HC-110: Stock Solution vs. Concentrate

Is there any advantage in making HC-110 1+3 stock solution and then diluting it

1+7 (or 1+15, or whatever) prior to use, instead of mixing the working solution

directly from the concentrate? <br>

I've been mixing dilutions B and H directly from the concentrate, with great

results. That's why I'm wondering why Kodak recommends making the intermediate

stock solution and says nothing about using the concentrate directly (which

seems to me to work just fine). I can see the disadvantages of using a stock

solution (worse keeping properties than the concentrate, more bottles to store

on the shelf, more work to do, etc.), but I fail to see the advantages. Are

there any?<br>

Thanks.

You never dilute a stock solution of any photo chemical until you are ready to use it. Developers oxidize very quickly when water is added to them, its the oxygen in the water that does it.You are doing it right by mixing it just before use.

The only thing that I can see in Kodak's thinking is that people might have trouble precisely measuring small volumes of the concentrate, especially since it is rather viscous. I have found a syringe gets around this fairly easily.

There is or was a replenisher sold for HC, which would require the stock solution to be useful.

 

It's also possible that the stock solution is aimed at photo labs, which probably used stock solutions. Now I believe most use TMAX.

Some people I met dilute two times because HC 110 is a syrup and they think it'll "mix better". Personally I don't. I did once and lost two rolls of films since I forgot about it...

Well, yes there is a good reason, and it is simply because it is difficult to accurately measure the small amounts of HC-110 syrup needed to make a 1+31 working solution. Think about it. Say you need 300 ml of working solution to develop a single roll of film. At 1+31 you need to accurately measure out 9.375 ml. (300 / 32 = 9.375) of very thick and sticky syrup. Chances are pretty good that you won't be that accurate unless you use a small dosing syringe. You don't need to be off very much in your measurements before the effects of over or under development show themselves.

 

Kodak gives a figure of 6 months storage life for a 1+3 stock solution of HC-110 in completely full and tightly stoppered bottles, so no, it won't go off any quicker than stock solutions of D-76 pr XTOL. According to the tech sheet, which you can find at the URL posted below, there is an HC-110 replensiher still being sold. I do not recommend that the casual home user consider running a replensihed system. A more or less predictable workload is necessary to keep a replenished line operating within spec, and that's not the case for many home users.

 

Reference: http://www.kodak.com/global/en/professional/support/techPubs/j24/j24.pdf

There is no reason to be so precise. Instead of 9.375ml just use 10, or 11 or whatever is convenient... just as long as you have done your testing and are subsequently consistent. I find it easiest to use the syrup without mixing it as a "stock" first. I have been using HC110 syrup at dilution G for years (1:119) by measuring out 3cc's using a small hypodermic needle easily bought at any veterinarian supply. The important part is to be consistent in how you do the measuring.

What Frank said.

 

If you develop more than a roll or two a month there's no disadvantage to using the stock solution. It's more convenient and more accurate - mix once a month or so.

 

If you develop only once a month or rarely use HC-110, sure, the one-shot approach is fine. I've done both for years. But the stock solution approach is in arguably more accurate.

 

Look at it this way: It's absolutely no different from using D-76 or ID-11 from stock solution, which tens of thousands of photographers have done for decades. If anything, HC-110 stock solution is more stable. D-76/ID-11 stock solution can vary a bit over the typical six month working life. Not so much that most folks notice, but enough to be of concern to photographers who are more demanding than average (which I'm not).

Lex, the reason why thousand of users of D-76 have used stock solution is because they had no alternative. But HC-110 offers a very convenient alternative. :-)<br>

<br>

Frank, like Keith said, there's no need to measure 9.375 ml. I'll use 9 ml (very easy to measure with a small syringe), make a few tests to find the developing time, and that's it.<br>

The stock solution may not go off any quicker than D-76 or X-Tol, but it won't keep for years, like the concentrate does. Besides, it only keeps for six months if it's stored in completely full bottles, but in the case of HC-100 the bottle will get emptier with every film you develop (you can't use the stock solution itself and then return it to the bottle, like you can with X-Tol or ID-11 for instance).<br>

<br>

OK, I think I understand. The stock solution approach is better suited to those who develop many rolls of film in a short time, while the concentrate/syringe approach is best for occasional users.

9.375? Could you make that 9.38 or 9.4 without significant difference in contrast? Can you measure your volumes for the stock solution to 1 part in 10000? 100.00 ml of gummy goo to make 400.0 ml of stock? If I can read a 100 ml graduated cylinder to +- 1 ml I'm doing well. Then there's the 500 ml graduate you need to put it all together. Be reasonable! I can get a plunger type syringe at the drug store that will measure the goo as accurately as I need for small amounts of working solution. A 50 ml graduate works for liters or more. The syrup keeps for years, not months.

9.375? No, I mix 10 ml, make 320 mil (or 640 ml) of working solution. Mix well, then I pour out the 20 ml (or 40 ml) of solution I don't need. Just pour the excess right down the drain before I pour what I need into the tank. I always develop with the amount of solution I want at the dilution I want.

 

I probably waste ten or twenty cents worth of HC-110 per year doing it that way. But I do have good consistency.

Bob, did you ever try it with 10 ml to make 300? Can you really tell the difference? Could you make up the difference by cutting the developing time by 5%? Just curious.

Patrick: Actually I consistently use Dil. H or 1:64. I sometimes have two 35mm reels, sometimes 2 120 reels, sometimes up to 5 35mm or 3 120 reels so I'm always mixing different amounts of developer. Sometimes I mix in metric, sometimes in ounces, whichever simplifies the math and gives a little over. But I do try to adhere to the 1:64 ratio as best as I can.

 

Now I know that ratio is not exact given the problems of mixing small quantities of HC-110. I'm sure it varies a few percent all time. Can I tell any difference? Absolutely not. But I also know you are hard pressed to tell a real difference by varying the development time by 5% either.

 

My theory is you try to bring as much consistency as you can to the process without becoming an anal geek about it. Then you just accept what sample variation you have. It's important that remember that if any of this makes a real difference in perception of your final prints, you need to worry about what you are photographing.

Now we agree. I don't use HC110 any more, but I use others that are diluted 50 or so to 1. I say do it the same way every time and learn to use a convenient dilution.

I use HC-110 @ Dil B (1:32) mixing from the concentrate only. When I started using HC-110, I used the stock solution method but found it expires after a few months. So I had to keep make new stock solutions. The concentrate seems to last forever and eliminates this problem. I find mixing the concentrate isn't a big deal if you use English instead of Metric measurements. Based on the 1:32 dilution, that's 1 oz concentrate plus 31 oz water to make a 32 oz working solution. That way you don't have to get all wrapped up with trying to measuring exactly 9.458734 ml (or whatever) amount of concentrate.

In Kodak's original instructions, about 40 years ago, Soln. B was 1:31 from concentrate (I still use it that way, I can measure).

 

Lynn