Acetic Acid

<p>Hello everyone.<br>

A formula I use to make a rapid fix for black and white films includes 'Glacial Acetic Acid'. I am having a problem locating this chemical (hazardous). Can anyone suggest an alternative or a replacement.<br>

Thank you</p>

 

<p>Dennis, "glacial" refers to purity and strength, I believe. (My last chemistry class was LONG ago.) I just buy stop bath at the camera store, myself, but when I'm out of stop bath, I use one third standard "white vinegar" (which is IIRC 4% acetic acid) and two thirds water. :-) Smart people will have better answers, but that's my Larry-Moe-and-Curlyesque method. :-) And it seems to work fine.</p>

 

<p>Glacial acetic acid is water free, 99.5%+ acid. You only need a few % solution of acetic acid to make fixer, so much lower concentrations are quite satisfactory, so long as they are lab grade. It is easy to find both glacial and lower concentrations from any chemistry lab supplier or photo supply. The lower concentrations will work just as well and be easier to handle. Just adjust the formula to the dilution level.<br /> But I think a better alternative is any of the the newer odorless fixers.</p>

<p>Forgot to mention, if you are in the US, you can order glacial from Photographers Formulary photoformulary.com</p>

 

<p>The 28% concentration is easier to find, and less expensive ship (not Haz-Mat). You just need to do the right computation to adjust for the lower concentration of the active ingredient.</p>

<p>I bought a lifetime supply, actually probably several lifetimes supply, from photoformulary. It isn't expensive. I diluted some to one liter at 28% because my formulas use that concentration. Be sure to pour the acid into the water, not the other way around. When my acetic acid arrived it was frozen solid, hence the name glacial.</p>

<p>I like 28% because glacial acetic acid freezes at an absurdly high temperature, about 62F, thus the name "glacial". If that happens and the bottle breaks, you've got a serious mess.</p>

<p>You may find it easier to get an 80% solution and dilute that 1+19.</p>

<p>Thanks for all the replies. All very helpful. I was thinking along the lines of 'Distilled Vinegar'. But I cannot see an acid percentage on any of the bottles looked at so far.</p>

<p>Thank you everyone.</p>

<p>I was just wondering if 'Citric Acid' might be an alternative. But what ratio would I use?</p>

<p>Indeed Glacial Acetic Acid is 99,5% and can be hazardous in use. For a regular stop you're going to 1,5% - 2%. (1+50)<br>

When using Citric Acid for a stop you can use 15g Citric Acid in 1ltr. water. This is also pretty odorless.</p>

 

<p>If you need stop bath I suggest you buy the Odorless kind from Freestyle which contains citric acid. It does a good job, does not have the smell and is economical. I may have told this story before but at the end of High School (Ford administration) I took home a heavy and thick 1 gallon container of glacial aceitic acid from the science lab. How did I get it home? The subway! If I tried that today I'd probably be hauled off. Between film developing and printing I used a lot of stop bath but it still took a long time to use all of it up. </p>

<p>If you need stop bath I suggest you buy the Odorless kind from Freestyle which contains citric acid. It does a good job, does not have the smell and is economical. I may have told this story before but at the end of High School (Ford administration) I took home a heavy and thick 1 gallon container of glacial aceitic acid from the science lab. How did I get it home? The subway! If I tried that today I'd probably be hauled off. Between film developing and printing I used a lot of stop bath but it still took a long time to use all of it up. </p>

<p>Thanks for all the responses. I actually am enquiring about a 'rapid fix' formula.</p>

<p>Rapid fixer is essentially Ammonium Thiosulphate plus bits. The acetic acid is there solely to adjust the pH, I suspect. You could easily substitute citric acid if you wish but I would go with a greater amount of dilute acetic acid, as described above.</p>

<p>Would lemon juice work?</p>

<p>The acid in lemon juice would serve as a sort of stop bath, but the oils might be a problem. For best archival practice stick with photographic grade stop bath or distilled white vinegar... and I'm not even sure the latter should qualify as "archival" although I have used it myself.</p>