The following is a list of clearing baths, starting at the lowest strength and moving up to the strongest. The list was supplied by Sandy King and was found either here on the alt-photo list server or APUG (I don't recall where) 1. Citric Acid (50g) -
1000ml H20 2. Sodium Sulfite (50g) -
1000ml H20 3. EDTA (30g) -
1000ml H20 4. Heico Perma Wash (4oz)
+ EDTA (30g) - 1000ml H20 5. EDTA (70g) +
Sodium Sulfate (70g) - 1000ml H20 6. Potassium
Metabisulfate (50g) + Sodium Sulfate (50g) - 1000ml H20 7.
Hydrochloric Acid (5% Solution) Extreme care must be
taken when using Hydrochloric Acid
According to this list, Sprint Fixer containing Sodium Metabisuphate (a combination of potassium metabisulphate and sodium sulfate?) seems a little strong for Vandykes. I find even plain EDTA is noticeably harsher on a print.
-david
On 11-Mar-09, at 4:32 PM, francis schanberger wrote: I do have tons of citric acid from doing Ware Method cyanotype. This weekend I will run a test of a citric acid clearing bath vs. the Sprint Fixer remover. It was more of a practical decision. My school has plenty of SFR so I got in the habit of using it as a wash aid more than finding a specific clearing bath for getting rid of iron salts. Sort of a habit developed from cyanotypes hoping the ferric ammonium citrate would clear out as it did when printing blue.
No staining yet. I doubt I have a VDB older than 4 years at the moment to look for signs of insufficient clearing.
-francis
On Wed, Mar 11, 2009 at 11:11 AM, Paul Viapiano <viapiano@pacbell.net> wrote: Francis... You mention 30g per liter of thiosulfate...that's 3%. I was working with even greater dilutions, around 1-2%...as mentioned in some books. Also interesting is the Sprint you mention. I always thought that the clearing bath should be acidic...? Paul ----- Original Message ----- Sent: Wednesday, March 11, 2009 8:53 AM Subject: Re: VDB
David, Sprint fixer remover is a hypo wash(ing aid). It contains sodium sulfite and sodium metabisulfite as well as a chelating agent, not EDTA but Diethylenetriaminepentaacetic acid or DPTA. It is weakly alkaline in solution , pH7.9, but hasn't effected the density of my VDBs. I first got the idea to use this as a washing aid for van dykes after reading Sarah Van Keuren's Alternative Processes Manual in the late 1990's. It also has a bit of antifreeze in it as well. -francis On Wed, Mar 11, 2009 at 10:04 AM, Paul Viapiano <viapiano@pacbell.net> wrote: Anne and David... Wow...no kidding! Every time I do an argyrotype (Ware's VDB cousin), put it in the clearing tray, it looks good for a few seconds and then fades quickly...poof! I think even the James book mentions folks who clear for 20 seconds only. Anyway I started with argyrotype as a less expensive way to get introduced to alt process on the road to pt/pd, and all I can say is that pt/pd is infinitely "easier" to handle... Between argy's clearing and it's ridiculous finicky paper choices, I'll take pt/pd any day of the week! (OK, got that off my chest early in the morning) ;-) Paul ----- Original Message ----- Sent: Wednesday, March 11, 2009 5:45 AM Subject: Re: VDB
David, Previously I was living in Tennessee with very high humidity. Now it's winter time in Michigan --- could be part of the problem. And I have been rinsing under running water. I've been treating VDB like cyan. VDB is so much more sensitive. Thanks for you help! Anne
On Mar 10, 2009, at 9:18 PM, david drake wrote: 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
-- francis schanberger www.frangst.com
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francis schanberger
www.frangst.com
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