[alt-photo] Re: NuArc 26-1KS ideal vacuum pressure?

[david drake]

I had to replace the vacuum glass on my unit. My original glass was  
5mm thick and 25 x 30 inches (slightly wider than the unit). It's just  
regular glass.

david

On 6-Apr-10, at 10:08 AM, francis schanberger wrote:

> When I bought my NuArk 26-1K a few years back, the vacuum glass  
> didn't make
> it intact during shipping. Eventually I hope to replace it. Would  
> anyone
> using this model be kind enough to measure the glass dimensions  
> including
> thickness? What type of glass should I purchase to replace it?  
> Tempered?
>
> At the moment I am content using split back frames including my new  
> 16 x 20
> frame from Bostick and Sullivan with the rounded corners. The double  
> hinges
> allow me to print two separate negetives with different exposure  
> times,
> simultaneously without losing registration.
>
> -francis
>
> On Tue, Apr 6, 2010 at 9:23 AM, Jeremy Moore  
> <jeremydmoore at gmail.com> wrote:
>
>> I use ~9, but that's assuming my dial is accurate. Any higher than  
>> this
>> setting and I don't get any increase in sharpness so I've just left  
>> it
>> there. You should also be sure your emulsified paper/negative combo  
>> is
>> backed by something to help keep the moisture from being sucked out.
>>
>> -jeremy-
>>
>> On Tue, Apr 6, 2010 at 3:08 AM, Loris Medici <mail at loris.medici.name>
>> wrote:
>>
>>> Hi all.
>>>
>>> Yesterday, I finally managed to have my new NuArc 26-1KS installed.
>> Pretty
>>> exiting, seeing the vacuum bed operate was a real eye opener; I will
>>> finally
>>> be able to make sharp prints sized 12x12" / 11x16.5" or 12x16".  
>>> Plus, the
>>> light integrator is a real bliss.
>>>
>>> My question is, what is the ideal vacuum pressure for the following
>>> processes? (If the concept isn't a total nonsense, that is...)
>>>
>>> - Iron / iron-silver processes: Cyanotype, Vandyke / Argyrotype and
>>> Pt/pd...
>>> - Dichromated colloid processes: Gum Dichromate, Casein and  
>>> Carbon...
>>>
>>> As we all already know, humidity level and/or maintaining an  
>>> absolute
>>> minimum of humidity in the paper/emulsion is essential for making  
>>> those
>>> processes work successfully. Therefore, I fear of using too much  
>>> vacuum
>> and
>>> to cause humidity escape from the paper/emulsion.
>>>
>>> I'm thinking something around 10 mmHg... ???
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>
>
>
> -- 
> francis schanberger
>
> www.frangst.com
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>

david drake photography
www.daviddrakephotography.com