precision required for the chemical being weighed. Which one I use depends on the quantity vs. To pharmacy scales costing $3,000+ and precision laboratory instruments that are exceeding expensive.Īt present I own two scales, an Acculab V-333 and a DRX-2 Prescriptionīalance. You will require various sizes of graduates for measuring the liquids, a 1.5mlĮyedropper (from PF) for conveniently measuring the Triethanolamine, and a L a b E q u i p m e n t / S u p p l i e s Tinopal SFP is an optical brightening agent that can be used in RA-4, but I'm currently trying to track down a source for it. I've recently seen a replacement stabilizer from Unicolor consisting of Hexamine costing $10.00 for List because it is an easy and effective means of cleaning the sludge thatįormaldehyde may be difficult to obtain in your area. The Sulfuric Acid is not used in any formula, but is included in the chemical ![]() The price listed here is derived from their 1 quart size and adjusted to reflect the equivalent of 454 grams of dry chemical. * Artcraft Chemicals sells its Iron EDTA in liquid form as a 47% solution. Quantites were chosen arbitrarily as a compromise between economy and price, with better savings coming in progressively larger quantities. Where a price is not given, it means that company doesn't sell Other vendors out there, and you likely will find even better pricing if you shop around. Let's begin with a summary of the chemicals involved, and their current pricing from both Photographer's Formulary and Artcraft Chemicals. I've used both, and they have given me consistently good results. In this post I'm documenting a couple of formulas for C-41 and RA-4 that haveīeen requested on the ng. The following informations have been retrieved from the web and particularlyĪn excellent post by William Laut on dated August, 27th 1999. ![]() It will stay fresh as a working solution for 7 daysĥ00ml will make 10 liters of working solutionĪ full working strength solution will produce 150 135-36 or 120 films or 600 20.3x25.4cm (8x10") RC prints or 300 20.3x25.Back to C-41 page Home-made C-41 & RA-4 Chemicals Ilfostop concentrate will keep for 5 years in full airtight bottles and 12 months in half full tightly capped bottles Note:Never let developer become contaminated with a stop bath solution It should be noted that Ilford recommends that gloves, eye protection, apron or overall be worn when handling and mixing all chemicals. It is specifically recommended for dish and tray processing of paper or deep tank processing of film. Ilfostop contains an indicator dye that is pH sensitive and changes color from yellow to purple as the stop bath becomes exhausted. Stop bath gives you the assurance that your developing stage is completely "over" and that none of the developer will be carried over to the fixer. If a stop bath is not available or chosen, the film or print should be thoroughly soaked in a water bath or rinse - with frequent changing of the water supply. ![]() Some people do not use stop bath and, in that case, you must use an inordinate amount of fixer to erase the effects of the developer. The advantage of the stop bath process is that it extends the life of the fixer. This immediately halts the developing process by neutralizing the developer.įollowing this, the film or print is exposed to fixer (hypo). Normally, when development is completed, films and papers are subjected to a stop bath rinse. Ilford Ilfostop is a low odor acid stop bath.
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