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I'm looking at mixing up my own paper developer and was wondering whether there are substitutes for Sodium Carbonate (the accelerator, which I presume raises the PH). Would borax work? Or generic washing soda? What PH level should paper developer reach?
Most PQ/MQ paper developers are around pH 10.5 and well buffered. Loading them with sodium carbonate is what does this. There are some alternatives but generally that’s how it is done. Borax alone will not get you to the target pH, but if that’s all you have, the developer will still work - just somewhat slower.
Washing soda is generally sodium carbonate. You'll have to figure out if your particular washing soda is monohydrate or decahydrate. There are ways to do this; just google. Photographic formulas generally call for the monohydrate; if you happen to have decahydrate, you just use more of it according to the molar mass conversion weight. Again, google it.Quote:
Originally Posted by jimskelton
Some paper developer formulas call for just sodium carbonate, some call for hydroxide in addition to this, especially concentrates. For instance, look up the formulas on ID78 concentrate. http://www.lostlabours.co.uk/photogr...rs/devID78.htm You'll see the working strength formula calls for sodium carbonate, while the concentrate calls for potassium carbonate and sodium hydroxide. This is because there's a solubility limit for anything you chuck in there and the solubility limit for sodium carbonate is too low to make a useful concentrate with it. The potassium species is more soluble in water, and hydroxide is added to this as a partial replacement to further increase the strength of the concentrate so that when diluted to working strength, pH will end up the same as the first formula.
Borax as Michael says will result in a lower pH; in fact that's why borax has always been very popular in chemistry circles as it conveniently makes a buffer at around pH 8.20 if memory serves. That's way low for a paper developer, but it's exploited in XTOL and its DIY clones, which is the lowest pH developer (at least common one) I'm aware of (with the exception of some Amidol developers). For film of course, not paper.
pH BTW will be different depending on which developer formula you mix and should be listed along with the formula. For paper, it's not critical. The developer will be a little faster or a little slower, but you develop to completion anyway, so what gives. For film, pH is critical and for B&W you want to keep within +/- 0.1 of the target and for color developers even closer.
FYI: I use washing soda (sodium carbonate) from the supermarket and drain cleaner from the drugstore/DIY store/wherever (sodium hydroxide) all the time for photographic chemistry. Works just fine even though some people say that there will be trace impurities that mess things up. Well, so far, I must have been exceptionally lucky then. Or, more likely, chemical production processes these days are pretty high-quality and generally yield good purity even for lowly applications. Maybe things were very different 50 years ago. In general, many things from the supermarket, drugstore or whathaveyou can be used to good effect as a source for darkroom chemistry. For my self-mixed XTOL clone of course I just use vitamin C from the drugstore; why bother getting technical grade ascorbate if a supply of good purity is literally around the corner? It's like this with many things. Need sulfuric acid for ECN2 stop bath? Battery acid does the trick and is of a known concentration. At one point I needed nitric acid because I was experimenting with wet plate; turns out it was used as a nutrient source (highly diluted!!!!) for hydroponics! Even fixer can sometimes be had cheap; if you're looking for ammonium thiosulfate, again look at fertilizers, as it's used in that application as well. (Although generally, ready-made fixer is cheap and there's no good reason to make your own; just saying).
Have fun mixing your own stuff; for some things, it kind of makes sense sometimes, although often it's not really cheaper and certainly not more convenient than just buying something ready-made. Things like fixer and to an extent also paper developer are pretty economical if you buy them from one of the existing manufacturers. On the other hand, mixing your own is fun, and gives you of course a lot of flexibility in trying things out that would otherwise be costly or virtually impossible if you have to buy everything you'd just want to try once.
Bite the bullet and get some sodium carbonate. It's a lot less hassle than scrounging around for substitutions. It's readily available in many forms from many suppliers.
Washing soda is the decahydrate form of sodium carbonate and can be used in just about any paper developer formula after converting the amount from the monohydrate amount given in the formula. Multiply the weight of the monohydrate by 2.3065 to get the proper amount of decahydrate (the extra weight is all water bound up with the carbonate).
If your formula calls for anhydrous sodium carbonate, multiply that weight by 2.698 to get the equivalent.
Best,
Doremus
Another rabbit hole: Jay DeFehr offers the choice of Potassium Carbonate or Sodium Carbonate for his Obsidian Aqua part B film developer. PC 13g = SC 10g. PH is slightly lower for PC.
A decade ago I settled on Ilford PQ which WAS named the Universal Developer
I use it by the liquid gallon
on any paper
some OLD film and plates too
NOT one shot, it can be used over and over if stored in floating lid tanks
Magic bullets not my preferred weapon
I dislike any powder
My lungs have vastly improved since I retired 14 years ago, from a huge, dusty, AIR CONDITIONED factory. TEST LABORATORY
My horrible loud hacking cough is GONE!
took years and a move to better AIR
What CPAP CRAP...no longer
I have read where Pot Carb. substituted for Sod. Carb will increase the warmth of the print, I did not find that to be true. Further, more Pot Carb is needed to achieve the same paper speed. As had been suggested, stick to the published formulas and make images and prints.
Pool supplies store. Sodium carbonate monohydrate is sold to adjust the pH of pools. Cheap.
Watch this
Darkroom Diary - Amidol vs. Dektol Ultra Large Format Prints
https://youtu.be/vNIo5G9H6HQ
There are all kinds of amidol formulas; but it's instantly apparent that he was using that cheapo Chinese amidol that leaves an overall stain unless the print is extra-washed afterwards. In other words, a potentially misleading comparison test unless one deliberately wants to work with a nearly opaque wretched orange-colored amidol solution. Rumor was it was cooked up in nickel-plated vats which contaminated the whole batch. Dunno. A lot of it got around, even from Formulary. A headache to work with. I found high-quality Euro amidol once again at Artcraft in NYC.