I'm making my first rod.... it's a one piece ML popping rod for bass.... I read somewhere that water inside a blank can be bad... probably bunk, but what do I know?! I would think the inside of the blank would be as water proof as the outside? Do I need to plug both ends of the balnk before I finish?

Your tip top should plug the tip section , and your grip with either butt cap or cork plug will plug the butt section... should not have a problem..

With regards to the "water in the blank" I know of ice fisherman that have dipped their poles into the hole and thus into the water... and after a bit of fishing, the water in the tip section froze and the tip broke... but other than that I do not know of any problems with water getting into the blank..

Note: some of the tip tops that I have used, are in deed open at the hoop of the top itself, in other words, the tube is open right at the tip so water could get into the blank if you use one of those tip tops...

I am sure others will offer their assistance as the day goes on.

Tight lines,

Art

If you are worried about it put a little Rod Bond or silicone caulking in the openings.