U of S | Mailing List Archive | alt-photo-process-l | Re: Preparing Al sheets; other factors

Re: Preparing Al sheets; other factors

Ok found something about the first question; NaOH is necessary to adjust
pH of beer so no silica gel precipitation occurs... My understanding is
that after washing the primed sheet, you loose NaOH and pH becomes acidic
again, therefore a very porous silica gel layer forms on the surface. The
porosity provides the tooth, also the proteins from beer are useful to
help the gelatin and gum coatings cling to the surface later... Do I get
it right?

Very neat/bright idea! :)


25 Mart 2009, Çarşamba, 2:40 pm tarihinde, Loris Medici yazmış:
> I asked to my chemicals supplier about waterglass; they have liquid form
> (something around 20-30%)... Is the addition of NaOH strictly necessary?
> Waterglass is already alkaline in solution. What's the purpose of adding
> NaOH? Another question is about beer; with "weak beer", do you mean "low
> alcohol content" or "clear/pale" (or both)?
> Thanks again,
> Loris.
> 25 Mart 2009, Çarşamba, 12:45 pm tarihinde, Loris Medici yazmış:
>> Interesting... What is the color of the coating (first formula)?
>> If it's white then I can just use this with a sizing layer on top, to
>> print gum on aluminum sheets or sealed wood panels. Thanks much!
>> What was the liquid strength of Sodium Silicate you were using back
>> then?
>> (Asking because probably I won't find this in liquid form, only powder
>> or
>> crystals...)
>> Regards,
>> Loris.
>> 25 Mart 2009, Çarşamba, 12:03 pm tarihinde, henk thijs yazmış:
>>> Loris,
>>> Forgot to mention that the article can also be found on:
>>> http://www.alternativephotography.com/articles/art053.html
>>> succes,
>>> Henk
>>> On 24 mrt 2009, at 22:52, Loris Medici wrote:
>>>> Thanks Henk, will look at PF#9...
>>>> 24 Mart 2009, Salı, 6:11 pm tarihinde, henk thijs yazmı�:
>>>>> Hi Loris et al,
>>>>> Just a question:
>>>>> did someone tried the 'old' method with the beer recipe?
>>>>> I did when working with liquid light (SE2) to make bromoil prints on
>>>>> aluminium, see PF#9.
>>>>> cheers,
>>>>> Henk