From: '''newspam'''@nonad.co.uk   
      
   On 30/11/2025 22:16, Don Y wrote:   
   > Something optically clear, temperature range of -40C to +60C (70C would   
   > better)   
   > that can tolerate daily changes of ~30C for ~20 years.  Ideally,   
   > adherent to a   
   > variety of surfaces but I can compensate, if necessary.   
      
   If it is optically clear it won't stay that way for long under hot UV   
   desert conditions. You can't put enough UV stabiliser in to keep it   
   clear for long. Most materials that tolerate UV have a surface coating.   
      
   Even in the UK clear weatherproof potting compositions on cheap solar   
   cells yellow and deteriorate to crazed opaque surface in a matter of a   
   few years. The expansion and contraction will also be problematic.   
      
   > And, not exhorbitantly priced (I need gallons of it)   
      
   It will have to be exhorbitantly priced. Or opaque absorbing or   
   reflecting UV away will protect the bulk material.   
      
   --   
   Martin Brown   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)