Z-man, one of the sites I referenced earlier has the PC-Glycol formula, but not the whole article from Photo Techniques. If you want the whole article, the magazine sells back issues, although I can't promise the relevant one is still available. (It was when I bought it a couple of years ago.)
Concerning using automotive anti-freeze as a source of glycol, I've seen some people caution against this because you don't really know what's in it, and therefore whether the additives could have negative photographic effects; however, I have yet to see a report of it causing serious problems. I mixed up some PC-Glycol using "eco-friendly" anti-freeze in May of 2005 and it's still going strong. I've also bought various chemicals, including ascorbic acid, from The Chemistry Store, which Gadget Gainer has just referenced. They seem reliable and inexpensive, although their shipping charges are a bit on the high side, IMHO. (They tack on a separate "handling" charge, IIRC, which they don't mention until near the end of the order process.)
good info all around
gadget you are priceless
Originally Posted by gainer
i remember when you published the original articles-but my collection of back issues is no more
do you remember the guy who worked out a paper emulsion based on copper? he used pool supply copper sulphate-or was that you?
re my issues with crt placement-my new apt(3 yr old bldng!) walls and ceiling cant handle standard industrial mnts! am trying to find one of the desks that mnts the monitor with the screen looking up at you-just like you are reading a book-i'm good if i look down-thanks for the input on that
i went to nowfoods.com but all i get is a list of stores in my area and they all don't have the ascobic acid powder-i had hoped to order direct from the site but no go
so now i can look forward to both bastille day and gadget gainer's 80th-this will be a memorable event
vaya con dios
I think that if you look at the Chemistry Store web site you may find enough things you want to make the shipping cost worthwhile. Be aware that erythorbic acid is an isomer of ascorbic acid that functions just as well in photo chemistry and may be a little less expensive. Also, ascorbic acid is available in two grades, the cheaper of which is not to be used as vitamin C, perhaps because it is a mixture of the isomers.
They can put a gallon each of propylene glycol and TEA plus several pounds of other stuff in one box, which sometimes makes the shipping cost per pound go down.
Would a borax second bath give finer grain? I tried searching for catechol and borax, and I found a note on incompatibility, but details were scant. Can anyone help? Thanks!
Threshold of development of pyrocatechin is reported about 9.5,see last post here:
pH of Borax is about 9.2, sodium metaborate 11.1.
Metaborate might work with long development.Place your bets.
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