why does mixing xtol have to be such a pain

Xtol 5L batches mix quite easily to 1 gallon. Here's a paste from a post I made in another thread:

Some years back, I read of someone having longer storage life with their Xtol stock being mixed to a higher concentration. I mix my Xtol into 1 gallon of distilled water in a glass thumb jug, gently rolling the jug back and forth to avoid aeration. I then decant to small brown bottles, topped up as much as possible. I have a spreadsheet-generated grid posted in my darkroom (attached) with the various stock amounts to convert to standard (as if mixed at 5L) 1:0, 1:1, 1:2 and 1:3 for the tank sizes that I use. I've had great luck with this over the years and find it much easier than wrestling with methods to accomplish 5L batches. I like Xtol but it's not my main go-to soup and the extended shelf life for my usage patterns works well for me (I've never suffered a fail to this point).

A couple of photo friends have started doing this and now have flat foreheads for not doing it sooner.

Gerald C Koch said:

When the powder was added to the container it was as homogeneous are possible. HOWEVER due to uneven settling during shipment the this is no longer true. This means that the contents are no longer uniform. It doesn't matter whether you divide it by weight or by volume each of the portions will not longer be the same.

Follow what Kodak recommends.

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It may be even more problematic than this.

As I understand it, there are some photo chemicals that are never made homogenous at the manufacturing stage. In essence, the various constituent powders are added, one by one, to the bag/jar actually purchased by the customer. They then co-exist, in unevenly distributed powder form, until the entire package is added to water by the customer.

Simon R Galley said:

Dear Phelger,

It is NOT a good idea to part mix powder chemicals...in fact its a very bad idea... you may well have half the powder... but not the correct half ? ie all the different chemicals in the correct volumes, mix all then store as a liquid.

Simon ILFORD Photo / HARMAN technology Limited :

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For some reason, Simon, your comment caused my brain to suddenly ask itself: if the common wisdom is that one should not mix up half of what comes in the can or bag, that presumes that the contents of each can/bag is precisely measured. But step back a moment ask ask -- how did that powder get into the can? Some Kodak or Ilford employee is not sitting at a bench weighing out 80g of this and 8g of that, just enough for the can/bag, then starting over again. A production line must mix 8kg of this and 3kg of that, making a large batch of perhaps 50kg I'm thinking. And then what must happen? The manufacturer scoops out enough for a bag/can, which is what we're being told not to do: taking a portion of a total mixture in the assumption that the ratio of ingredients remains the same in each part of the mixture. The only other way would be to have automated machines that can accurately measure the 80g of this and the 8g of that for each can/bag -- but that would seem much slower than producing in bulk and dividing down.

I'm pretty sure I must be wrong, so hopefully someone with experience will tell me how!

There are 3 or more methods of doing this:

1. Multiple additions made to each can or bag of each chemical. Kind of like filling shells from a powder dispenser in the munitions industry, but with multiple heads.

2. Adding all to a huge rotating drum and then mixing like a cement mixer and as it churns away, the proper amount, evenly distributed, is dispensed into each can or bag.

3. A melted slurry of ingredients is made and then sprayed into an inert atmosphere to form beads which are dispensed. This is most commonly used in single part developers to keep the parts from mixing.

Don't worry, it works and has for over a century!

PS, one of the key issues in all of these is to form the right size particle for its density so that they mix as uniformly as possible. Caking and breaking cause problems later on as the ingredients separate.


PE

Simon R Galley said:

Dear Phelger,

It is NOT a good idea to part mix powder chemicals...
Simon ILFORD Photo / HARMAN technology Limited :

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That may be true but I part mix thoroughly by putting all the powder into large maracas and shake to a tape of Gloria Estefan and the Miami Sound Machine.

That has to be sufficiently rigorous mixing, surely?

pentaxuser

If it all fits in one maraca, perhaps. If you are lucky.

Photo Engineer said:

If it all fits in one maraca, perhaps. If you are lucky.

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Luck has nothing to do with it in my opinion. It is all down to the Miami Sound Machine. The first magic bullet for mixing I have found and 99 pages of reasoned argument against this belief will not work

pentaxuser

craigclu said:

Xtol 5L batches mix quite easily to 1 gallon. Here's a paste from a post I made in another thread:

Some years back, I read of someone having longer storage life with their Xtol stock being mixed to a higher concentration. I mix my Xtol into 1 gallon of distilled water in a glass thumb jug, gently rolling the jug back and forth to avoid aeration. I then decant to small brown bottles, topped up as much as possible. I have a spreadsheet-generated grid posted in my darkroom (attached) with the various stock amounts to convert to standard (as if mixed at 5L) 1:0, 1:1, 1:2 and 1:3 for the tank sizes that I use. I've had great luck with this over the years and find it much easier than wrestling with methods to accomplish 5L batches. I like Xtol but it's not my main go-to soup and the extended shelf life for my usage patterns works well for me (I've never suffered a fail to this point).

A couple of photo friends have started doing this and now have flat foreheads for not doing it sooner.

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Why mess about with an archaic volume, the short measure US gallon. Litres are universal and the standard in the scientific world and the vast majority of countries around the world. I have measures marked in US & UK Imperial measures alongside litres and it's so much easier to use the metric system.

Ian

I mix my XTOL in a 10 quart Sterilite bucket. I use my 1 liter graduate and dump water a liter at a time to put markings with a sharpie in 1 liter increments. Works great. I start out with 3 liters of hot water, dump in the powder than use cold water to make 5 liters. I save half of it for replenishment at 70 mils per roll and the other half as the working solution.

if you measure 5 litres into a large container aand mark the level. Then mix your chemical in 4 litres of water and then from a measured 1 litre, add to the 4 litres of stock until it hits the mark. Subtract what you have left in the 1 litre from 5 litres and that tells you how much water you need to make 5 litres of stock.

Or just buy a bigger measuring jug which is marked in litres. You know it makes better sense.

Weight + weight is not equal to volume + weight or volume + volume.

Liquids and solids do not mix up to equal volume. They do in weight.

You do not understand one of the basic facts of chemistry.

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I think that I do. You just aren't reading my posts, so you are commenting on an imaginary scenario, instead of what I actually said. Allow me to quote myself:

My idea was to mix up 5 liters of xtol per the directions, then weigh it. Then, subtract the weight of the powder, and I would then know how much water I had added. I could accomplish the same by metering in the water....
The only problem I can see is if the [xtol] formula changes, my calculations would then be off

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craigclu said:

Xtol 5L batches mix quite easily to 1 gallon.

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It is even easier to mix it in 5 liter batches and store in appropriately sized containers. No need for rocket science thinking here.

BetterSense said:

I think that I do. You just aren't reading my posts, so you are commenting on an imaginary scenario, instead of what I actually said. Allow me to quote myself:

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How big is your wine bladder?

Sent from my Nexus 5 using Tapatalk

I used to buy 5l boxes of wine and reuse the bladders, but I got tired of the cheap wine and how the boxes starting to fall apart after a reuse or two, so I ordered a kit through my homebrew store that has a hard plastic bin for holding the bladders and comes with a bladder plus you can buy spare bladders. This is definitely awesome.

The bladders expand so there is not a well defined volume.

BetterSense said:

I think that I do. You just aren't reading my posts, so you are commenting on an imaginary scenario, instead of what I actually said. Allow me to quote myself:

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Sorry, the quibble was in "weighing" and then "metering". Two different methods and results.

PE

Bladders get weaker as they get older and may become incontinent.

I think you will have a hard time mixing the powder into the water inside of the bladder or opaque jug like the Datatainers if you can't see that it has been dissolved. If mixing the solution in the bladder involves shaking versus stirring, you might run the risk of oxidizing the solution. Unlike James Bond's martinis, this stuff should be stirred, not shaken. PE has stated that mixing weights and volumes is a not a good idea.

I presume you have graduated cylinders or other means of measuring for development. You have stated that you would not like to have another mixing container like the one mentioned in post (there was a url link here which no longer exists) just for mixing XTOL but if you could mix it in a 1 gallon container that would be ok. The starting amount of water for mixing XTOL per the data sheet is 3.75L which is 0.99 gallons. I'm guessing adding the powder will overflow a gallon container. You could try mixing with a starting volume of water that is less than 3.75L such that you would not overflow the gallon container. The trick there would be getting all of the powder to dissolve in the reduced volume of water. I have difficulty getting the powder to dissolve in my larger container. If you were able to get the powder to dissolve in a 1 gallon container, you could use your graduated cylinder to transfer the solution to the bladder, measuring it as you put it into the bladder, and making up the remaining 5L as you transfer it.

You can do these experiments or you can just spend the $26 on the Doran container mentioned in post #14. Buy a few rolls of film to push you over the $49 limit at B&H and your shipping will be free. I do use that Doran container for mixing and use it for storage when I am not using it for mixing.

Good luck!

Regards,
Rob

Photo Engineer said:

There are 3 or more methods of doing this:

1. Multiple additions made to each can or bag of each chemical. Kind of like filling shells from a powder dispenser in the munitions industry, but with multiple heads.

2. Adding all to a huge rotating drum and then mixing like a cement mixer and as it churns away, the proper amount, evenly distributed, is dispensed into each can or bag.

3. A melted slurry of ingredients is made and then sprayed into an inert atmosphere to form beads which are dispensed. This is most commonly used in single part developers to keep the parts from mixing.

Don't worry, it works and has for over a century!

PS, one of the key issues in all of these is to form the right size particle for its density so that they mix as uniformly as possible. Caking and breaking cause problems later on as the ingredients separate.


PE

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Thanks, PE -- I'd thought of #1 on the basis of having watched many episodes of "How It's Made"; I can see that with #2 some small variances may be possible but are swamped by the high overall volume being drawn from; and I'd not thought of #3 at all -- that's very interesting!

RobC said:

Bladders get weaker as they get older and may become incontinent.

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Also as they become older they have to be emptied more often.

How many of you folks have had a colonoscopy recently? This week I discovered that the bottle for the prep mix is exactly 5 liters. It even has a 4 liter line marked on it. It is white and some what see through so undissolved powder is visible. It is perfect vessel for mixing 5 liters of Xtol. After all the prep is a powder. You pour water in and shake it up and bingo..two and one half hours of slugging the horrible stuff.

A great dark room addition.
It is almost worth having a colonoscopy!

jtcliff said:

It is almost worth having a colonoscopy!

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OK...

Whatever turns your crank!!??

Just another bad case of GAS.

jtcliff said:

How many of you folks have had a colonoscopy recently? This week I discovered that the bottle for the prep mix is exactly 5 liters. It even has a 4 liter line marked on it. It is white and some what see through so undissolved powder is visible. It is perfect vessel for mixing 5 liters of Xtol. After all the prep is a powder. You pour water in and shake it up and bingo..two and one half hours of slugging the horrible stuff.

A great dark room addition.
It is almost worth having a colonoscopy!

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No, I would rather buy a paint bucket, mark it for 5 liters and buy five one liter bottles.