My front bulkhead is in good condition and i want to keep it that way.
I was thinking of putting 4 inch flex tape from one side to the other.
That way no rainwater while driving will find its way in.
Any commenta?
I did something similar with automotive panel bonding adhesive. It worked as intended, but you are only solving one point of vulnerability for water intrusion. If water comes in from the top, now, all you have done is made it even harder for it to be evacuated.
My experience is mostly with the rear bulkhead, but it may be useful.
We had little rust on the bulkhead framework, just surface rust and some minor pitting. The exposed threads of the bolts were mostly gone. If I remember, two or three of the eighteen bolts still had heads connected to the "tails." A previous owner, probably long ago, had sealed the bottom edge of the rear bulkhead joint with caulk.
My theory is that the caulk stopped debris from falling through. The debris got caught and, for long periods, stayed wet. I remember it took a couple of hours with a putty knife to clear the little gap between the bulkhead and frame.
My own opinion is that the best strategy is to keep the channel open, and clean it out periodically. Anything that slows or stops water or debris from getting in, also stops it from getting out.
Stay off of salted roads even in early spring.
Brett Wolfe has a good white paper on here and I think he recommended something like auto undercoating. It may be good to read his writeup and see if maybe you like that idea.