I had a batch of collodion which was more than 6 months old.
Adding a bit of aceton (2ml at 100ml mix) cleared the collodion mix within 5 days. I assume the process hasen't stopped yet, so it might become a little clearer.
I did the test. I taped a plate and flowed the plate at the same time with 2 bottles. Not easy i can tell you (LOL).
As i had no model (My wife doesn't want to be photographed on Colldion...) i had to take some "dummies"
The left side of the picture is with "renewed" collodion'.
I have used 2 x 4 x 24 watt CLF bulbs. At each side 4 bulbs to get equal lighting.
Exposuretime was 6 secs which is just a little bit more as when i use a fresh collodion mix.
Developing time about 15secs. And ofcourse developed in one flow.
Well, as you can see the result is amazing !!
UPDATE !! : Another update ( not so good....)
I just varnished the plate ( at least i tried to do) with sandarac.
The aceton must have weaken the collodion as the varnish dissolves the picture in a rapid way.
I have never had this problem before...
The part with the old colldodion does not have this problem.
So this might not bring what we are looking for.