From: peter@tsto.co.uk   
      
   On 30/03/16 16:38, Poutnik wrote:   
   > Dne 30/03/2016 v 17:14 Peter Fairbrother napsal(a):   
   >> I use a 5% solution of KOH (for Brashear silvering) from time to time,   
   >> frequently enough so that I don't want to make it up every time, but not   
   >> so frequently that a bottle gets used up fast.   
   >>   
   >> My problem is what to store it in. Glass is out of the question, as is   
   >> PET. PP maybe, but does CO2 diffuse through it?   
   >>   
   > What time scale to consider.   
      
   Perhaps a year or two?   
      
   > But generally, with PE bottles I would be afraid more   
   > about gas-proof tightness of the opening,   
   > as they are not very precise.   
      
   Agreed, though you can get (expensive!) gas-tight ones. I recently saw a   
   HDPE bottle full of acetone for sale ...   
      
   > And CO2 exchange during manipulation.   
   >   
   > How sensitive is it ?   
      
   Don't think manipulation would be a worry - a little CO2 won't hurt,   
   though a lot would be a problem. Supposed to be 5% KOH, let's say 0.5%   
   K2CO3 maximum.   
      
   I don't _think_ a single-layer PP/PE bottle would work, though I don't   
   actually know.   
      
   PVC?   
      
   Thanks,   
      
   -- Peter Fairbrother   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)