bczoom,</P>
Maybe your doing it to cheap !!! Spend that money !!!</P>
The only silicon sealant to use on anything is GE Clear ~~~~ I have tried just about all brands, and the only one that I have found that would work on just about everything is GE !!! Cost a little more but it's worth it. DONT BUY THE WHITE OR ANY OTHER COLOR or Brands. ( Please dont even think about Red Devil Brand, talking about a joke ) Something about the pigments / properties in the stuff doesn't let it "grab" & "hold" as good and will notstand up to what is suppose to. I have gone to Sign Industry Shows, all over the states, and they preach this ..... But be sure to clean whatever you are installing it on with alcohol , that strips all of the propertys off the substrate and will make it work just perfect. 3M CLEAR is also a great product, we use this everyday in the sign industry, and found that the GE Clear is a excellent product. Purchase them in the tubes that goes into the caulking guns .</P>
Give it a try, it will work ~~~~~ Or, you can go purchase some "SEAMLESS GUTTERS" </P>