I have Pella windows and sliding doors. One of the sliding doors is starting to "rot". We have curtains on the inside and you never really see as it is in my bedroom. Just a door to let the Schnauzers and Weenie dog out. It's not soft and you cannot push your finger in to damage it. It's still very tough. It is slightly deformed but not bad. It there something you would recommend to help this situation? It has 2 panes of glass and I can remove the inner glass panel. Maybe drench it with some elixer? I don't have the money to replace the door at present or the foreseeable future. Should I use Group II or Full Synthetic? Just pour and let is soak it's way down? Oh, Pella did confess to this being a problem but I am out of warranty as these doors were installed in 1994.