no problem! i tend to get a little cryptic ;-D
i certainly wouldn't teach anything other than cyanotype like this. even
salt printing requires more precision. my understanding, though, is that
all that's really necessary to make a blueprint is an excess of FAC to
pot ferri, molecularly speaking.
the rest, very literally, all comes out in the wash.
but perhaps i'm incorrect on this point--does anyone happen to know? is
it excess of pot ferri to FAC instead?
cheers,
k
Christina Z. Anderson wrote:
> Good morning all,
>
> It is so nice to see some list action!!! I thought everyone had died or
> something. I almost did finishing up my last semester here at Clemson.
> Only one critique left tonight and I'll be done. However, I am sad it's
> over....:(
>
> BTW, speaking of Clemson and keeping it on the topic of cyanotype, if
> anyone has the book Peek, Sam Wang's beautiful 2 page spread cyanotype
> is in that book's center. It is awesome. (I'm not grade grubbing; he's
> already passed me. Now I can speak about him as my COLLEAGUE heheheh.)
>
> One more note on cyanotype:
>
> Someone questioned inaccuracy of teaspoon measures. My conversions are
> accurate, especially in the larger amounts. If a gram scale can be off
> plus or minus 0.1 g then that can be a big deal in 1/4 tsp measures, but
> not in 1/4 cup measures. I just don't think cyanotype, from all of the
> various formulae out there, needs to be so exact. However, Kris, I do
> use 237 ml for a cup.
>
> The most important thing is this, the gram measures for these two chems,
> and then do the math:
> pot ferri is 1.5, 2.8, 5.5, 8.0, 15.5 for 1/4, 1/2, 1 tsp, 1/2
> tablespooon, and 1 tablespoon.
> FAC is 1.0, 2.0, 4.1, 6.2, and 12.5 respectively.
>
> The other thing: a book here and there will say that once the solution
> is mixed it only lasts a couple hours or blah blah blah, but I have
> heard otherwise. I'm not sure the extent of this, but I have heard up
> to 2 wk with part A and part B mixed. So in other words, throwing
> together a bunch of chems in the morning before Kris' demo will be just
> fine.
>
> Personally, I own my own gram scale, but with cyano I just mix by
> teaspoon and never weigh it out. I find the paper the much bigger
> variable than any variation in measure. And how soon after coating you
> expose. The fact that the blueprintables people are dumping a half a cup
> and a cup of the chems in a bucket of water makes me not be anal about
> my method. And their fabric they sell is gorgeous.
>
> Kris, mea culpa for thinking you had your math way wrong. However, I
> never mix it up like that, always keeping A in regular strength and B in
> regular strength and then having the option of mixing the parts together
> in any way I want. Don't ask me why I do it that way--I never mix the
> parts any differently than 2:1. A creature of habit.
> Chris
>
>> huh?
>> i converted it. i always prefer to make a 1:1 sol'n of cyano, and a
>> two cup batch (when mixed) can do a class for at least a day or two.
>> here's the math:
>> 1 tsp = 5ml
>> 1 tbsp = ~15ml
>> 1 cup = ~250ml
>>
>> to make Christina's A 1:1 (instead of 2:1), just double the ferric am.
>> citrate--10tsp instead of 5 in 100ml
>>
>> then multiply everything to 2.5 (to adjust to one cup water):
>>
>> A:
>> 10 tsp = 50ml > 50ml * 2.5 = 125ml (1/2 cup) ferric am. citrate
>> 100ml > * 2.5 = 250ml (1 cup) water
>>
>> B:
>> 1 1/4 tsp = 6.25ml > *2.5 = 15.625ml (just over 1 tablespoon) pot.
>> ferricyanide
>> 100ml > * 2.5 = 250ml (1 cup) water
>>
>> that makes sense to me; esp. in terms of the quantities i sense i'm
>> working with when i'm mixing by weight.
>>
>> ciao,
>> k
>>
>>
>> ryberg wrote:
>>
>>> Kris,
>>> You'll probably get responses from Christina, but you are confusing
>>> teaspoons (tsp) with tablespoons (tbsp). This is important. You are
>>> using
>>> three time too much, or maybe even more.
>>> Charles Portland Or
>>>
>
>
Received on Wed May 4 08:48:34 2005
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