Glycerine stick
A professional restorer knows better than anyone else that rubber parts should never be assembled with grease, multi-spray, soapy water or any other agent. Use only glycerin for this purpose.
If a lubricant is needed, make sure it consists mainly of glycerin. When using agents without glycerine, there is a high chance that the rubber will be damaged and ageing will be accelerated. There are many examples of windshield rubbers that within one year already have dry cracks in the corners because the wrong lubricant was used during assembly.
As stated for many rubber parts, the warranty is even excluded if it cannot be proven that glycerine was used during assembly. You can prove this by producing an invoice that shows not only the rubber part but also the glycerine.
The glycerine stick mentioned here is not only intended as a lubricant, but also for the maintenance of rubber parts and to prevent sticking and freezing of door, engine and boot lid rubbers.
A glycerine stick should be part of your toolbox and should always be available, if not to mount rubber parts, at least to take care of them.
