Not many pictures tonight, but I did get the tank matchdrilled.
But first, I got some things ordered from Van’s today in preparation for the tank sealing process:
- 60 x BUSHING SB375-4 Snap Bushings, 3/8 (1/4)
- 1 x DUCT NT 5/8-25 Nylon Conduit
- 30 x BUSHING SB437-4 Snap Bushings 7/16 (1/4)
- 2 x IF-4/6 RV-4/6/6A/7/7A/8/8A Wing tank flop tube
- 1 x MC-236-B2 Tank sealant with accelerator QUART KIT
- 1 x FUEL TANK TEST KIT Fuel Tank Test Kit
Of course, once I placed the order, I remembered that I buggered up the inboardmost rib of the right leading edge and needed a new one. I need to remember to order that one, and BEG Van’s to send it in the same shipment.
I decided to go with 2 flop tubes. (Flop tubes allow the fuel pickups to flop around in the tank, and therefore sustained inverted flight.)
One school of thought is that if you have two flop tubes and they get stiff, you could increase your unusable fuel (they don’t flop good no more) in either the upright or inverted attitudes. People therefore put one flop tube in and one rigid pickup. This means you have to switch tanks to your “aerobatic” tank before doing negative-g aerobatics. (How often will I do sustained inverted flight? Probably not very much.)
Anyway, I weighed the pros and cons, and came to the conclusion that the aesthetics of not having a single tank for aerobatics, and therefore a checklist item or a special placard, outweighed the possibility that after 10 years, my tube wouldn’t flop as floppily as it did when it was young.
Every couple years, I’ll open up the tanks and verify adequate flopitude. They are only $38, so it’s probably worth replacing them every 5 years anyway.
So, now that I’ve settled on duel flopicity, let’s get back to building.
I decided while matchdirlling, it would be easiest for me to do it while it was on the spar, so up on the spar the tank went.
(Be careful though, Van’s notes to matchdrill off the spar to avoid damaging the spar. This is really only a concern with the baffle holes (about the 10 most inboard ones). Take the tank back off the spar do matchdrill those.)
Next up is fuel tank stiffeners, then a lot of prep before assembly of the fuel tanks.