Skywriter
Well-Known Member
A four-fin rocket needs sixteen internal fillets. That’s a lot of fillets, and none of them will be easy. All of them will be messy. What can you do? Go buy some skinny (depending on the size of your rocket) wooden dowels and a ¼-inch dowel. Cut the dowels into lengths that are about six inches longer than your fin base. Get yourself setup with some thick epoxy, e.g., RocketPoxy, and stand your rocket upside down. Spread out a line of the epoxy on a flat piece of wood or cardboard and roll a skinny dowel in the epoxy. Quickly transfer the dowel into the bowels of the engine department, sliding it down along one of the joints and keeping it tight against the juncture. Pull it up an inch, cut it flush, and push it back down. Insert the ¼-inch dowel and press it against the skinny dowel to be sure it is in tight. Repeat for the rest of the fins. You might be able to do all the internal fillets with one big batch of RocketPoxy in less than 30 minutes without a giant mess. I’ve done this several times and it actually seems to be stronger than just dabbing in those fillets, but I wouldn’t use this for the external fillets just because it would look weird.