Step-By-Step Guide To Perfect Fillets

Stitch and glue boats have seams. Seams that aren't sealed leak. Leaking boats sink! This is why it is vital to create structurally sound, as well as attractive seals along every seam in your boat. These seals are referred to as fillets.
When it's time to bond the inside corners of your boat, a fillet is generally the way to go. Many newbie boat builders suffer through this process due to lack of proper instruction. This process can require the use of a special tool and a lot of patience. However, you can also make perfect fillets the easy way using ordinary, disposable plastic spoons, wooden tongue depressors, plastic zip-lock bags and masking tape. Let's walk through each step individually so you can grasp what needs to happen and when.
Mixing Epoxy
Several elements will contribute to the dry time of your epoxy. If you're working outside, humidity, temperature and wind can cause your mixture to gel quicker or more slowly than you expect. When you start, it is recommended that you only mix enough epoxy for the first fillet. This will allow you to observe how the epoxy will react and to avoid waste.
You want to mix your epoxy to a consistency that's between mayonnaise and peanut butter. To thicken the epoxy you can use wood flour, Aerosil silica or one of many other products. Aerosil will create an excellent bond, but you should be aware that it will cause your fillets to be harder to fair after the epoxy has cured.
Keeping It Clean
If you tend to be the messy type, you might want to consider using some masking tape around the areas where you'll create fillets. This will help prevent epoxy from getting onto unwanted surfaces and leave you with less to cleanup.
Making the Fillet
Apply thicken epoxy to the corners using a putty knife. Be sure to fill between the frames and the hull to seal every tiny crack - and don't forget the chines. Using a wooden tongue depressor or the back of a plastic spoon, shape the fillets and fair them. Try to keep the same angle in comparison to your corner so you'll have a consistent radius. Remember to clean up any excess epoxy immediately. Dried epoxy is a dreaded chore to clean!
Fiberglass Taping
The most efficient way to apply fiberglass tape is at the same time you create the fillet. The tape should be applied to wet epoxy. However, first-timers may find this method frustrating as it does take some practice. If you're uncomfortable applying fiberglass tape when you make your fillets, let them cure then smooth and fair them with 60-80 grade sandpaper, then apply the tape.
Like everything else in life, practice makes perfect. You may choose to practice your fillet-making skills before you begin on your own boat. That way you can experiment with what works best for you in order to create beautiful and structurally sound fillets that will keep your boat afloat for years to come!