On October 14, 2004 09:14 am, John Black wrote: > > JB, I'm using water stop, not acid stop. > > > > I'm using Formulary TF4 diluted 1:3 with distilled water. > > > > That surprises me that TF4 might be so weakly alkaline.. that's almost > > neutral. > > I'm not absolutely sure about the pH. I think it's in A&T but I loaned my > copy to a friend. I just emailed him to look it up. We'll see. TF-3 is just sodium metaborate and sodium sulfite. According to the 20 mule team people a 0.5% solution of Sodium metaborate gives a pH of 10.8 at 20C. So the question is how much does the hypo and sulfite change that? Nick ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.