PVC cement - compatible w/ silicone sealant?

[Giantsean]

I can probably guess the answer already, but just in case. If I have a PVC fitting which is attached with silicone sealant, and I want to bond them instead, do I need to have completely bare plastic? From my experience very few things stick to cured silicone (sometimes including more silicone and I'm assuming PVC cement may be no different - and that a good cleaning is in order (of course, it's in a hard to get to place... of course )

Thx!

 

[Jadnashua]

PVC cement works by melting the plastic, then when the solvents evaporate, it becomes welded together. So, anything that would prevent the cement from coming into contact with the plastic would prevent the joint from being made.

 

[Sponsor]

 

[Gary Swart]

PVC "cement" or "glue" is neither. It is a solvent that melt the outer surface of the PVC and when the pipe and fitting are slid together, these two melted surfaces blend together and form a welded joint. Much the same as welding metal except this is done chemically rather than by heat. We all tend to call the solvent cement or glue and that confuses lots of people.

 

[Dj2]

PVC fittings and pipes have to be cleaned before cemented, that's why we prime them. Silicone will be a spoiler.