Re: Chrome Alum Gelatin hardener

By the way, one should add hardener little by little, with very good
agitation. If you add too much hardener at a time, gelatin clots may
form. In the worst case, if you add way too much, the whole gelatin
solution makes stiff jelly, which you need to use a knife and a metal
scraper to remove the bulk of it and use abrasive cleaning tools to
remove much of the rest, and strong acid solution to totally clean the
residue, because glutaraldehyde hardened gelatin is very stable. (If
the gelatin content is less than 3 per cent of the water, this is less
likely to occur.) Especially if you use expensive coating tool, be
careful not to apply hardener while the tool is immersed in the
gelatin solution. In my very first try of using glutaraldehyde, I
ended up with stiff jelly with foam brush embedded in it. When I tried
to pull the foam brush, the foam got teard off, not the jelly. Now I
use much less quantity of glutaraldehyde, and add it very slowly and
there's no more trouble.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)