viradon, take 3greenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
okay, so i've largely solved the milky-viradon-scum problem by using distilled water. i've also been dunking prints in an HCA solution (heico permawash, 4 ounces:1 gallon) as per someone's suggestion for avoiding post-toning. i'm still getting post-toning, i swear. should i be using a stronger mix of the HCA?
also, is buying jugs of distilled water at the grocery the best way to get it? would a brita or pur water filter supply a similar enough cleaned-out water, or do i need water that has actually been *distilled*?
best, brad daly
-- brad daly (firstname.lastname@example.org), August 05, 2000
Most of these filters take out all you need to take out of the water for photography. You are using way too much Perma Wash. And do you also use a photoflow? You may be using too much. James
-- james (email@example.com), August 05, 2000.
I'm curious about the milkyness problem with Viradon. I ran into this problem with Kodak brown toner. I believe the problem resulted from straining the solution from one jug to another outside during cold weather. I think I inadvertently allowed the mixture to become aerated, thus causing a reaction. I've never done this since and have not encountered the problem. I might add that I have also stopped adding hypo clearing agent to my toners. I have found that the odor of the brown toner is not near so severe by eliminating the clearing agent. Once my prints are removed from the toner, I place them in a tray of Kodak hypo clearing agent for about ten minutes. This allows the toner to clear so I can judge the results.
-- Tom Schumacher (firstname.lastname@example.org), August 05, 2000.
"too much permawash"? please explain. the bottle instructs 3 ounces:1 gallon. i used an extra ounce 1) because it's easy to measure out a half a cup (4 oz) with the jug in which i mix it, and 2) i was hoping it would stop toning more quickly.
as for the reply about the milkiness problem--sorry, i can't remember the name of the poster--i think it's definitely a problem of oxidatation or reaction with *something* in the air. i tested this by toning a print and then propping it against the side of the tray, with one half exposed and one half under the toning liquid. the exposed side was *covered* with the white scum. using distilled water *and* cutting the concentration from 1:50 to 1/2:64 (that is, a gallon jug of distilled water) cuts it considerably. it also slows down toning.
best, brad daly
-- brad daly (email@example.com), August 05, 2000.
Most of the filter type devices only remove some chemicals. Most do not remove minerals. And typically dissolved minerals produce scum.
Sears sells a table top distiller. I bought mine on sale for $80. It does 1 gallon of distilled water in about 5-6 hours. I got a 10 gallon tank with spigot and store it in there for use.
You can also install a reverse osmosis system. This will remove minerals and chemicals from the water. They run from a little over $100 on up depending on source and capacity.
-- Terry Carraway (TCarraway@compuserve.com), August 06, 2000.
Most of the "distilled" water bought at drugstores is actually rather demineralised (by using an ion exchanger) than distilled. As has been pointed out in a previous post, however, that's more than fine. Although most darkroom chemicals are formulated to be used with tap water excessive hardness (i.e. calcium and magnesium content) sometimes causes problems. AFAIK, the cartridges of Brita and other filters contain an ion-exchanging resin to catch some of the minerals and activated carbon for a few other contaminants. Sometimes there may even be trace amounts of silver in the carbon to act as a preservative via the oligodynamic effect. The performance of such cartridges degrades exponentially, which means they are highly effective for the first few litres after which the effect falls off dramatically. Thus, most of the time, the effect is less than half the initial performance. If you wish consistent quality, buying demineralised water from the drugstore may be the better idea. Petrol stations may also sell (or even give) you some as they use it for the car batteries, but there the quality may depend on how carefully the owner regenerates his ion exchanger or revers-osmosis equipment.
-- Thomas Wollstein (firstname.lastname@example.org), August 07, 2000.
After some thorough experimenting with Viradon this is what I have found:
Go straight from the fixer to the toner. Do not wash in between or you will get splotchy prints.
Use the Viradon at the recommended strength, not weaker.
Pull the print from Viradon and go directly to a 10% solution of Sodium Sulfite. Agitate immediately and for a few minutes, then wash. I had no luck avoiding post toning any other way.
My viradon turns milky too, but I ignore it and it doesn't seem to cause problems.
-- Erik Ryberg (email@example.com), August 17, 2000.