stock solution or not

[OmegaB600]

Ilfotec HC

The directions have you make that intermediary stock solution that you then dilute into the final working solution for your tank. Far too many people just take it straight out of the bottle, and skip the intermediary solution. The problem is...

the numbers dont add up.

For some reason the stock solution is 1 part HC +3 parts water.. ie my 200 ml glass bottle needs 50 ml HC and 150 ml water..

That gets diluted into the solutions.. so when dilution X requires 50ml of this stock solution to 950ml water...

How is that supposed to be equaled by using 50ml of pure HC from the bottle?

 

[Freakscene]

50ml of stock + 150ml of water is not the same as 50ml of concentrate + 150ml of water, but to my knowledge no-one says they are.

Ilford says “It is very difficult to measure accurately small quantities of Ilfotec HC concentrate. For this reason, we recommend that the whole bottle of concentrate is diluted to form a stock solution, which is diluted later for use.”

But the stock has a very short storage life, and it is is not that hard to measure Ilfotec-HC or Kodak HC-110 using a syringe. There is a photo of doing so with a bottle stopper syringe and a plain syringe here: Kodak HC-110 Developer - Unofficial Resource Page

So, once you put the measurement issue aside, for example, Ilfotec 1+31 made from 1 part stock (1+3) and 7 parts water, is exactly the same as 1 part concentrate + 31 parts water.

I made the attached table for HC-110 and different size tanks. Never had a problem, including using two baths at 1+50 and 1+200.

Marty

 

[OmegaB600]

Preparing stock developer It is very difficult to measure accurately small quantities of ILFOTEC HC concentrate. For this reason we recommend that the whole bottle of concentrate is diluted to form a stock solution, which is diluted further for use. Stock developer is prepared by diluting the concentrate 1+3 with water.

The table below gives the amount of water and developer stock solution required to make up 1 litre of working strength developer at each dilution. Developer Concentrate dilution

in the ilfotec manual dilution 1+31 requires 1 part stock to 7 parts water. or as they say for a full liter 125 ml of stock solution and 750 ml plain water.

you are not getting the same chemical bath.. mathemtically the 125 ml of stock equates to 32ml of concentrate, and the 1+31 dilution you would have me use would equal the same 32 ml of concentrate, but what you are overlooking is that

that is one of the few dilutions where the math actually give an identical amount of stock chemical. some would have you use far more, or far less then the stock method does.

 

[Freakscene]

Preparing stock developer It is very difficult to measure accurately small quantities of ILFOTEC HC concentrate. For this reason we recommend that the whole bottle of concentrate is diluted to form a stock solution, which is diluted further for use. Stock developer is prepared by diluting the concentrate 1+3 with water.

The table below gives the amount of water and developer stock solution required to make up 1 litre of working strength developer at each dilution. Developer Concentrate dilution

in the ilfotec manual dilution 1+31 requires 1 part stock to 7 parts water. or as they say for a full liter 125 ml of stock solution and 750 ml plain water.

you are not getting the same chemical bath.. mathemtically the 125 ml of stock equates to 32ml of concentrate, and the 1+31 dilution you would have me use would equal the same 32 ml of concentrate, but what you are overlooking is that

that is one of the few dilutions where the math actually give an identical amount of stock chemical. some would have you use far more, or far less then the stock method does.

If you can show mathematically that any base ratio does not hold with increasing volume you should publish your proof as a refutation of the definitions of ratios in Euclid’s Elements Book V (c. 300 BC). That would be quite a feat.

 

[Freakscene]

Volume mixer calculator: Massive Development Chart

I built a Volume Calculator in R Studio, but this does the same thing and it is online in a stable place. It’s useful for calculating stock amounts to avoid needing to use the stock solution with Ilfotec HC, HC-110, L110 and other similar developers.

It might be the best thing on the MDC. At least it’s repeatable, supportable, and not randomly placed there by someone with no experience or idea about what a negative should be like.

 

[maddoc]

When using HC-110, I always make the stock solution (1 + 3) and keep it in the fridge. Storing it this way, it can be used for a couple of weeks from my experience. Much easier and less error prone then fiddling with a syringe and the syrup for me. I use microliter syringes with particle filter to set up solutions of aqua regia in the lab, nasty stuff but the only way to do it. That's why I don't like working with syringes and chemicals.

 

[Freakscene]

When using HC-110, I always make the stock solution (1 + 3) and keep it in the fridge. Storing it this way, it can be used for a couple of weeks from my experience. Much easier and less error prone then fiddling with a syringe and the syrup for me. I use microliter syringes with particle filter to set up solutions of aqua regia in the lab, nasty stuff but the only way to do it. That's why I don't like working with syringes and chemicals.

Apart from using it commercially before Xtol I never used HC-110 much. I just use the syringe method. I syringed hundreds of chemicals for decades, so it’s no big deal for me. But use whatever works.