silicone sealant problems

[Tom272]

Hi

I need to use sealant between white PVC and black rubber, outside. I think I've been using the wrong stuff!

I have been trying to use standard white bathroom sealant and it has not been setting properly and becomes yellow in about 24 hours. I think the rubber may be the problem, should i be using different sealant? or something else entirely?
Thanks

 

[wingcoax]

I presume you have a leak on your double glazing. Try frameseal, it is rated for outside use.