CAULKING

Originally posted by GLBCamper Originally posted by David UPDATE...It looks like it they have changed the name (says original formula) Polyseamseal Which exact product do you use on exterior windows? The link goes to all of loctite sealants.

Good question! The last time that I bought some, it was still labeled "Polyseamseal" All Purpose. If I were buying today, I would likely purchase the "Premium". I use it on window frame to gel coat. I also use it around the side marker lights, porch light, etc. I don't have anything negative to say about the stuff. It seems to have good adhesion, resists mildew, remains somewhat flexible and is easy to work with. Clean up with soap & water.

In theory, there is a rubber gasket sealing the window frame to gel coat mating surfaces. However, I like to take the "belt and suspenders" approach and keep a thin bead of caulk around them.

I would not recommend using a silicone. When I have used silicone where I use to work you have to do a lot of surface preparation and priming to make it work correctly. When I did marine electronics repair I stayed away from silicone because most of manufactures say not to be used below the water line of your boat and it can also corrode electrical connections if you use the wrong one. I inspect every seam once a year and touch up where I think it needs it. I have tried different sealants and right now my favorites are Dicor Lap Sealant Self Leveling #501LSW and the Non-Leveling Non-Sag #551LSW. A couple of months ago I replaced my TV antenna with a new one I used the Self leveling sealant for the first time and I was very impressed with how well it leveled out. I am not sure what type of sealant the Dicor Lap Sealant is. I looked at their MSDS and think it might be a Butyl, solvent based sealant. There are 7 types of sealant Latex, Acrylic, Butyl, Polysulfide, Silicone, Polyurethane and MS Polymers (Modified Silicon).
Here is a very good article from Good Old Boat about the 3 different types of sealants, Silicone, Polysulfides, Polyurethanes
Suffering from sealant confusion? (marine)
http://www.goodoldboat.com/reader_services/articles/sealant.php

How to Choose a Sealant That Works (Buildings)
http://www2.buildinggreen.com/blogs/how-choose-sealant-works

UPDATE...It looks like it they have changed the name (says original formula)

Polyseamseal

So far, the only spot that has needed recaulking was over the back window. Just cleaned the old off, put down new. I have redone the Lap sealant at the top of the spoiler, and around one of the sewer vents.

I inspect our each season and only re-caulk if it needs it or if a leak springs up