Mixing parts in a Formula

[Arelia99]

Hi everyone! I figure we are all permitted a really dumb question once in a while so here is mine! (Have looked in the forum but cannot find the answer!)


I am planing on trying Pyrocat HD in Propylene Glycol. The regular Pyrocat formula I have seen recommends mixing 1:1:100....so question one: Would the Glycol version be mixed the same way?

Ok: now the really dumb question...What does 1:1:100 actually mean if you want to end up with 400ml of developer? (ie for use in a small tank).

Ok...Thanks for listening!

Nancy

 

[Gerald Koch]

That's what photoformulary says. Dilute 1:1:100 which means 1 part of A, 1 part of B, and 100 parts water. So you mix 4 ml of part A, 4 ml of part B, and 400 ml of water. You will get 408 ml of solution but that's "close enough for government work" as they say.

 

[gainer]

The glycol mix should be diluted just as if it were the water mix.

1:1:100 usually means 1 part Pyrocat + 1 part alkali + 100 parts water. If you make it 4ml Pyrocat + 4 ml alkali + water to make 400 ml you'll never notice the difference. Or, you could start with 400 ml water, add 4 ml Pyrocat and 4 ml alkali and discard the excess 8 ml.

 

[gainer]

While I was meditating my answer, Gerald got his in. So now you have two great minds in agreement.

 

[Arelia99]

Wow! Thanks for the quick replies...I love this place!


Nancy

 

[srs5694]

You could also start with 392ml of water, add 4ml of A and 4ml of B. (Or start with something else, like 300ml of water, add A and B, and then top up to 400ml.) That's not technically 1+1+400 -- it's 1+1+392 -- but it'll be close enough to make no difference in the times you use.