Sealing Jamb?

Looking at pictures showing the breakdown of standard window parts, I think I have the term right. What I want to know is how to properly seal the spot at the bottom where the jamb meets the sill. There is a small slit where the vertical jamb and the horizontal sill meet and I want to be sure that any water in the sill cannot seep into those spots and into the wall cavity. I have caulked those corners on either side, but the caulk gets quite dirty and when opening the window a bunch, the caulk can come loose. Rather than go through and pull out that caulk every year and re-do it, I wanted to get some opinions as to whether there might be a more permanent solution that wouldn't require me to redo that every year.

I'm envisioning something like a solder that can seal the metal slit permanently, would be black or dark in color so it wouldn't show dirt and could be precisely painted on or something so that it could be easily applied and not make a mess. In that way it would be sealed, I could just wipe the inside of the window sill each year and make sure nothing is blocking the majority of the water from getting out of the sill through the exterior facing sill openings and be good to go for another year.

Does that make sense? I attached two pictures to try and make it a bit more clear. Thanks ahead of time for any info/suggestions.

For one thing you've used way to much caulking.
New calking will not stay stuck to old so every bit of it's got to come off.
If those are vinyl replacement windows then there was no need for caulking, the seams are ultrasonic welded in the outside corners on the outside of the windows so all your seeing is a seam on the inside were the two pieces come together. By apply caulking you have sealed up the channel where water runs out of the tracks allowing water to build up in the tracks along with all the dirt.
If you insist on caulking it any way clean it all off and use 100% silicone and this time only put a tiny amount, just enought to fill the tiny seam. It does no good to have it blobed all over the vinyl where it's flat.

joecaption said:

For one thing you've used way to much caulking.
New calking will not stay stuck to old so every bit of it's got to come off.
If those are vinyl replacement windows then there was no need for caulking, the seams are ultrasonic welded in the outside corners on the outside of the windows so all your seeing is a seam on the inside were the two pieces come together. By apply caulking you have sealed up the channel where water runs out of the tracks allowing water to build up in the tracks along with all the dirt.
If you insist on caulking it any way clean it all off and use 100% silicone and this time only put a tiny amount, just enought to fill the tiny seam. It does no good to have it blobed all over the vinyl where it's flat.

Click to expand...

Thanks. They aren't vinyl replacements, I believe they are aluminum. They're whatever was cheapest for the builder to install in 2002 in Florida when the house was built. We're the 2nd owner, so I don't know for sure. To get the caulk to stay in place I was having to put my finger in there to press it down and into the seam, which was not easy in that tiny space. It wasn't staying in place otherwise. Is there any particular brand of 100% silicone caulk that works better than another? Since that area is so small, I can't get the tip of the caulk in there to follow the small slit all the way around, so I'm thinking I'll use a very small hard tip brush and see if that works out better, removing all the old stuff first. Thanks again.