The stuff I use on my glasses is designed for aircraft cockpits, Repcon, and is friendly with plastics and perspex, soon as droplets of water hit the glasses it just bounces off or runs away to the side on impact. The sad thing is they do not make it any more as it was banned for safety reasons as repellants do mar the clarity on windscreens but luckily I aquired a half litre bottle from work for use on my car windscreen, over 30mph and there is no need for wipers, but on your bike it works at even slower speeds and should last me years if I only use it on my cycling glasses. Simonz paste wax is recommended as a replacement as I have just found out by googling it.
As for waterproofing materials, for my small underseat saddle bags I use Thompsons water seal. I also use it on my bivvies for fishing too and water just runs off, but it does darken the fabric and also makes it stiffer. Thompsons do two different types, but the one that is OK to use is the one that lists fabrics etc in the instruction, It's in the red and white tin and is far cheaper than fabsil etc
As for waterproofing materials, for my small underseat saddle bags I use Thompsons water seal. I also use it on my bivvies for fishing too and water just runs off, but it does darken the fabric and also makes it stiffer. Thompsons do two different types, but the one that is OK to use is the one that lists fabrics etc in the instruction, It's in the red and white tin and is far cheaper than fabsil etc
