406 Colloidal silica is the general-purpose thickener, for when you don't want the epoxy to run. I also use the 407 additive which makes the epoxy easier to sand. It's good to have both around.
However, when filling through-deck penetrations, I usually put masking tape over the bottom of the hole, and pour un-thickened epoxy in. This gives the best penetration into the core. When that is set, it will be concave, and I then add some epoxy thickened with 406 to finish.
As I found out, this doesn't work if you have a liner inside the salon roof - the epoxy runs down the gap between the liner and deck. Then it has to be all thickened.
On the West System website there is a guide to selection of hardener, which is essentially according to temperature. I tend to use 206 for the deck as it sets quicker and I don't need the last word in strength.
However, when filling through-deck penetrations, I usually put masking tape over the bottom of the hole, and pour un-thickened epoxy in. This gives the best penetration into the core. When that is set, it will be concave, and I then add some epoxy thickened with 406 to finish.
As I found out, this doesn't work if you have a liner inside the salon roof - the epoxy runs down the gap between the liner and deck. Then it has to be all thickened.
On the West System website there is a guide to selection of hardener, which is essentially according to temperature. I tend to use 206 for the deck as it sets quicker and I don't need the last word in strength.
