[Alt-photo] Re: Sulfamic Acid for Paper Acidification

[Serdar Bilici]

Hi Loris,

I agree that there might be a sweet spot for dmax with HCl, but really why fiddle :)  Sulfamic acid has a great advantage at storage, it is not as corrosive as HCl to metals, so it is safer to work indoors, the prints have better dmax in comparison.

(You already know this bit, but I should include it for other readers) 
When I made a research about sulfamic acid and its uses, I have found out that sulfamic acid is used in modern descaling systems to remove calcium deposits instead of HCl. Due it is less corrosive but it has equally strong acidic nature. As you said, probably sulfamic acid leaves the paper in better condition compared to HCl due to its less corrosive nature.

In terms of dmax, HCl treatment gave me the poorest results among the acids I have tested. Although, it was the right choice theoratically, (being a mono-acid, highly water soluble byproduct, fast reaction, good capacity) practically the results were not so appealing. Considering that the fumes of HCl would corrode the metals in the room it is used in time, I understand why it is not the most popular choice to acidfy papers. Proper ventilation is quite important when working with HCl (Dangerous chlorine gas release), on the other hand Sulfamic Acid + Calcium carbonate reaction produces only CO2 gas.

Compared to HCl it is a WIN-WIN.

Regards,
Serdar

-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org [mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of Loris Medici
Sent: 05 Mayıs 2013 Pazar 11:18
To: The alternative photographic processes mailing list
Subject: [Alt-photo] Re: Sulfamic Acid for Paper Acidification

Hi Alberto & Serdar,

To me it works better than HCl for Fabriano Artistico TW HP and EW SP side by side. (Better tonal range and less grain, much more smoother results.
siightly better Dmax - perhaps sulfamic acid leaves the paper in better physical condition than HCl,???) Maybe I could try different dilutions and/or treatment times with HCl, in order to find the sweet spot that works equally well (if there's one) but why fiddling? Sulfamic acid is much easier to deal with and the stability and capacity of the solution is very good.

Regards,
Loris.


2013/5/5 Serdar Bilici <sbilici at gmail.com>
>
> Hi Alberto,
>
> Unfortunately, I haven't prepared samples to compare.I started testing
with
> HCl then oxalic acid then briefly tested citric acid. I even tried
tartaric
> acid for fun (it works).
> As I have mentioned in the post, the problems I had with other acids
forced
> me to look for an alternative in the first place.
>
> I did not want to start a 'which acid is better' argument so I did not 
> include the problems I observed with the other acids in the forum 
> post. I still try not to mention the problems. :) I thinks the samples 
> and the advantages of sulfamic acid are fine enough,
If
> people are convinced they would give it a shot IMO.
>
> P.S. I haven't tested vinegar/acetic acid on purpose. Vinegar has
additives
> different brands have different concentrations.
> Concentrated acetic acid fumes is bad for lungs, considering that the 
> acidification procedure would take considerable time I did not want 
> that kind of exposure due to my asthma.
>
> Regards
> Serdar
>
> -----Original Message-----
> From: alt-photo-process-list-bounces at lists.altphotolist.org
> [mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On 
> Behalf
Of
> Alberto Novo
> Sent: 05 Mayıs 2013 Pazar 09:21
> To: alt-photo-process-list at lists.altphotolist.org
> Subject: [Alt-photo] Re: Sulfamic Acid for Paper Acidification
>
>>> I would be pleased to hear your opinions, suggestions for optimizing 
>>> the procedure.
>>> I did some test using new cyanotype, argyrotype and Loris did some 
>>> testing with ziatype and argyrotype.
>>
>> Sedar, did you compared (by means of step tablet printing) the 
>> sulfamic
acid
>> treatment vs other acidifying methods , e.g. HCl, citric acid, etc?
>>
>> Alberto
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