John,
good idea with the HQ concentrate. Much easier to handle - something like a concentrated KBr or BTA to dribble in to control fog? Yes, I know, not the same thing, but same idea.

Locally I can't locate propylene glycol but the ethylene glycol is everywhere.

As for the sulfite, which is known to 'regenerate' HQ, and does nothing for glycin - so why add it? 'Save the Planet' 50 years on?

Murray

Big SNIP
Quote Originally Posted by john_s View Post
I always wondered about the Adams HQ addition. It was mixed with a lot of water and adding enough of this solution to approach standard 130 would add an appreciable amount of water an so would dilute the whole thing, probably not what you want if you need a little more contrast. Wouldn't it be better to have the HQ as a concentrate, perhaps in propylene glycol (in which HQ is very soluble)?

Finally, does anyone know why in the AA version, the sulfite is reduced? I can understand the HQ being eliminated, but why the sulfite?