Seam Seal - between caul and fender, Before I paint Options

[ruby914]

It looks like both front fenders were replaced at some time in my cars life.
I can't say they did a bad job but they never replaced the seam seal.
Originally was there a bead of seam seal at the bottom of this gap between the caul and fender? The 3 mm gap narrows to about 1 mm at the bottom. I am thinking I should fill that 1 mm gap. The way it is now water can drip thru in areas. I am not sure if that is a good thing or bad. (IMG:style_emoticons/default/confused24.gif)

[ruby914]

Thanks guys,

I did clean out the channel and epoxy prime with a brush on the passenger side.
The tons of seam seal bottom side was removed by the PO.
Even with out all that seam seal it's hard to imagine how they removed and replaced the fender or how it was constructed at the factory.
I do have the rubber seal and intend to install it after paint. The seam seal I was thinking of top side would not interfere with the rubber seal.
Calling this channel an "Expansion joint" helps my understanding of why it was constructed this way. I recall someone telling me welding / fill it up was not a good Idea for that reason.
My concern is the rubber seal not keeping 100% of the water out after it is installed.
Now there are areas that the water will leak down in front of the door seal near the hinge. Good to keep water out of the seam but I feel its not the original design intent.
Maybe the ton of seam seal fills this from the bottom?
It is next to impossible to take clear photos. I try to show a hole where water would drain thru in this photo. Not sure if this was the original intent.

[SirAndy]

I try to show a hole where water would drain thru in this photo.

That looks like a rust hole ...
(IMG:style_emoticons/default/sad.gif)

[ruby914]

I try to show a hole where water would drain thru in this photo.

That looks like a rust hole ...
(IMG:style_emoticons/default/sad.gif)

See, that's what I have a hard time with. Snooping around in this hard to see spot, it looks like the fender was replaced and the new(er) fender was gnarled in the process.
I don't see thinning as rust would do. Its more like an intentional trim to fit thing, kind of a square edge, some new welds and spot welds rewelded (IMG:style_emoticons/default/confused24.gif). Like someone removed the fender to trim some rust.

So, normally this channel runs into the trunk channel and would be water tight?
With only the fender to cowl and trunk seals keeping water out.
(IMG:style_emoticons/default/idea.gif)