Silicone on glass fabric - no adhesion

Hello everyone,

here is a newbie. I would like to warmly greet all forum members.

I have a small problem. I am looking for a tensile and waterproof fabric on which I can bond something using simple sanitary silicone.

I got some glass silk fabric from a painter, which looks like a sieve fabric. To make sure there are no holes, I also took a piece of painter’s fleece.

To my surprise, I was able to bond the two fabrics perfectly with the sanitary silicone and then the actual fabric on top.

Okay, then I got glass fabric - fiberglass wallpaper from Bauhaus because it is dense and doesn’t have holes like the glass silk fabric. But the silicone does not stick to this glass fabric. I then went to another Bauhaus and got glass fabric from another manufacturer. Same result, it doesn’t stick.

I just wonder why everything sticks on glass silk but not on glass fabric.

Does anyone have an idea if there is an adhesion promoter for this? I have already tried adhesion primer and even adhesion primer for silicone paints. It doesn’t help.

Thank you very much.