Cap/Diamond Plate Caulk?

[FeatherFam]

Our 2016 Feather 23RBM has a black (aluminum?) trim mold piece that covers the seam where the cap and diamond plate meet. The top is of the molding is sealed with clear caulk, but the bottom of it is not. There is about an 1/8" gap that runs the length of the underside of the this trim piece. I found it by looking straight on and down into the gap between the bed and the cap wall of the interior; I saw a line of light coming into the trailer. Should this gap be sealed? The front end takes on a lot of water.

Also, what about the bottom of the diamond plate? There is a rather large gap between it and the frame. Should this be caulked/sealed?

[abarkl]

Most owners would recommend Dicor's Non Leveling Non Sag Lap Sealant;

https://www.amazon.com/Dicor-Non-Lev.../dp/B004RCSR1G

[BigJohnD]

Black geocel proflex. Matches and best you can buy in my opinion. You won't find too many colors other than white and clear at Rv places, but look online for them and you'll find it. Have used it 13 years I think.

[Seann45]

Leave the bottom open.. it lets any water that manages to get back there drain out, just like your shower stall.