Lith Developer from Scratch; Dilution guidelines?

[Marco Buonocore]

Hello,

I'm about to start making lith developer from scratch. This will be for lith printing. I can't justify spending 50$ for 500ml of LD20 or Moersch chemistry; not when the raw chemicals are relatively inexpensive and used so sparingly.

I'll be making formula with paraformaldehyde. I've found the paraformaldehyde free versions to be lacking on more than a few levels.

I'd like to know people's thoughts on dilution for printing. Should I aim to have a certain amount of hydroquinone per litre of working solution? Should I aim for a specific alkalinity?

I'll probably start with D-85, and try others like Ansco-79B.

Any thoughts on the subject would be much appreciated!

Thanks,

[paul_c5x4]

I'll probably start with D-85, and try others like Ansco-79B.

A while back, I entered the formulas for Dupont LD-1, Dupont D-7, D-85 (both single and two part), Ansco 79, and Ansco 79B in to a spreadsheet to compare the chemical ratios. All five contain identical quantities of Boric Acid, Hydroquinone, and Paraformaldehyde. Potassium Bromide was either 1.5g or 1.6g, Sodium Sulphite varied between 29.4g and 30.25g - The only difference of note was the use of Sodium Bisulphite (2.2-2.6g) or Potassium Metabisulfite (2.5-2.625g). These numbers are based on mixing parts A & B in the ratios given over on the unblinkingeye lith developers page.

Once you have mixed a batch of which ever formula you choose, there is scope to alter the ratio of parts A and B which may affect the final result - Last time I mixed a batch of D-85, I used it at a dilution of one part A+B (mixed 1A+3B) to 10-12 parts water. Tray life was good enough for a few hours, but capacity left a bit to be desired in my opinion - When things warm up a little and time allows, I have a couple of negs I want to lith print, so will mix another batch.

[Marco Buonocore]

Hi Paul,

I see what you mean about there being similarities between formula; they are all using the same components for the most part. I wouldn't say they have identical quantities, though. Dupont LD-1, for example, has less paraformaldehyde than Kodak D-85. That's going to have an effect on the working solution's alkalinity, won't it?

I wish I could find the source - I dug through all my books in the darkroom - but I remember once reading that an optimal alkalinity for hydroquinone was ph 12. In one of the formaldehyde free formulas that Ryuji Suzuki posted ("Burning Lith Developer") he used a 1% solution of Trisodium Phosphate as the alkaline, giving it a ph of 11.3% (as per the darkroom cookbook - I don't have a ph meter). I assume that was a good working alkalinity for hydroquinone. I was hoping to determine an optimal dilution by keeping things like that in mind. Does that make sense? Maybe not!

It's harder to understand that relationship between paraformaldehyde and alkalinity. I gather that it converts sodium sulfite to sodium hydroxide, which is pretty ingenious. To what extent, I don't know. Maybe a chemist can chime in.

If you ever dig up that spreadsheet, I'd love to have a look at it! Formulas aren't that easy to come by. There's Rudman's 2nd book, the Unblinking Eye site, and this fellow as well. There are a lot of repetitions, for sure.

Thanks!

[Bob Carnie]

I may be wrong here, but the best lith chemical formulations that I have used contained formaldeyde which when the a and b are mixed produced a milky look.

[Marco Buonocore]

Oh I'm with you all the way, Bob. I've tried plenty of formaldehyde free formulas and they just don't cut it. They're not even close. I got a kilo of paraformaldehyde and will be doing some testing down at Gallery 44 - it'll be a good way to slog through February.

[Bob Carnie]

If you get a good scratch mix formula I would love to hear about it.. I like the Moresch 5 and the fotospeed stuff, if you can equal the pop of those then your on to something.

Oh I'm with you all the way, Bob. I've tried plenty of formaldehyde free formulas and they just don't cut it. They're not even close. I got a kilo of paraformaldehyde and will be doing some testing down at Gallery 44 - it'll be a good way to slog through February.

[paul_c5x4]

I see what you mean about there being similarities between formula; they are all using the same components for the most part. I wouldn't say they have identical quantities, though. Dupont LD-1, for example, has less paraformaldehyde than Kodak D-85. That's going to have an effect on the working solution's alkalinity, won't it?

D-85 calls for 37.5g of paraformaldehyde in part B. LD-1 uses 7.5g and is a single solution mix. D-85 is mixed at a ratio of four parts A to one part B, so for every litre of working solution*, it contains (37.5/5)=7.5g of paraformaldehyde. If you do the same calculation on the other ingredients, you'll find the quantities very similar.

*) "working solution" is a little misleading as it requires further dilution with water before use as a lith paper developer.

[Marco Buonocore]

Oh I see; you're right, Paul.

As an aside: I guess once you start to factor in the further dilution that takes place for use in printing, any of the other small differences in these formulas become pretty insignificant.

[WHof]

My Tim Rudman workshop notes for Kodak D-85 say "82.5 millilitres of acetone may be substituted for the paraformaldehyde." Anyone ever try it?

[Marco Buonocore]

WHof,

Lots of information re: paraformaldehyde and acetone out there, you just have to dig through the lousy pure silver forums.

http://www.freelists.org/post/pure-s...h-developers,2

http://www.freelists.org/post/pure-s...h-developers,5

etc...

Paraformaldehyde seems to work so well, I don't see the point in substituting it.