The Choprical Fish: a Human Powered Party Bike

Step 12 Mate subwoofer retrorockets with side panels.

I hollowed out the foam inside the retrorockets with various picks and brushes.

Next I positioned it properly in the plane of the side panel, then tacked it in place with some 5 minute epoxy. Once it was tacked I created a very strong epoxy fillet on both sides of the side panel.

In order to create epoxy fillets you have to have an understanding of epoxy thickeners. If you don't use thickeners, the epoxy will run down your form like maple syrup. I used two thickeners on this project: cabosil and microspheres. Both are very lightweight powders. Cabosil is the better of the two for thickening epoxy to the consistency of vaseline or smooth peanut butter, while microspheres are better if you want more of a lightweight paste. They can also be used in combination, but I am still an intermediate/beginner at this and can't offer any rules of thumb.

In any case, I wanted a nice, glossy fillet was translucent, so I used cabosil to thicken the resin. I applied packing tape to my side panels beyond the glue line, to avoid smears.