Bauchet B&W Reversal Processing

[Ian Grant]

First Developer

Part A
Sodium Sulphite (anhyd) 50g
Hydroquinone 15g
Sodium Carbonate (anhyd) 10g
Potassium Bromide 8g
Water to 950 ml

Part B
Sodium Hydroxide 19g
Water to 50 ml

Mix Parts A+B before Use

Bleach Bath

Water 750ml
Potassium Dichromate 6g
Sulphuric acid (conc) 10ml
Water to 1 litre

ADD THE SULPHURIC ACID TO THE 750ml SLOWLY, DROP BY DROP.

Clearing Bath

Sodium Sulphite (anhyd) 100g
Water to 1 litre


Second Developer

Metol 2g
Sodium Sulphite (anhyd) 10g
Hydroquinone 6g
Sodium Carbonate (anhyd) 25g
Potassium Bromide 2g
Water to 1 litre


REVERSAL PROCESSING

First Developer
4-14 minutes at 20°C Development by inspection was recommended
However 8-10 minutes would be a more appropriate as a starting point.

Wash 5 mins

Bleach 3 - 5 minutes

Wash 5 minutes in running water

Clear 3 minutes

Wash 30 seconds

Re-expose - 1 min, 75w bulb at 5 ft (1.5 metres)

Second Developer
To Finality (approx 3 mins)

Wash 30 secs

Fix in normal acid hardening fixer.

Wash 15-30 minutes

[Greg_E]

Thanks. Instead of exposing the film to light, do you know of a way to use another chemical bath to do the same thing?

Also what about using different acids instead of the Sulfuric? Sulfuric is getting to be too much hassle to use, too much paperwork involved to get it. And shipping expense can be very high since it is a hazardous material.

[Ian Grant]

The alternative to re-exposure are to come, there are plenty of different alternatives but they need a completely separate listing.

You can buy conc Sulphuric as drain cleaner US/UK with no paperwork so lets use what's best

Ian

[Greg_E]

Not anymore in the US. Even the lye base drain openers are mostly gone. Can't even buy dilute sulfuric battery acid in the automotive parts stores. I assume I might be able to get sulfuric from the single photo store in town that still carries a good supply of chemicals, but I'm not sure. The damn government has taken most all the good chemicals away from us lately.

Sorry for the rant.

[Paul Verizzo]

Originally Posted by Greg_E

Not anymore in the US. Even the lye base drain openers are mostly gone. Can't even buy dilute sulfuric battery acid in the automotive parts stores. I assume I might be able to get sulfuric from the single photo store in town that still carries a good supply of chemicals, but I'm not sure. The damn government has taken most all the good chemicals away from us lately.

Sorry for the rant.

It was only yesterday that I discovered that Red Devil Lye is gone-ola by several years. About the time I bought my last.

After a lot of internet searching I found the Lowe's has a 2 lb can of Roebic Crystal drain cleaner (IIRC) for $8.

You might be able to get battery acid still from NAPA.

You can also get weaker sulfuric acid from sodium bisulfate, aka pool pH decreaser. $6 for 3 lbs, typically. I use it for stop bath. And the pool.

[amuderick]

You might find this listing of chemicals and common sources useful:
http://www.sas.org/tcs/weeklyIssues_...re2/index.html

[domaz]

How concentrated does the sulfuric acid need to be here?

[Ian Grant]

It should be concentrated, 98%, but there's no reason why you can't use less concentrated provided you adjust the amount to compensate.

Ian

[gainer]

You can make either potassium or sodium hydroxide with Slaked lime from the garden shop and either sodium or potassium carbonate. Calcium carbonate is precipitated. Slaked lime (calcium hydroxide) alone is not very soluble.