Spare tire drains - shape and closed with a bolt

[Dave Whittick]

Couple of questions while I’m cleaning and prepping my under carriage for epoxy and undercoat.
1) Is there a conical shape in the metal in front of the drain or is the bottom simply flat with a hole?
2) There was a nut and bolt through the drain with a brass washer. Is that supposed to be there?

[Brad Ripley]

That is the factory drain hole in the battery floor pan -- probably contributed to many a rusty pan! Your previous owner obviously tried to plug it with a bolt, in the process made to hole larger. The pieced hole was supposed to be shaped like a miniature louver, made with a die like illustration below. If you are preparing your car for "concourse" that would be one thing but instead, you may want glue a small cover on the inside to prevent moisture from entering and to give a better presentation than just a bolt.

[Mike Wilson]

I use body dum dum to seal the holes in mine.

Mike