to go nuts when he sees that scale.


Kent in SD

Pere Casals
10-Jan-2019, 16:55
I'm on my state's grand jury. I'll mention that if you keep one of these scales in your car and it has white powder residue on it, any cop stopping you for a traffic violation is going to go nuts when he sees that scale.
Kent in SD

:) you can give the cop a dose of phenidone, to make him happy :) :)

Steven Ruttenberg
10-Jan-2019, 16:59
I am by trained a certified calibration expert. A 6 dollar mass set from Amazon or other place will not be very calibrated. Tripple beam can go down to like .1 grams and lower depending the model you get.

Bob Salomon
10-Jan-2019, 17:15
I'm on my state's grand jury. I'll mention that if you keep one of these scales in your car and it has white powder residue on it, any cop stopping you for a traffic violation is going to go nuts when he sees that scale.


Kent in SD

In the 70s I sold Ohaus scales, among other photo items, to a small camera store along the Delaware river in PA. This store, in a small town, not near a city, was buying several scales each month. After a few months, on one stop there, I asked the owner where he sold all of these scales? He explained that there was a group of “farmers” that were growing a type of hemp and were constantly being busted by the cops and their equipment was confiscated and they had to replace it all, among the necessities of their business was the Ohaus scales!

Pere Casals
10-Jan-2019, 17:22
I am by trade a certified calibration expert. A 6 dollar mass set from Amazon or other place will not be very calibrated. Tripple beam can go down to like .1 grams and lower depending the model you get.

Steven, Instant Mytol has to be mixed before usage, you may want 300ml stock for a 600ml 1:1 of it to make 12 4x5 sheets, then you may need to measure 0.045grs of phenidone (0.15*300/1000) for that. If your scale makes 0.1grs...

This $11 one is class M2, norm , OIML R 111-1 : https://www.amazon.com/American-Weigh-Scales-Calibration-WGHTKIT/dp/B003STEJAC/ref=sr_1_1?ie=UTF8&qid=1547165718&sr=8-1&keywords=weight+calibration+set+m2

A M2 calibration is aproved to sell gold...

jp
10-Jan-2019, 18:35
Nothing official about it, but remember that 1cc or ml of water is 1 gram. If you want to verify how your jewelry/pocket scales work, you can put 10ml of water in a small medicine measure which you'd zero'd the scale with dry, and it should be 10g. Or zero it with an empty 2-3ml plastic pipette and draw up some water to the line, and measure it's mass again for smaller amounts.

Pere Casals
10-Jan-2019, 18:58
Nothing official about it, but remember that 1cc or ml of water is 1 gram. If you want to verify how your jewelry/pocket scales work, you can put 10ml of water in a small medicine measure which you'd zero'd the scale with dry, and it should be 10g. Or zero it with an empty 2-3ml plastic pipette and draw up some water to the line, and measure it's mass again for smaller amounts.

Yes, you are right, by weighting water volumes we can see if scales are good enough, this solves most of the problem.

Anyway checking a jewelry scale is more difficult. Imagine next case: a jewelry scale performs acceptably at say 10grs, but it has some dirt inside provocating an slight vertical friction, and it has a hysteresis of 30mg, the phenidone for 300ml (12 4x5 sheets) of the instant mytol is 45mg...

This $11 kit allows to check if the scale also works well with low (say 45mg) loads, as it even includes a 10mg weight.

186292

Well, $11 to be sure that one nails the chemical formulas... the kit will last for ever...

In darkroom practice the water method would be suitable for the food scale, the jewelry scale IMHO needs more the calbration weights, the one I have came with the weights, if you browse amazon you will find than many come with weights, but many don't include small weights...

When I prepare an emulsion I always check the scale first, for the moment I'm making small batches to test, and there are several reagents that are used in small quantities and requiring precision, iodine for example, and of course the sensitizing dyes. It's for this that I use the jewelry scale, because I'm not mixing developers at the moment.

Steven Ruttenberg
10-Jan-2019, 22:46
Even water has a standard and depending on where it is from, it can be off. For example if you use a water softener, the density will be less than one.

They have triple beam and other mechanical a scales that go to.01 and smaller. The issue with any scale that could measure down to.045 gms would need to be shielded all around or the mass will be off due to just breathing and minor air currents. Even temperature fluctions. Then add in the error of scale, say +/- 10% and now you could have anywhere between.0495gms -.0405gms while scale in theory reads exactly 0.045gms. If you're saying you need precisely 0.045gms or formula won't work, your toast.

My point is this is not an exact science so how precise/accurate do you really need to be so long as proportions are maintained. Also, one can, with experience, read down to half of what scale resolution is, but not on a digital scale.

Anyway, whatever works best for someone is the best scale to use.

And having been a Deputy, scales, little baggies, white residue, brow residue and yellow residue pretty much got you a ride to hotel from hell. Or if you fought a little, you got stomped on and then a free ride. :)

koraks
11-Jan-2019, 04:25
Belive me, the small scale is a must...
I never said otherwise. Still, for stuff like phenidone of which you need fractions of a gram, stock solutions are more convenient and arguably more consistent than weighing the dry powder for every batch of developer you make. Since I generally mix several small batches of various developers a week, I suppose I would know.
This approach also works very well for mixing small volumes of pyrocat stock, which would be of interest to Steven in particular.

Pere Casals
11-Jan-2019, 05:11
If you're saying you need precisely 0.045gms or formula won't work, your toast.

Steven, if mytol formula says 0.045gms for 300ml, perhaps it will work nearly the same with 0.040 or 0.060gr, being a +50% quantity the second case, the but anyway you require an scale with at least 0.01gr for that, and if possible a 0.001gr one. I presented the phenidone case to point that even in that extreme situation you can avoid making dilutions.

As koraks mentioned, dilution solves the phenidone issue, if this was the single problem...

but anyway if a pocket sized scale solves all dosification for ingredients in the grams range...

My view is that a food scale is first what we need, but if we often manage quantities under (say) 15gr then the cheap jewelry scale is a must.

Me at lest, I'm really happy to use one, I found it extremly useful and convenient for the DIY emulsions, in that case consistency has many factors, and the last you want is having any uncertainty in the small quantities you mix, when I started with DIY emulsions it was a nightmare, bottles of dilutions everywere, and always calculating the watter addition, all to not have accurate doses because sometines not having enough reagent quantity to make a dilution volume. $10 investment and all problems evaporated.

Steven Ruttenberg
11-Jan-2019, 08:41
As long as you are consistent and use same scale for all your weighing, then the errors will all be the same and you will get consistency. I was just pointing out, that to be accurate and precise if that is your goal, that a tripple beam will do that and that for the really small stuff it will need to be shielded. If you want digital, here ya go, but ain't cheap.

https://www.hogentogler.com/veritas/m124a-analytical-balance.asp?gclid=EAIaIQobChMIuJ2cqIjm3wIVdx-tBh0H7AJREAQYBCABEgInAvD_BwE

Peter Lewin
11-Jan-2019, 09:19
This thread, and Steve's other thread on mixing your own Pyrocat-HD, have me thinking. I still have my triple-beam Ohaus from when I first read AA's books and mixed my own D-23, but that is a bunch of decades ago. I used to take a lightweight plastic container from the kitchen, weigh it empty, and then add the desired chemical powders to that tare weight (I think that's the term). That seemed pretty simple, but wondered how those of you currently using scales to mix developers and fixers do it, i.e. I can't imagine you pour the powder to be weighed directly on the scale platform?.

jp
11-Jan-2019, 09:33
Balances have adjustments on them for the same purpose. Just not as simple as pressing a button and seeing the zeros line up. Some of them it's a screw or slider to adjust it back into balance with the container on it.

I certainly agree $11 is a bargain for a set of calibration masses. But we're not weighing milligrams of mytol in this thread, it's for measuring grams for pyrocat hd.

koraks
11-Jan-2019, 09:38
This thread, and Steve's other thread on mixing your own Pyrocat-HD, have me thinking. I still have my triple-beam Ohaus from when I first read AA's books and mixed my own D-23, but that is a bunch of decades ago. I used to take a lightweight plastic container from the kitchen, weigh it empty, and then add the desired chemical powders to that tare weight (I think that's the term). That seemed pretty simple, but wondered how those of you currently using scales to mix developers and fixers do it, i.e. I can't imagine you pour the powder to be weighed directly on the scale platform?.
I use an appropriate container (which can be as simple as a piece of folded tinfoil) and place it on the measurement platform of a cheap digital scale (precision 0.01g). I then zero it out and proceed to weigh out the chemicals. I dunno, sounds pretty simple because it is.

Don't place chemicals directly onto your scale (whether analog or digital) because you WILL induce corrosion.

Pere Casals
11-Jan-2019, 09:55
As long as you are consistent and use same scale for all your weighing, then the errors will all be the same and you will get consistency

The M2 calibration weights I pointed is what ensures me total consistency, even an expensive scale may go wrong. An scale is as good as the calibration weight with we check it. By routine, before using it I check it with the 10mg and 10g calibrated weights, reading always nails the weight, except some two times that some dirt was between the platform and the base.


i.e. I can't imagine you pour the powder to be weighed directly on the scale platform?.

Never !!! one should not generate dust from chem !!!

Usually a plastic container is used on the scale, then we tare, and then a plastic spoon of the right size may be used to crefully leave the powder on it, sometimes with the help of an small stick to add some crystals if necesary.

Pere Casals
11-Jan-2019, 10:04
it's for measuring grams for pyrocat hd.

Ok, but for 1L of Py-hd, Part A, you need to measure:

Phenidone 2.0 g
Potassium Bromide 1.0 g

If we want to measure 1.0g accurately we need the 0.01gr scale. Using a 0.1gr scale may easily end in a 20% error.

Bernice Loui
11-Jan-2019, 10:12
Mixing Foto chemistry from powder was the way to reduce chemistry cost, assure fresh chemistry, potency of chemistry. Dry powder chemicals last a lot longer than mixed in a bottle. Items that are basic requirements:

*Copy of the Photo Lab Index, https://archive.org/details/aa143-PhotoLabIndexCompactEdition/page/n11

*Copy of the book Developing by Jacobson, https://archive.org/details/DevelopingTheNegativeTechnique/page/n3

*Optional Photo chemistry books like Book of Pyro by Gordon Hutchings (PMK).

*Dry chemicals as specified in these books.

*Clean filtered or distilled water to mix the required chemistry.

*Industry standard Chemistry lab glass wear, Graduated cylinders from 25mL to 1000mL, Pyrex beakers from 100mL to 1000mL, Erlenmeyer flask from 250mL to 1000mL, Glass bottles with good caps for mixed chemistry storage (Erlenmeyer flask can be used and works good for mixed chemistry storage).

*Dry chemistry scoops. Disposable plastic spoons work OK for this.

*Accurate thermometer like a Kodak Lab process thermometer or similar lab grade-certified accuracy thermometer.

*Accurate gram-grain scale with a tare (zero with measuring container) feature.

*Magnetic stirring unit and magnetic teflon stirring bars of various sizes, https://www.amazon.com/Magnetic-stirrer-magnetic-Stirring-Capacity/dp/B072K24X5P/ref=asc_df_B072K24X5P/?tag=hyprod-20&linkCode=df0&hvadid=198074333025&hvpos=1o2&hvnetw=g&hvrand=18348286875595210888&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031909&hvtargid=pla-355194351026&psc=1


These are very basic Chemistry tools and the same tools needed to mix photo chemistry. It is very possible once any photographer goes down this road to mixing your own, purchasing chemistry in a bottle might not happen often any more. There are formulations that cannot be purchased with special features not available in pre-mixed chemistry from a bottle. After much trial and experimentation it is very possible there will be settling into a few basic photo chemistry formulations that work well for the goals and image making objectives needed in much the same way as choice of film, optics, camera and all related to the expressive image making process.


Bernice

Randy Moe
11-Jan-2019, 10:37
I worked in a testing chem lab for Crane Packing Co in 1972.

Used 3 Analytical Balances daily.

I have everything Bernice recommends.

I bought this very delicate scale 4 years ago (https://www.amazon.com/American-Weigh-AWS-100-Digital-Resolution/dp/B0012LOQUQ#customerReviews) and

Plastic Hexagonal Weigh Boats. (https://www.amazon.com/Heathrow-Scientific-Polystyrene-Hexagonal-Antistatic/dp/B0062VPMW2/ref=sr_1_10?s=electronics&ie=UTF8&qid=1547228102&sr=8-10&keywords=Plastic+Hexagonal+Weigh+Boats)

Sfroza
11-Jan-2019, 10:49
I use these, $4.00 per 100. Cheap and disposable.

Eagle Thermoplastics D43-100 aluminum dishes: crinkle w/tabs 1.0g, 43 mm i.d. (pn: d43-100) 100 per pack

Michael

Steven Ruttenberg
11-Jan-2019, 10:58
Ok, but for 1L of Py-hd, Part A, you need to measure:

Phenidone 2.0 g
Potassium Bromide 1.0 g

If we want to measure 1.0g accurately we need the 0.01gr scale. Using a 0.1gr scale may easily end in a 20% error.

As long as your scale is accurate (and you are accurate, also different than smallest size you can measure) ie, how close am I to a known value and you have precision, ie repeatability, then the error of the scale is all you need to worry about. So typically, if you measure in increments of 1gm, and the error on that is .1, that is no good, regardless of how accurate or precise you. But if the error is =/- .01 gms then you are good (again, this has nothing to do with the resolution of the scale, ie how small an increment you can measure to.

What if the error on measurement of a scale with .01gms is .1 gms? Then no matter how accurate and precise you are, your measured quantity is worthless. Possible if cheaply made. So for a scale that has .01gm increments the error would need to be kept to at least +/-.001gms.

As for the "calibrated" masses, they need to have been measured by something traceable to the National Bureau of Standards for the country one leaves in or chooses that is 4 times more accurate than the masses being calibrated. In turn then the masses need to be at least 4 times more accurate than the scale you are using for the user calibration to be considered truly accurate. That is, if I use a calibrated weight that is 4 times more accurate than my scale is when set to the same mass, and I can repeat that measurement several times with that mass and other masses of the same size all calibrated to 4 times my scales accuracy, then not only is my scale accurate, but it is precise and that is what we are looking for along with an error at least 1/100 of the smallest mass you can measure to.

So, if you are need things in the 1gm increment range, a scale with an error of +/-0.01gms that has been calibrated and shown to be both accurate and precise will do just fine. Then reason you need smaller increments, like .1, .01, etc is because your sample size is smaller and the best you can do is to interpolate to half the given smallest increment. But if the tolerance on the scale is not small enough, then you cannot interpolate.

Just because a scale has say .001gm increments does not mean that measuring 0.05gms is what you get. That scale could be bat crazy inaccurate, but precise and even inaccurate and imprecise, both scenarios will give you crap results, even if your tolerance for the scale was +/-0.00001gms. However, a scale that measures in 0.01gm increments that is accurate and precise with an tolerance of +/-0.001gms will far out perform the so-called better scale. Plus the .01 increment scale vs the .001 increment scale will be much cheaper.

Steven Ruttenberg
11-Jan-2019, 11:01
I worked in a testing chem lab for Crane Packing Co in 1972.

Used 3 Analytical Balances daily.

I have everything Bernice recommends.

I bought this very delicate scale 4 years ago (https://www.amazon.com/American-Weigh-AWS-100-Digital-Resolution/dp/B0012LOQUQ#customerReviews) and

Plastic Hexagonal Weigh Boats. (https://www.amazon.com/Heathrow-Scientific-Polystyrene-Hexagonal-Antistatic/dp/B0062VPMW2/ref=sr_1_10?s=electronics&ie=UTF8&qid=1547228102&sr=8-10&keywords=Plastic+Hexagonal+Weigh+Boats)

I like the little boats

Steven Ruttenberg
11-Jan-2019, 11:02
Mixing Foto chemistry from powder was the way to reduce chemistry cost, assure fresh chemistry, potency of chemistry. Dry powder chemicals last a lot longer than mixed in a bottle. Items that are basic requirements:

*Copy of the Photo Lab Index, https://archive.org/details/aa143-PhotoLabIndexCompactEdition/page/n11

*Copy of the book Developing by Jacobson, https://archive.org/details/DevelopingTheNegativeTechnique/page/n3

*Optional Photo chemistry books like Book of Pyro by Gordon Hutchings (PMK).

*Dry chemicals as specified in these books.

*Clean filtered or distilled water to mix the required chemistry.

*Industry standard Chemistry lab glass wear, Graduated cylinders from 25mL to 1000mL, Pyrex beakers from 100mL to 1000mL, Erlenmeyer flask from 250mL to 1000mL, Glass bottles with good caps for mixed chemistry storage (Erlenmeyer flask can be used and works good for mixed chemistry storage).

*Dry chemistry scoops. Disposable plastic spoons work OK for this.

*Accurate thermometer like a Kodak Lab process thermometer or similar lab grade-certified accuracy thermometer.

*Accurate gram-grain scale with a tare (zero with measuring container) feature.

*Magnetic stirring unit and magnetic teflon stirring bars of various sizes, https://www.amazon.com/Magnetic-stirrer-magnetic-Stirring-Capacity/dp/B072K24X5P/ref=asc_df_B072K24X5P/?tag=hyprod-20&linkCode=df0&hvadid=198074333025&hvpos=1o2&hvnetw=g&hvrand=18348286875595210888&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031909&hvtargid=pla-355194351026&psc=1


These are very basic Chemistry tools and the same tools needed to mix photo chemistry. It is very possible once any photographer goes down this road to mixing your own, purchasing chemistry in a bottle might not happen often any more. There are formulations that cannot be purchased with special features not available in pre-mixed chemistry from a bottle. After much trial and experimentation it is very possible there will be settling into a few basic photo chemistry formulations that work well for the goals and image making objectives needed in much the same way as choice of film, optics, camera and all related to the expressive image making process.


Bernice

Have most of that stuff. Gonna get a couple additional and duplicate items, then I am good to go.

Pere Casals
11-Jan-2019, 11:18
*Copy of the Photo Lab Index, https://archive.org/details/aa143-PhotoLabIndexCompactEdition/page/n11

*Copy of the book Developing by Jacobson, https://archive.org/details/DevelopingTheNegativeTechnique/page/n3

https://www.amazon.com/Magnetic-stirrer-magnetic-Stirring-Capacity/dp/B072K24X5P/ref=asc_df_B072K24X5P/?tag=hyprod-20&linkCode=df0&hvadid=198074333025&hvpos=1o2&hvnetw=g&hvrand=18348286875595210888&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031909&hvtargid=pla-355194351026&psc=1
Bernice

Nice links... Thanks for posting that.

Only to add that for the magnetic stirrer, it may be worth to get one with heating, probe and thermostat. Today this can be cheap, some $50, IIRC. This allows to prepare photographic emulsions.

Bernice Loui
11-Jan-2019, 11:35
:)

Magnetic stirrer with teflon stirring bar is standard issue in all modern Chemistry facilities. "Don't Mix Chemistry Without it"..

The resulting mixing uniformity and ease of use is well worth the entry cost.



Bernice



Nice links... Thanks for posting that.

Only to add that for the magnetic stirrer, it may be worth to get one with heating, probe and thermostat. Today this can be cheap, some $50, IIRC. This allows to prepare photographic emulsions.

Randy Moe
11-Jan-2019, 11:39
And it can run unattended under a vent hood

I have dead chem lab coworkers that ignored safety

Peter Lewin
11-Jan-2019, 13:25
JP, Koraks, Thanks! I always used the adjustment on the Ohaus balance just to zero it, missed the obvious purpose to zero out the tare weight. In hindsight, painfully obvious.

Wayne
11-Jan-2019, 13:38
It sounds like I'm using a slightly less precise method than some of you.

186303

LabRat
11-Jan-2019, 18:24
I think of mixing one's own chemistry to be a lot like cooking... With several ingredents, one can make may different dishes, but buying pre mix is like buying frozen food... Just one thing, and expensive...

A mag mixer is something I won't live without, as it mixes while you focus on measuring the ingredents, and almost always, you can mix most chems at room temp, as it does such a good job, only sometimes with old chem rocks, or phenidone, so heat usually not needed... If you use a lot of old rocky chems, a mortar helps to smash and grind...

Note the upper weight limit of the scale you choose, as some formulas require very little of a dev agent, or restrainer, but maybe a lot of sodium sulfite, hypo etc...

All dry chems should be filtered before use, as there is sometimes some dirty specks in them, and if you reuse any chem it should be filtered... I use a large funnel, and if you fold a large coffee filter just right, it will filter well in a reasonable amount of time... I use Melita #6 white from the supermarket and filter directly into storage bottles...

For storage bottles, I just use 1 and 2 ltr soda bottles... They seal well, strong, and heat and cool well... Store 'em where it's dark, and chem lasts very long (at least 6 months for standard stock solutions when filled to the top...


Another good source for developer and other formulas is a copy of a British Journal of Photography yearbook, at your local used bookstore for a few bucks...

Once you do it, you won't want to go back!!! (And it develops the latent mad scientist in you!!!) ;-)

Have fun!!!

Steve K

Bernice Loui
11-Jan-2019, 19:28
Some time in the mid-1990's a Foto friend got me to try mixing photo chemistry from powder. This was not too difficult as there is some Chemistry in my past.

Once mixing up photo chemistry took hold there was no real turning back due to the possibilities, cost and many other good things. This was helped by a purchase of a HUGE batch of dry chemistry from a fellow who closed up his once large darkroom. Adding to this, the local photo store had most any dry photo chemistry on the shelf.

IMO, to do serious darkroom work, mixing photo chemistry from powder is required. This along with a proper darkroom with a GOOD enlarger is mandatory.

This is one of the possible reasons why most have stopped wet darkroom printing, there is a enormous investment and resourced required to do this properly. This also adds another layer-aspect of control to the expressive image making process.

Yes, it is much like cooking. But, be very aware some of this stuff is LETHAL. Proper caution and safe chemistry practice must apply. Much like cooking, with proper knowledge and precautions really great things can and will happen.



Bernice




I think of mixing one's own chemistry to be a lot like cooking... With several ingredents, one can make may different dishes, but buying pre mix is like buying frozen food... Just one thing, and expensive...

Once you do it, you won't want to go back!!! (And it develops the latent mad scientist in you!!!) ;-)

Have fun!!!

Steve K

jp
11-Jan-2019, 19:54
Just like in a kitchen I also find infrared thermometers to be useful. Is the heated water warm enough to dissolve a chemical? stir it and read it with the kitchen instrument cat laser toy. Very quick and nothing to clean.

LabRat
11-Jan-2019, 20:22
Just like in a kitchen I also find infrared thermometers to be useful. Is the heated water warm enough to dissolve a chemical? stir it and read it with the kitchen instrument cat laser toy. Very quick and nothing to clean.

Useful tip, but I'm sold on even cheap digital ones, as when you are warming or cooling, you have the decimal temp that will start showing you the trend happening... And if a liquid vessel has a temp inversion layer, you can spot it... (inverting a chem bottle several times usually averages out the temp well before pouring)

Steve K

HMG
12-Jan-2019, 16:25
In the 70s I sold Ohaus scales, among other photo items, to a small camera store along the Delaware river in PA. This store, in a small town, not near a city, was buying several scales each month. After a few months, on one stop there, I asked the owner where he sold all of these scales? He explained that there was a group of “farmers” that were growing a type of hemp and were constantly being busted by the cops and their equipment was confiscated and they had to replace it all, among the necessities of their business was the Ohaus scales!

Which is why you see them offered at police auctions on occasion.

Duolab123
12-Jan-2019, 18:02
I am putting in a word for SI Units :o A gram is g not gm.
Grain is archaic, but if you must there's 24 grains (gr) in a penny weight (dwt) 20 penny weight in a troy ounce (oz t) and 12 ounces in a pound, troy. Which in the good old days 240 English sterling silver pence weighted a troy pound (thus the £ was a troy pound of sterling silver. 0.925 pure silver.) There's been a bit of quantitative easing, especially since WWI.

Of course before SI units everyone had their own definition, barley vs. wheat grains. Whose (foot?) was the longest etc.

I can't remember which, US, NASA, JPL, Mars probe hit Mars at warp speed, instead of slowing down. It was traced back to US engineers, failing to convert back to metric, after some brainstorming in English units.

Of course don't mix up troy vs avoirdupoise as avoirdupoise ounce is 192/175 larger ;)

aaronnate
15-Jan-2019, 09:25
Thanks Bernice. I appreciate the input.

Steven Ruttenberg
15-Jan-2019, 22:57
Have to be careful as g is also used to denote acceleration due to gravity. In the engineering world and physics world we use gms or gm for grand and g for acceleration due to gravity.


I am putting in a word for SI Units :o A gram is g not gm.
Grain is archaic, but if you must there's 24 grains (gr) in a penny weight (dwt) 20 penny weight in a troy ounce (oz t) and 12 ounces in a pound, troy. Which in the good old days 240 English sterling silver pence weighted a troy pound (thus the £ was a troy pound of sterling silver. 0.925 pure silver.) There's been a bit of quantitative easing, especially since WWI.

Of course before SI units everyone had their own definition, barley vs. wheat grains. Whose (foot?) was the longest etc.

I can't remember which, US, NASA, JPL, Mars probe hit Mars at warp speed, instead of slowing down. It was traced back to US engineers, failing to convert back to metric, after some brainstorming in English units.

Of course don't mix up troy vs avoirdupoise as avoirdupoise ounce is 192/175 larger ;)

mrred
15-Jan-2019, 23:27
Yes, but then you need 50grs of phenidone, worth to make 333L of Mytol (50/0.15), adding cost of Ethanol this is 3x the cost of the jewelry scale, with a single ingredient.

Belive me, the small scale is a must... any ingredient under 10gr may have a 10% error with a food scale, or 20% if it has 2gr steps, ...and having to dilute many ingredients, this is a mess...

I use mine for DIY emulsions, to me it would not be practical the food scale, which I use when weight is larger.

I agree with the scale. But your phenidone won't last very long if it's not in solution. It's then mesured with a syringe......accuretly. What the heck are you mixing to need 50g?

koraks
16-Jan-2019, 02:54
But your phenidone won't last very long if it's not in solution.
Really? I've had phenidone sitting around for a few years that didn't seem to be affected by aging. Whereas in a watery solution, it does oxidize. Even in a 96% alcohol solution it turns yellow, suggesting a small part oxidizes. See also here: https://www.photrio.com/forum/threads/shelf-life-of-phenidone.33580/ It is suggested to make a phenidone stock solution in glycol, which I haven't tried, but surely will next time I will have to make a stock.

LabRat
16-Jan-2019, 03:05
Really? I've had phenidone sitting around for a few years that didn't seem to be affected by aging. Whereas in a watery solution, it does oxidize. Even in a 96% alcohol solution it turns yellow, suggesting a small part oxidizes. See also here: https://www.photrio.com/forum/threads/shelf-life-of-phenidone.33580/ It is suggested to make a phenidone stock solution in glycol, which I haven't tried, but surely will next time I will have to make a stock.

I have some really old dry stuff in glass bottles (over 15 yrs old) ,and it still works like new, so I never thought it had a lifespan, unless dry it was severely discolored, but this is the first I heard of it...

YMMV

Steve K

Pere Casals
16-Jan-2019, 03:07
you mixing to need 50g?

Peter, I guess they mixed mix 50g to have accuracy, this would may end easy in practical +/-4% error with a food scale, if mixing 10gr only with a food scale we may have a 10% or even 20% error in the dose. Nothing wrong to dilute 50gr of Phenidone, beyond it's a large ammount, this is a way if one only has a food scale.

...but a jewelry scale would have good accuracy even if mixing 0.05gr. A jewelry scale has x1000 the accuracy of a food scale, so IMHO it's worth to use it when weight is under (say) 50g because by then we may have errors reaching 5% in practice if using a food scale.

Sure, a $10 jewelry scale with a $11 M2 class calibration weights it's what ensures total accuracy if we mix chem. At $11 the calibration weights are a must, for example because any scale may take some dirt that would end in a vertical friction, it's good to check what an scale is doing.

Measure chem twice, shot the scene once ( just a new variation of the proverb :)).

Steven Ruttenberg
16-Jan-2019, 10:19
Don't forget about precision. You can be accurate, but no repeatability which is just as bad.

Jim Galli
16-Jan-2019, 12:59
This (https://www.ebay.com/itm/OHAUS-CENT-O-GRAM-311G-CAPACITY-BALANCE-SCALE-4-BEAM-VERY-GOOD-SHAPE-POWDER/401685832554?hash=item5d8657636a:g:Q18AAOSw1hJcEbLC:rk:2:pf:0) ohaus 311 is what I've used for about the last hundred years or so. Simple and cheap. And it will still work fine after the electromagnetic pulse bomb hits. I use the heck out of the tenths of grams, something the electronic cheapies seem not to do. Yes, PcatHD. But years ago it was good enough to mix my own E6 from scratch. I've redone most of my formulas to come out to be 750ml. Hint; I'm italian and wine bottles make good storage. 5 pages! Everybody makes this harder than it needs to be. I have a plastic 1 liter graduate and a spoon. Somehow I've made a glut of pictures over the years.

Wayne
16-Jan-2019, 16:33
2 pages. I don't know why anyone would use 10 posts per page setting unless they like turning pages :)

Jim Galli
16-Jan-2019, 16:40
Doh, now you made me go to page 6!

Pere Casals
16-Jan-2019, 16:53
But years ago it was good enough to mix my own E6 from scratch.

Jim, it would be very interesnting to me to know about the E6 mix from scratch. Were you using the Watkins ? How did it worked ? Were the slides stable overtime?

Steven Ruttenberg
16-Jan-2019, 17:04
Jim, it would be very interesnting to me to know about the E6 mix from scratch. Were you using the Watkins ? How did it worked ? Were the slides stable overtime?

I would be interested in this as well. Even C-41 would be better.

Pere Casals
16-Jan-2019, 17:19
I would be interested in this as well. Even C-41 would be better.

https://www.photrio.com/forum/threads/mixing-your-own-e6-c41-chemistry.42870/ , se Mowrey's post for E-6 and C-41 mix.

Another one: http://www.opie.net/orphy/photo/dr/wkft-e6.html

You can also buy the color developer (Fuji Hunt) in 20L and mixing the rest, at least this is what I was thinking. CD-3 ingredient may not be easy to find (to me at least), there was some in the auction, but not recently...

Jim Galli
16-Jan-2019, 17:20
Jim, it would be very interesnting to me to know about the E6 mix from scratch. Were you using the Watkins ? How did it worked ? Were the slides stable overtime?


I would be interested in this as well. Even C-41 would be better.

All vanished from my memory now. Some formula in Photo Techniques magazine in the 1980's that we tweaked and fiddled with. I don't want to derail the other guys discussion. It was all pre-computer, late '80's early 1990's. I had some successes, but lots of fails. It was all 35mm Velvia. The color developer was CD3 which was already obsolete even then. Proprietary Kodak. Unobtainium now I would think. I had a decent PH meter and that's all dead now. Once the computers came along, it's sort of a fools errand now I suppose. We wanted the Velvia red's dripping off the page, and that's what computers seem to do best. I never did C41 at all. Not even with a kit. No interest in orange negatives, then or now. Sorry I'm not much help.

Pere Casals
16-Jan-2019, 17:46
All vanished from my memory now. Some formula in Photo Techniques magazine in the 1980's that we tweaked and fiddled with. I don't want to derail the other guys discussion. It was all pre-computer, late '80's early 1990's. I had some successes, but lots of fails. It was all 35mm Velvia. The color developer was CD3 which was already obsolete even then. Proprietary Kodak. Unobtainium now I would think. I had a decent PH meter and that's all dead now. Once the computers came along, it's sort of a fools errand now I suppose. We wanted the Velvia red's dripping off the page, and that's what computers seem to do best. I never did C41 at all. Not even with a kit. No interest in orange negatives, then or now. Sorry I'm not much help.

Thanks Jim, on the way I visited again your photographs...

aaronnate
16-Jan-2019, 19:56
I got what I needed Jim. Derail away.

koraks
17-Jan-2019, 05:40
The color developer was CD3 which was already obsolete even then. Proprietary Kodak. Unobtainium now I would think.
CD3 is still used in RA4 and E6 chemistry. For a private individual it's a little challenging to be purchased, but with a little bit of effort it can be done. I bought a kilogram of it some weeks ago.

neil poulsen
17-Jan-2019, 05:55
If you're mixing powders, I recommend a full face mask to protect the respiratory system. I bought 3M mask years ago from a local safety supply store. It's easy to update the filters.

I sure didn't want D76 or Dektal powder getting into my lungs.

Randy Moe
17-Jan-2019, 06:38
Very wise Neil,

3M makes very good products.

They have a Respirator Selection Page (https://www.3m.com/3M/en_US/safety-centers-of-expertise-us/respiratory-protection/respirator-selection/) which lists suggested options.

I once spray painted a motorcycle with 2 Part Epoxy paint that had cyanide hazard. I bought and used the correct mask, disposable suit, and converted my garage to a filtered spray booth with exhaust fan.

I was unharmed, but will never do that again. I have seen very few old men car painters...


If you're mixing powders, I recommend a full face mask to protect the respiratory system. I bought 3M mask years ago from a local safety supply store. It's easy to update the filters.

I sure didn't want D76 or Dektal powder getting into my lungs.

Steven Ruttenberg
17-Jan-2019, 08:23
Well, as long is it was not gold paint. The huffers say gold paint is the best because of the Tolune (sp) in it is a higher concentration than the other paints.

aaronnate
17-Jan-2019, 14:57
I am no stranger to respirators. Purchase a new one at the beginning of every summer and tend to go through many different grades of filters in the year. I learned a hard lesson when I got in a hurry and forgot to strip the galvinization off some casters before welding them on a table. I ground the weld areas but neglected to strip the whole thing and decided I was only making a few welds and did not need my respirator. Plain stupid and lesson learned.

LabRat
17-Jan-2019, 15:12
I am no stranger to respirators. Purchase a new one at the beginning of every summer and tend to go through many different grades of filters in the year. I learned a hard lesson when I got in a hurry and forgot to strip the galvinization off some casters before welding them on a table. I ground the weld areas but neglected to strip the whole thing and decided I was only making a few welds and did not need my respirator. Plain stupid and lesson learned.

You don't want to weld or heat galvanized, because it releases what looks like microscopic thorns thar look like the barbs on fishhooks, and they embed in yer lungs, so no fun...

You should wear at least a dust mask, but many chems are heavier crystal like, and don't fly around, but some do, but not hard to handle where they stay put...

Some things like galical acetic acid and other strong liquids should be used with a face shield and mixed outside, and never add water to an acid, but a little acid to COLD water at a time to prevent a heat reaction...

Try to find the articles from Darkroom Techniques magazine from the last decades, great formulas and techniques!!!

Steve K

Randy Moe
17-Jan-2019, 15:43
Galvanized Fever aka Galvey fever is horrible.

My last employer refused to replace the welding room power filter vent and I refused to weld anymore. Others were stupid.

Maybe that's why I was forced to pasture...

Drew Wiley
17-Jan-2019, 18:37
Industrial painters have a reputation for short lifespans. Sure glad I didn't open my own industrial paint store. As it was, I kicked out all the true industrial products requiring hot solvent pigments. The bigger problem was finding experienced color matchers whose brains weren't already fried. Toluene and MEK work just like glue sniffing. The damn paint stores had back mixing rooms without fume hoods or really any kind of legal ventilation. Respirators by themselves don't supply clean air. Those guys would seem friendly, normal, and competent, then all of a sudden punch a customer or the boss without even knowing why. One of them stabbed his own brother at the dinner table, and only realized it when he was arrested. Then there's the flammability issue. Not worth it.