reusing d76 question

[ampguy]

I plan to develop 4 35mm rolls shortly in 2 tanks, because all I have are 4 reels, and 2 tanks.

Can I reuse the 1:1 mixed D76 from the first session and use in the 2nd tank, maybe adding some time?

The times are not too critical for what I'm doing, the time, depending on temps without the "used" factor is already roughly 12-14 minutes.

I plan to reuse the fixer as well, and am thinking of just adding on a minute to the 2nd tank for developing time since the developer will be "used"

make sense?

 

[tmfabian]

i think you may exhaust your developer pretty quickly in that second tank...meaning extra time will do nothing. But then again that's just my gut talking...someone else surely will have some exacting numbers to tell you shortly.

 

[cosmonot]

As long as you have the minimum volume of developer needed for four rolls, that would probably work. I have no idea what that volume is for D76... Why not just reuse undiluted D76 and modify the times?

 

[ampguy]

thanks

thanks

modifying the times is easy. So undiluted d76 can be reused, but diluted is less preferable to reuse (assuming time adjustments)?

As long as you have the minimum volume of developer needed for four rolls, that would probably work. I have no idea what that volume is for D76... Why not just reuse undiluted D76 and modify the times?

 

[oscroft]

I plan to reuse the fixer as well

Most people reuse fixer until it is exhausted. The usual way to tell is to test it on a cut-off bit of film, and if it doesn't clear within half of the normal fixing time (eg it should clear in 2 mins if your fixing time is 4 mins), then it's time to throw it away and make up some more.

 

[drewbarb]

I don't use D76 diluted, so I can't comment on how well it would work to re-use it (though I suspect it would give lack-luster results at best..), but I do know that the full strength developer can be re-used quite successfully, with or without the replenisher. If you use the replenisher, you don't need to extend development times, but even without it, re-using the dev is fine.

As long as you can get times long enough to ensure even development (say, at least 5 minutes with regular by-hand agitation; I assume you might be ok with less time in a machine which gives more regular agitation) in the full strength developer, it seems more economical to use it that way than to dilute it, which basically necessitates single-shot use.

 

[ampguy]

Thanks, I processed some Reala 100 and Agfa 200 C41 color in undiluted D76 for 12 minutes at 68 deg. F. I gave the 2nd tank of 2 reels about 30 seconds extra and some added agitation. Negatives look fine, should have them scanned soon (to grayscale).

 

[venchka]

All this talk of scrimping and saving with D-76 has me befuddled. At $6/gallon or roughly $0.375/roll using Kodak's conservative minimum requirements, why not just use it the way intended so that you'll know for sure the film has plenty D-76 to go around?

Ya gotta use it before it goes bad. So use it!

 

[ampguy]

Hi Wayne

Hi Wayne

I'm doing this a lot around kids and pets, and want to minimize the use of chemicals.

All this talk of scrimping and saving with D-76 has me befuddled. At $6/gallon or roughly $0.375/roll using Kodak's conservative minimum requirements, why not just use it the way intended so that you'll know for sure the film has plenty D-76 to go around?

Ya gotta use it before it goes bad. So use it!

 

[venchka]

OK, that's cool too. It still seems to me that mixing up a batch 1:1 for each tank of film won't increase the exposure for the kidlets and pets. Also, you can mix as much as you need for the whole run at one time, say 1 liter maybe for 2 tanks? The 1:1 mix will keep for 24 hours. Use half for each tank of film. Then you'll know that you have fresh developer for each tank of film.

 

[ampguy]

Hi Wayne

Hi Wayne

You're probably right in that the exposure (to the chemicals) would be the same. I guess having recently been notified that the fixer is reusable, and some developers are, I'd see if we could pour back or just use the d76 mix twice (I did this yesterday, but haven't compared the results between first tank and second tank).

I noticed in your earlier post that D76 runs about $0.37 / roll or tank, but last time I calculated it was about $0.05 / roll based on freestyle powder price, mixed up to 1 gal. (128 oz), using 5-6 oz/roll and diluted 1:1. Were you basing the dev costs on a liquid mix stock?

I'll probably take your advice and use fresh developer, 1:1, and just reuse the fixer, testing occasionally.

Thanks.

OK, that's cool too. It still seems to me that mixing up a batch 1:1 for each tank of film won't increase the exposure for the kidlets and pets. Also, you can mix as much as you need for the whole run at one time, say 1 liter maybe for 2 tanks? The 1:1 mix will keep for 24 hours. Use half for each tank of film. Then you'll know that you have fresh developer for each tank of film.

 

[Ronald M]

If you use it 1:1, the chemicals will not have sufficient capacity for a second run.

 

[ampguy]

thanks

thanks

even the fixer?

If you use it 1:1, the chemicals will not have sufficient capacity for a second run.

 

[venchka]

Geeeeeeeeeeeeeeeze, I didn't know there was going to be a test.

Going by Kodak's suggestion for 8 oz. D-76 per 80 sq. in. of film and seeing D-76 for about $6/bag to make 1 gallon 2-3 weeks ago at the camera store...

128 oz. / 8 oz. = 16

$6.00 / 16 = $0.35 / 80 sq. in.

That's the ultra conservative estimate. YMMV.

Kodak lists capapcities for their fixer. It's a lot of film per gallon. Probably more film than a gallon of D-76 will develop. I personally pitch both developer and fixer after a few months. Long before I use it all up. Maybe I need to expose & process more film, hey?

 

[ampguy]

but my tanks are volume limited

but my tanks are volume limited

Wayne,

My dual reel 35mm tanks only hold 10 oz to top of reels, maybe 12 oz to brim, so 128oz of stock from powder @ 5 oz/tank w/ 1:1 dilution yields about 25 tanks/50 rolls. So at $6/bag of powder to make a gallon, that's about 12 cents a roll for developer. I guess one could just stick one reel in and fill to the brim to give more developer / less surface area, but not sure that's really needed?

Again, it's not the cost, but the reuse of the stuff where it works and makes sense, especially the harsher chemicals. Using less and developing more ...

Geeeeeeeeeeeeeeeze, I didn't know there was going to be a test.

Going by Kodak's suggestion for 8 oz. D-76 per 80 sq. in. of film and seeing D-76 for about $6/bag to make 1 gallon 2-3 weeks ago at the camera store...

128 oz. / 8 oz. = 16

$6.00 / 16 = $0.35 / 80 sq. in.

That's the ultra conservative estimate. YMMV.

Kodak lists capapcities for their fixer. It's a lot of film per gallon. Probably more film than a gallon of D-76 will develop. I personally pitch both developer and fixer after a few months. Long before I use it all up. Maybe I need to expose & process more film, hey?

 

[drewbarb]

I won't get into the debate about the cost per roll for D76- it's low enough that I don't care; but I will say that Kodak recommends using the developer at full strength as well as diluted 1:1. When I use D76 (not often these days) I use it full strength, not out of penny pinching frugality, but because it's easy, and works well. I add replenisher at the rates suggested, and use it until it's exhausted.

As for fixer, it's silly not to re-use it. I mostly use Heico NH5 fixer, out of convenience and habit, but I have found that most acid fixers are about the same in terms of working life, convenience, and cost; I recommend using whatever fix is most convenient for you. Anyway, the NH5 bottle states that the service life of 1 gallon of fixer at working dilution will clear 120 8x10 films- roughly the same film area as 120 rolls of either 35mm or 120 film, or 60 rolls of 220, or 480 sheets of 4x5 film, etc. I generally keep a half-gallon of fix mixed up at any given time, and I have found that I can rely on this to properly fix at least 50 films, at which point I recycle it. Using it as one-shot is wasteful of more than just money- but do what ever you want.

Tip: When loading 35mm film onto reels, you generally cut or tear off the leader, so that you have a basically straight edge to begin loading the film, right? Save these leaders in a box and use them to periodically test your fixer. When it gets to the point of needing more the 30-40 seconds to fully clear a leader, recycle or dump it.

 

[ampguy]

thanks

thanks

got it. Yes, I do cut the ends, so I will have those snippets for fixer testing.

So bottom line is that D76 undiluted is re-usable, but like fixer, it needs testing and replenishment. I'll have to read up on this.

Thanks.

Last question - I mix my Kodak fixer 1:1 from the stock made from powder, so it is going to weaken the stock by pouring it back, of course I can test it every developing session, but did I mis-read something, or do folks use the fixer stock straight?

I won't get into the debate about the cost per roll for D76- it's low enough that I don't care; but I will say that Kodak recommends using the developer at full strength as well as diluted 1:1. When I use D76 (not often these days) I use it full strength, not out of penny pinching frugality, but because it's easy, and works well. I add replenisher at the rates suggested, and use it until it's exhausted.

As for fixer, it's silly not to re-use it. I mostly use Heico NH5 fixer, out of convenience and habit, but I have found that most acid fixers are about the same in terms of working life, convenience, and cost; I recommend using whatever fix is most convenient for you. Anyway, the NH5 bottle states that the service life of 1 gallon of fixer at working dilution will clear 120 8x10 films- roughly the same film area as 120 rolls of either 35mm or 120 film, or 60 rolls of 220, or 480 sheets of 4x5 film, etc. I generally keep a half-gallon of fix mixed up at any given time, and I have found that I can rely on this to properly fix at least 50 films, at which point I recycle it. Using it as one-shot is wasteful of more than just money- but do what ever you want.

Tip: When loading 35mm film onto reels, you generally cut or tear off the leader, so that you have a basically straight edge to begin loading the film, right? Save these leaders in a box and use them to periodically test your fixer. When it gets to the point of needing more the 30-40 seconds to fully clear a leader, recycle or dump it.

 

[venchka]

Don't know about Kodak Fixer. I use Kodak Rapid Fixer. I add half the hardener. Some say no hardener for modern films. Some say use hardener for Efke film. I have some Efke film. So I spilt the difference with the no/yes hardener folks. Anyway, the Rapid Fix out of the box/bottle gets diluted to make 1 gallon of film fixer. That soultion can then be diluted 1:1 for paper.

Drew's fixer numbers match Kodak's numbers for Rapid Fixer. Like I said, a lot more film can be fixed than developed if you start with a gallon of each.

Did that help any at all?

 

[drewbarb]

Sorry- I can't help with the question about that Kodak fixer, since I haven't used it in almost 20 years. There should be information on the package indicating exhaustion rates, at least for the recommended dilution- and probably for full strength use, too.

However you employ whatever fixer you use, you should test it to find it's capacity, and be sure to stop using it before it reaches silver saturation (and thus exhaustion). Until you learn the numbers you can rely on, test a lot. Once you know how much film you should reliably be able to fix with a given amount, you can greatly reduce- or even eliminate (though I wouldn't recommend it)- how much testing you need to do.

About fixers and hardeners, I'm with Wayne. I use rapid fixers, and even though I know hardeners are not really necessary with most modern films and papers, I use some anyway. It doesn't hurt (as long as you wash properly) and clearly can help some films. Besides, I always use a Perma-wash (fixer reducer), with a short water wash before it and a longer one after, so I know I'm getting my materials clean.

 

[ampguy]

Thanks Wayne and Drew - went back to the Kodak data sheets and it pretty much references using the fixer with film at working solution, so I'll stop the 1:1 and use it straight, but pour back and test frequently.

May get rapid fixer next time.