Stop Bath

<p>Long time back I used vinegar as stop bath for print developing, I do not know if it is necessary to use the stop between the developer and fixer while processing B/W film or not and what would be the effect if the stop bath not been used during the process.</p>

<p>Would the food vinegar be good to use as a stop both or not, or it is not necessary in the first place, I am so sorry, this is the best I could manage to explain my need English wise.</p>

<p>Wishing you all of the best.</p>

<p>Stop bath is so cheap, I don't know why you wouldn't just use it. Sure, some people don't use it at all, but personally, I think it is sloppy technique. The two biggest concerns in not using it is contamination of fixer (really, an exhaustion issue), and ensuring that the developer activity stops when it is supposed to.</p>

<p>My friend, we do not have the real film stop bath here, would the food vinegar be a good stop bath agent, thank you my friend?</p>

<p>I use white distilled Vinegar that is 5% I cut it 1-1 to make it 2.5% then use it 1 time then dump it.</p>

<p>A lot of people here, myself included, forego stop bath and use water to stop developement. In a 300 mL tank, a water rinse immediately after pouring out the developer will dilute developer about 1:100. A second rinse, I use two rinses, will then dilute by another 1:100, effectively stopping development. The fixer would then kill any minute traces of developer left in the tank. </p>

<p>My friend <a href="http://www.photo.net/photodb/user?user_id=2163237">Evan Goulet</a>, dp you pplease mean just plain water two times , is this enough , thank you ?</p>

<p >We develop film in a solution that is highly alkaline. After development we fix the film (render it permanent) by bathing it in a fixer solution that is highly acid. </p>

<p >What step after the developer? </p>

<p >1. Remove the film from the developer solution and immerse the film in the fixer solution skipping any intermediate bathe. This works but the life of the fixer solution will be shorted due to the transfer of developer carryover. This is because, if an acid solution directly contacts a alkaline solution, chemically the solutions are neutralized. Thus, we try to avoid direct transfer of the film to the fixer. In addition, along with the neutralization process, carbon dioxide gas is generated. Now the film is in danger of being ruined by the formation of internal gas bubbles and pinholes. Therefore, this is not a good idea. </p>

<p >2. We can use a water rinse. This bathe effectively rids the film of the developer but its action is slow thus some development action continues for a time. This is due to fact that the film is sponge like and retains developer. This action is not uniform as retained developer quickly exhausts in the high-density regions and continues to work for a time in low-density areas. The result is a slight reduction in contrast. Most of the time the contrast reduction is so minuscule a water bathe is quite satisfactory.</p>

<p >3. We can use an acid stop bath solution. This is the preferred method because we can use a very dilute solution of acetic acid. This is ordinary vinegar 1% - 2% strength. This strength effectively stops development quickly by neutralizing the alkaline developer without much gas generation. Additionally, acetic acid is a volatile acid meaning it evaporates away leaving no residue. In addition, acetic acid is one of the constituent ingredients of the fixer solution so stop bath carryover serves to assist the fixers longevity. Thus the use of an acetic acid (vinegar) stop is the preferred method. </p>

<p>Years ago I stopped using stop bath because it would occasionally cause tiny blank spots in the film when reacting with the developer.</p>

<p>I switched to using a plain water bath with continuous agitation for about a minute or two. It works great. Make sure the water is about the same temperature as the developer and fixer.</p>

<blockquote>

<p>We develop film in a solution that is highly alkaline. After development we fix the film (render it permanent) by bathing it in a fixer solution that is highly acid.</p>

</blockquote>

<p>Some of us use an alkaline fixer. <em> </em>For film,<em> </em> I use a water stop bath but only if the fixer is going to be re-used. If not, it's just develop then fix.</p>

<p>Thanks to all of you my friend, My friend Micheal , I have also noticed those spots while using the stop bath after the developer when processing prints, I will use the water continuse water is ok for me , I have the running water in the dark room my friend and I also have heater with temperature controller which I thing will do maintain the same temp. as the other chemical.<br>

I do appreciate all of the technical information given by my friend <a href="http://www.photo.net/photodb/user?user_id=4774668">Alan Marcus</a>, and if the ratio been maintained correctly by mixing the vinegar and the water , it might also not result in causing those spots, it is just I still did not understand in case I do need the stop vinegar bath how much vinegar I need to add to one liter of water, please.</p>

<p>Thank you all , I do appreciate all of the inputs.</p>

<p>It depends on your developing time in my opinion, but I have limited experience developing film. The thought being if your developing time is critical due to the fact that you're not diluting your developer as much as you could and developing times are short then a stop bath is probably necessary. But if you've diluted to the point where the developing time is long, then a few extra seconds for the fixer to neutralize the developer or to rinse the developer off the negatives with water won't really make a difference. You could use it either way.</p>

<p>And your English is fine.<br>

Dan</p>

<p>Not knowing Rashed's exact process, chemicals, etc., it is probably safest to recommend that he continue to use a stop bath between development and fixing.<br>

<br />Rashed - asuming you are starting with 5% distiled vinegar, you should use 0.5-1 liter of 5% acidity vinegar to 1 liter of water.</p>