How to make MYTOL without Sodium ascorbate and Kodalk

[rui_lourosa2]

Hello, i would like to know if there are by any means to exactly

duplicate Mytol formula without sodium ascorbate and kodalk, because

exactly these two chemicals are the more expensive and i have to

order them from Artcraft, i have access to ascorbic acid, borax,

sodium hidroxide, carbonates, almost everything, but kodalk and

ascorbate.

thanks

 

Rui Lourosa

Portugal

[silent1]

You can make sodium ascorbate by reacting the ascorbic acid you have with sodium hydroxide (lye), which is probably available in grocery stores (even in Portugal) as a drain opener. Use proper precautions; lye is hazardous stuff: when mixing with water, always add the lye to the water, rather than the other way around, to avoid spattering if the heat of solution causes the water to boil; wear goggles (a single drop of lye solution in your eye will blind you, and the damage is done too quickly for an eye wash to save your sight in most cases) and rubber gloves, and keep a source of fresh water close by, just in case. It'll require some knowledge of chemistry to determine the correct mixing ratio, and I'll leave that up to you -- my reference materials are buried, and it'll be a good exercise in any case. If you know the correct ratio and the solution strength of your sodium hydroxide solution, you can react the two in place as you mix your Mytol -- that is, add the ascorbic acid and then the lye solution; the reaction will be nearly instant when the two liquids mix (but you may need to vary the order to keep acidity or alkalinity within limits or prevent creating a situation where the intermediate product deteriorates quickly -- I'm not familiar with Mytol at all).

 

Kodalk is, IIRC, sodium perborate, also known as borax, though I don't know the solution strength. The borax you have is most likely the decahydrate (that's the commercial version here in America), and Kodalk may be anhydrous, so you may need to correct the weight used for the weight of the water of crystallization.

 

And, of course, with use of hydrated borax and lye solution in making up the Mytol, you'll certainly need to adjust the final amount of water, though it's likely the formula ends with "water to make 1 liter" or similar anyway.

[conrad_hoffman]

My understanding is that Kodalk (Kodak Balanced Alkali) is sodium metaborate, octahydrate. This can be made by reacting borax with sodium hydroxide, though I don't know the proportions. It has an effect somewhere between borax alone and the carbonates. Betcha Pat Gainer and Lex know the exact receipes!

[ole_tjugen]

Kodalk is not borax, but sodium metaborate. there's a suggestion of how to make it from borax and sodium hydroxide (NaOH) on http://www.binbooks.com/books/photo/i/l/5D236AF668&f=1 . In brief, mixing 45.45g borax and 9.53g sodium hydroxide gives the equivalent of 100g sodium metaborate (Kodalk). Do this in water solution, and then add water to 1000 ml to get a 10% solution.

 

There's something similar for the vitamin C: 88.90g ascorbic acid plus 20.19g NaOH gives 100g sodium ascorbate. I don't know the solubilty of this, so I can't suggest a finished volume.

[rui_lourosa2]

ok, what i was trying to know is a complete formula, from top to end, and yes even here in portugal (next to albania, above bora bora) there are groceries with the outrageous dangerly lye, but we call it sodium hydroxide or just caustic soda, for the friends.

[crackers_.]

Lex? I think he uses a dobber of this and a squosh of that in warmed water and swooshes it a spell. Gotta set out overnight.

[lex_jenkins]

Bob's got me figured. I'm strictly a bush-league experimenter, not anywhere near Mr. Gainer's league.

[nicholas_t.]

There <b>are</b> ways of making Sodium Ascorbate as well as Kodalk (actually Sodium Metaborate) in fact there is an interesting discussion going on right now in the rec.photo.darkroom usenet forum right now. The substitution of Kodalk is easier than buying the stuff because you can make more than you can get and IIRC, a 10% solution of Sodium Metaborate either precipitates out or crystallises; whereas the substitute 10% solution does not.<p>

You can substitute the Metaborate without using Lye in the Gainer developers by using one teaspoon each of Borax and Carbonate per litre of film developer.<p>

Making Sodium Ascorbate has been listed here many times as well...<p>

But why? If you have Phenidone or Metol you can make many different developers with what you have in your darkroom already.

[nicholas_t.]

Before I get trolled, it doesn't make any sense that a 10% Metaborate solution should precipitate out and the substitute (Borax/Lye solution) doesn't - if they are equivilent?

[jorge_oliveira2]

Boa noite, Ruy

 

I went through all the troubles to make metaborate - I still didn't find it in small (1Kg) quantities here in Brazil. Even purchased a cheap pH meter...

 

Don't. It's too crytical. NaOH is very much hygroscopic, weight changes a lot with humidity absortion, results changes from one batch to the other, metaborate crystals will precipitate, lots of trouble.

 

My last try will be to precipitate crystals, decant and see if after drying they can be used (Sou um teimoso).

 

Now, do you want a Xtol equivalent? Simple, easy, sharp, fine grain?

 

Then mix E-76.

 

http://www.stanford.edu/~cpatton/yingui/e76.htm

 

I use it 1+2. Just as a reference, 125PX @200 - 10 min @20C agitating each 2 min.

 

Boa sorte!

[jorge_oliveira2]

Nicholas

 

A 10% solution may precipitate also. It will depend very much on humidity content of your hydroxude.

 

'Humid' (so, less real NaOH), and pH will not be equivalent to meatborate and will not precipitate; more (so pH is closer to the desired one), and it may precipitate - but as very small (powder like) crystals.

 

A 20% solution (mix borax in hot water so it solves), add excess NaOH (some 10~15%) and you will have very nice, large crystals when cool.

 

Do it the other way around - solve hydroxide, add borax slowly until it doesn't solves anymore, decant, discard excess borax - how much metaborate is there in the solution? Impossible to know, since the real quantity of (dry) NaOH is unknown.

 

All the above does not means it cannot be done - it only means it cannot be done equally in a repetitive way (Damm, why did I work with ISO 9000 certified companies).

 

Another thing I have not tested - purchase already mixed NaOH solutions. They may be more stable, but I did not fell at easy having a 2 liter bottle of 50% solution around, and my chemical storage cabinet is full.