I did the Internal fillets very carefully and just one at a time. This gives me ample opportunity to identify issues and make improvements to my procedures.
Drying time
As a result of the , I had to do 12 fillets. Each fillet requires approx 12 hrs to cure. I could probably have got away with 6 hours, but decided against that because I wanted to ensure I get the best adhesion with the fin and motor-mount. Most of the time I just did one fillet in a day, sometimes I managed to do a second one.
Preparation
I had already roughed up the Motor Mount Fibreglass tube with Grit 80 sand paper and the Fins were already roughed up, scored and cleaned thoroughly.
Preparation included taping up fins, motor mount and airframe so that no epoxy would find its way on to these areas. I didn’t want a hard time getting the lower centering ring back on and I didn’t want to spoil the hard work done on the fins.
I had all the tools out ready to do the job:-
- Safety Googles
- Many pairs of gloves
- Epoxy 105 resin
- Hardener 206
- Cup
- Stiring Stick
- Cardboard to protect bench surface
- Lots of paper towels (some cut up into small pieces)
- Bin
- 60ml Syringe
- 6mm tube attached to 4mm doweling using masking tape
- Methylated Spirits
- Torch
Pictures
Issues encountered
Unfortunately epoxy did on occasion breach the bogs and some would seep out and run along the fins. Hence the tape. Fortunately the seeping of Epoxy was minimal and I think was often due to slightly too much Epoxy, rather than a hole in the bogs. Fortunately after about 30 mins after loading the epoxy, it would start to firm up and not seep as much.