i used the blue RTV. got a big caulking size tube of it from Amazon.

 

What is that piece you bought at Lowe's to connect them normally intended for? Also, does anyone have one of these that runs them through a car wash? Just curious if they will survive a automatic car wash brushes and if you take the top off and tape is up to seal it when you go through the wash. I know with the rack in this case, that is a no go, but wondering if they can handle it and not come apart?

 

looks good

 

It's called a Fernco, any hardware store will know exactly what it is, it's a connector for PVC, I think. Perfect diameter