Hydroquinone staining formulas

[karavelov]

Hello,

I am finishing my bottle of PCQ-TEA film developer and I have to mix a new bottle. It is staining hydroquinone-phenidone-vit.C that gives me very good negatives with dark brown stain.

I would like to mix now Pyrocat-MC type of developer, but a have not pyrocatechin, it is not cheap to order it here in Bulgaria. So I would like to substitute it with hydroquinone (Patric Gainer was experimenting with good results). What is the ratio for substituting catechin with quinon? And do you use other developers using hydroquinone as developing, staining and tanning agent?

Thanks in advance
luben

 

[Tom Hoskinson]

A Metol/Ascorbate developer that contains low sulfite or no sulfite will produce image stain.

I have 2 suggestions:

1. Send a PM to Patrick Gainer.

2. Mix the Metol/Ascorbate component of Pyrocat-MC, add Hydroquinone instead of pyrocatechin and test the result. Hydroquinone will produce a lower activity than pyrocatechin.

 

[psvensson]

A Metol/Ascorbate developer that contains low sulfite or no sulfite will produce image stain.

You're referring to one that also contains something that stains more strongly than metol, right?

 

[Tom Hoskinson]

You're referring to one that also contains something that stains more strongly than metol, right?

No, I refer to a developer that contains Metol, Ascorbic Acid, Alkali and water. The alkali source can be TEA (Triethanolamine).

 

[psvensson]

No, I refer to a developer that contains Metol, Ascorbic Acid, Alkali and water. The alkali source can be TEA (Triethanolamine).

So do you get noticeable stain with the developer you posted here? (there was a url link here which no longer exists)

Or do you omit sulfite completely? I get only a shadow of development from MC-TEA if I don't add sulfite.

According to Helen B's post (there was a url link here which no longer exists), metol produces only one fifth as much stain as hydroquinone, so I'm very surprised its noticeable. I may try it with my MC-TEA.

 

[Tom Hoskinson]

Yes, I get noticeable stain with this formula: (there was a url link here which no longer exists) If I add a teaspoon of Na2CO3 to the working developer, I get more stain.

I have some visual channel versus blue channel densitometer measurements - I'll look them up and post them.

I would expect to get more stain if I added some pyrocatechol or hydroquinone to the mxture.

 

[gainer]

A Metol/Ascorbate developer that contains low sulfite or no sulfite will produce image stain.

I have 2 suggestions:

1. Send a PM to Patrick Gainer.

2. Mix the Metol/Ascorbate component of Pyrocat-MC, add Hydroquinone instead of pyrocatechin and test the result. Hydroquinone will produce a lower activity than pyrocatechin.

I don't think it will be much less active than catechol. Even here in the US it is a lot less expensive than catechol. It all depends on whether the color of the stain is useful to you. I think it still shows different contrast for graded or UV sensitive paper and VC paper, but could be wrong.

Substituting metol for phenidone one should remember that the molecular weight of metol is greater than that of phenidone. Much of that is in the H2SO4 attached.

 

[copake_ham]

FYI

http://www.nytimes.com/2006/08/30/health/30brfs-006.html?_r=1&oref=slogin

 

[jim appleyard]

If they ban Q, I'll never get to look like MJ

 

[eclarke]

Jeez!! It seems there is something new everyday that you need to stockpile!!...EC

 

[psvensson]

There's no reason for alarm just because hydroquinone skin creams are going prescription, unless you make your developer from skin cream. Hydroquinone has been prescription-only in Europe for a long time. The FDA doesn't have jurisdiction over photographic chemicals.

 

[karavelov]

Thanks for all the responses. I will try to make HQ-MC following the guides for mixing Pyrocat-MC and I will report my findings next week.

luben