Filling gap between bottom rails and ali sides?

[skov]

Afternoon All,

I've got a bit of a gap between my ali side panels and bottom chassis rails in the engine bay. It's been slowly filling with swarf and crap, and I'm a little worried it's going to end up full of water when I get it on the road:



I've just given it a quick clean out, and wondering if I should fill it with some kind of sealant, or possibly drill some drain holes in it.
Any thoughts?