Re: Beer coating

[Loris Medici <mail@loris.medici.name>]

I (think I) figured out what my problem was: It's very short drying time
before water bath. I should have waited more (maybe overnight)... I
concluded this by the fact that eventually, the vessel I mixed the beer
coating wasn't rinsed enough, and few days later I noticed a milky white /
hard residue (precipitated silica?) which won't come off without scraping.
(Brutal usage of Scotch Brite and few drops of detergent does the job
BTW...)

Will try again, waiting overnight before rinsing the sheet (and then size)...

Regards,
Loris.


31 Mart 2009, Salı, 1:13 am tarihinde, henk thijs yazmış:
> Dear Loris,
> Just be back in one week .. hope i can help you then,
> Cheers, Henk
>
> On 30 mrt 2009, at 22:58, Loris Medici wrote:
>
>> Dear Henk,
>>
>> I tried beer coating tonight on a thoroughly cleaned and dried plain
>> aluminum sheet. Unfortunately the coating washed away in the cold
>> water
>> bath. What could I have done wrong?
>>
>> 1.  I opened a can of Pilsener and let it sit in the fridge for 24h
>> 2.  I took 100ml of the can and waited to normalize to room
>> temperature (21C)
>> 3.  I mixed 1g of caustic soda (NaOH) into the beer
>> 4.  I mixed 10ml of sodium silicate into the beer
>> 5.  I stirred thoroughly
>> 6.  I immediately brushed the mixture onto a clean sheet of
>> aluminum using a
>>     foam brush
>> 7.  I dried using a hair dryer in the middle setting
>> 8.  For the sake of getting an even primer coating, I coated the
>> sheet once
>>     more with the primer
>> 9.  Same as 7
>> 10. I washed the sheet gently rocking a tray
>>
>> The coating dissolved and left the sheet during step 10. BTW, FWIW,
>> when
>> you put the sheet into water you can hear a fizzing sound (but
>> can't see
>> any bubbles)...
>>
>> ???
>>
>> Thanks in advance,
>> Loris.
>>
>> P.S. I couldn't manage to coat the Forex sheet with beer + silicate.
>>
>> P.S.2. If I can't make it work, will try to put plain acrylic gesso
>> (which
>> doesn't hold gum by itself) on the sheet, sand and then coat it
>> with beer
>> + silicate
>>
>> P.S.3. I prefer to be able to coat the sheet w/o any acrylic gesso
>> since I
>> plan to buy white painted (enameled?) aluminum sheets later -> I
>> just want
>> to skip the whitening step for relatively conventional photographic
>> prints...