HC-110 failure?

[michael_schiller]

Hi All.

 

I have a strange problem. I bought a 3.5 gallon bottle of HC-110 (that's how much it will

make, not how much syrup was in the bottle!) less than 2 months ago off ebay. The bottle

was brand new, still sealed, in it's original box, etc. but it was the older square style bottle.

Well, I mixed it up into the stock solution, then after noting that supposedly the dilution A

has the same keeping qualities as the stock I further mixed up 5 litres of dil A, and had

just about 2 litres of stock solution left. I filled a 2 litre soda bottle with the stock, and put

it away in a dark closet, and put the mixed A into a 5 litre bottle with all my other

chemicals, using it to mix dilution B for use.

 

At first everything was fine, I used some of it at dilution B to process various 4x5 sheet

films, and I really liked that it reduced the amount of base fog on some of the older

expired film I have here. In one test I did, I compared HC-110, Rodinal, and DK-60a with

30 year old Plus-X, and it had the least amount of base fog of the bunch (Rodinal came in

second, and DK-60a had all the base fog you could want!) Now the problem...

 

All of a sudden the HC-110 seems to have lost it's strength. Negatives were coming out

real thin, regardless of if I was using old film, or fresh film. I first noticed this when I

developed some 4x5 Ektapan for a friend who just got his first Crown Graphic, and had

taken some shots using some large flashbulbs he has. Naturally I assumed that his

figuring of the flash guide numbers was off, as I've developed lots of film, and did his the

same way I've been doing it, so it couldn't be the developing! Well, soon after I noticed

that my own stuff was coming out too thin using HC-110, but was fine when using either

Rodinal, or DK-60a. I then tried using dilution A but at the same times as I had been using

for B, and the negatives come out pretty good. I figured that my diluted A had for some

reason or other gone bad, so I dumped it, and mixed up a small amount of B from the

stock solution I still had put away, again, it was no good. Just today I mixed up some A

from the stock solution, developed some Arista .EDU 400 film in it for 7:30, and the

negatives came out fine, but by all rights, they should have been way overdeveloped.

 

Has anyone else ever seen HC-110 suddenly get weak? I mixed the stock solution (and all

the further dilutions using distilled water, so my horrible city water didn't enter into the

picture. Any advice would be appreciated, and sorry for the long post!

 

-Mike

[michael erlich]

I always mix HC-110 directly from the syrup using a syringe to measure small

quantities, and I use it one-shot. I've been using the same bottle of syrup for more

than 2 years with consistant results. I just make sure to expell all the air from the

syrup bottle before sealing.

[ronald_moravec1]

Soft drink plastic bottles are not necessarily air tight. There is a membrane imbedded into the plastic designed for different things.

 

I always mix from scratch too. No predilution. The first time I open a new bottle, I put it into 4 120ml bottles. New round bottles are marked with 2 yr expiration dates. I have heard it goes from ok to no good fast when you keep using the same stock. If you want to work this archaic way, buy a densitometer and control strips.

[r._odinal]

As already mentioned, it's not common practice to mix and store developers in their dilluted (working) form. I once mixed some HC-110 stock solution and kept it for several months with no problems. But other times I always mix from the the syrup right before use. I'd also recommend to stay away from soda bottles for storing developer.

[patrick_gainer]

HC110 syrup is remarkably resistant to oxidation. It will not develop film until you add some water. The precaution of squeezing the air out only serves to prevent dilution by atmospheric moisture. The active ingredients of HC110 concentrate are contained in organic solvents, which do not allow ionization as does water.

 

As soon as you add water, the HC110 becomes active and is subject to aerial oxidation. A very small amount of oxygen is then equivalent to a very large amount of film in terms of the amount of developing agent it can use up.

 

Putting the concentrate in small bottles is not a bad idea. It will allow you to use the mdeicine syringes that look like hypodermics but will not accept needles. You can get them at most drug stores in a package with a tapered rubber stopper with a hole for the syringe. You can leave the stringe in the hole as a stopper and measure out up to 10 ml at a time very accurately. Since the HC110 is not subject to aerial oxidation, the amount of air you may squirt in will have no deleterious effect on the developer during your lifetime.

 

HC110 is dangerous if handled carelessly. It has some components that can cross the skin barrier, IIRC.

[tonghang_zhou]

I make a 1+1 stock from concentrate, which I then dilute 16X to make dilution B as needed. Less water, hopefully last longer. Still I wouldn't keep it (the stock) for more than 2 months. It develops a very slight red tint when it's about 2 months old. That's your sign to make fresh stock. Also, use glass bottles, use plastic wrap material under the cap to seal better, and use 'Dust-Off' or other canned "air" to fill bottles that are not full. HC-110 is so cheap, no need to take any risk. In concentrate form, it probably keeps forever.

[tonghang_zhou]

<blockquote><i>"HC110 is dangerous if handled carelessly. It has some components that can cross the skin barrier, IIRC."</i></blockquote>

 

Patrick, do you mean HC-110 is <b>more</b> toxic than other main stream developers, such as D76, Microphen, Rodinal, Diafine? I guess we can exclude the extreme cases of Pyro and Xtol (or Gainer's formula.)

[patrick_gainer]

If we believe the label on the bottle, yes. I've used it off and on for years with no problem, but there's always a first time. The warnings are probably for industrial users who are more or less continuously exposed to it, but it won't hurt to take care. I doubt there is a serious threat to the environment outside the darkroom from most of us.

[al_divenuti]

The Covington Innovation's site for HC-110 suggested that HC-110 is actually less toxic than most liquid developers. In fact, I think the term "Unusually Environmentally Friendly" were used on the page.

 

Oddly, the replenisher formula for HC-110 contains pyrocatechol. And as toxic agents go, it's hard to do worse than that one.