I have committed to scratch mixing as many chemicals as I logically can. As Kirk noted, selenium powder is reputed to be extremely dangerous to handle, so I will stick with premixed. Awhile back I costed out the bulk chemicals to make TF 3 (or maybe 4, can't remember now) vs. buying TF4 or 5, and unless I calculated wrongly, the savings were so minimal that I decided to stick with premixed. And I can't find a lith developer formula that works as reliably as premixed, but everything else is scratch made.
What working dilution for working
Originally Posted by pcyco
recommended is no dilution
but film clears in the stocksolution within appr. 30 sec.
i´m sur it works also with 1+1 or 1+3
The pH range he gives in his post indicates it is acidic. It is the post he is quoting that says it is alkaline.
Originally Posted by bdial
I have had quotes from Nymoc (John, I think was his name) in the past.
I found that Claire, the Formulary,and Artcraft had him beat on price by quite a margin when I was stocking up on dry chems for the mix from scratch stocks 3-4 years ago.
Now I am getting around to restock on things I am running low on. Some of them the Formulary can't ship internationally. Post 9/11 this is due mainly to the ability to use them for more nefarous purposes than just in a darkroom.
So I may be visiting McGee St in the future.
If you want we can tag up on an order, I am thinking about September.
I do know John and he is great, so is his son, and they do give great prices on bulk.
I am thinking of these chems, and any Canadians wanting to jump on this give me an email.
BW developer scratch
Hypo Clear Scratch
Carbon material Scratch
Sepia toner scratch
Gum printing scratch
basically the gamut, we will be placing an order and could bulk it up if those of you are serious of stocking up a bit.
Originally Posted by Mike Wilde
I am trained as a chemist. The only time I would consider making selenium toner would be when it was no longer available commercially.
I will take that to heart
Originally Posted by Gerald C Koch
I have made up direct selenium toner in the past, with great care, under a fume hood (well, immediately adjacent to the exhaust intake to my HRV that draws at the end of my sink where the fixer tray usually sits) running full blast.
Heating the mixture of the very finely divided Se powder and getting it into a sulfite solution, then heating it, all the whle in nitrile gloves, and wearing a full mouth and nose filtered respirator was a real pain in the ass.
After that first effor I had a few different lots of of KRST come my way. It will be quite a while before I consider mixing selenium from scratch again.