| Anne, are you clearing in a bath of water or running water? Generally, a combination of three separate baths of water with a pinch of citric acid in each, works well. Also, if the paper is not soaking up the sensitizer it will easily come off in your rinse. Most find that VDB and other iron based processes require a higher humidity than normal (60% ) is important for good results. the humidity helps the paper absorb the sensitizer, otherwise it stays on the surface. this is a bigger a problem during winter or in dryer climates. Francis, what is sprint fixer remover? Is that a hypo wash or sodium sulphite? I also do double coating to get good dmax. this can also be problematic during the clearing stage it takes much longer to clear. Toning in platinum, palladium or gold is also recommended for permanence and very nice blacks.
david
On 10-Mar-09, at 1:13 PM, francis schanberger wrote: I suspect the water supply pH or minerals may be involved. I am having slight changes to my VDBs depending on where I process them. At school they seem to dry down a lot more and give me a very strong brown background compared to the ones I make at home.
You may also wish to experiment with shorter fix times or changing your dilution of thiosulfate. I am using a 30g per liter solution.
I don't clear with citric acid but with Sprint Fixer remover.
-francis
On Tue, Mar 10, 2009 at 12:53 PM, Anne van Leeuwen & Peter Hoffman <anne_peter@earthlink.net> wrote: Hello, I've recently been using VDB again but with different results than I've had in the past. I made up a fresh batch of the VD and am using fresh thiosulphate, the results are not a strong brown and there is weak contrast. When I first rinsed the contrast was good but that was quickly lost. I did try pot. dichromate but that didn't do anything visible to the contrast. Any suggestions would be appreciated. Thank you. Anne
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francis schanberger
www.frangst.com
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