Happy thanksgiving for the US folks...I am doing a test run of fp4 and I am using tf4 for the first time. I cannot figure out if it is intended to be used as a one shot fixer or if it can be used multiple times. With the other fixers I have used I have been using hypo check to see if the fixer is exhausted...is it ok to do the same thing with tf4?
Use it multiple times. I use it until it's exhausted; testing with Edwal Hypo Check, or a scrap piece of film. The drop of Hypo Check will turn milky-white in exhausted fix. The scrap piece of film will go clear in a minute or so when fix is still good.
My experience is that the initial clearing time for film with freshly mixed TF-4 is 30 seconds. When the time goes over 30 seconds (tested with a small section of a sacrificial 35mm roll since I use only 120 these days), I dump and mix new fixer. For paper, I also use hypo-check drops as stated above.
Either way. It's an A. Thio. concentrate off the shelf fixer.
As for myself one-shot is the rule. I'm not often in the dark
so one-shot and I don't worry. To give it a try I'd start with
15ml of concentrate and water to make 500ml; a roll of 120.
To be finished within 10 minutes I may need adjust that
initial for starters amount. Dan
Upon occasion when I am using a tank I will add enough TF4 fixer concentrate at the end of development time to make about a 1+7 dilution, pouring out a little developer first if necessary. This fixes in 2 minutes. This method is handy when I am away from home. An 8 oz. bottle fo fixer concentrate, a small bottle of developer concentrate and a 250 ml tank and I'm ready to do 8 35 mm rolls.