Fuel drain fairings and NPT taps

[Flying Scotsman]

I have a pair of these:

http://www.jdair.com/fuel-drain-fair...s-rv-aircraft/

which I'm installing, and I have a quick question for anyone who has used them (or might have an idea here).

Tightening the drain itself is insufficient to hold the fairing in place against the flange of the drain port. If anyone has used these, do you a) use an NPT tap to *sloooowly* allow for more insertion of the drain valve, or b) use some sort of gasket between the fairing and the drain port on the wing?

If (a), where do you procure one of these boogers?

AND, any warnings, gotchas, tips or advice on how NOT to f*** this up are MOST appreciated. The one thing I *don't* want to do is have to tear into my tank to fix a stupid drain because I goobered something up there...

TIA, as always...

Steve

[Ron Lee]

Steve, I would call the folks you bought them from and get their advice.

[N427EF]

I have also bought a set of those and spent a great deal of time wondering
how to secure them to the drain.
Just couldn't see how clamping would work without some kind of gasket and I sure didn't want to make several attempts and have to remove the fuel drain every time.
Here is what I did:
I drilled the drain hole all the way through so it would fit flush on the skin and the drain flange. The hole is large enough to accept a socket to access the drain plug for service removal.
I filled the hollow fairing shell with epoxy filler for a precise fit to the skin.
Filling the fairing allows for a larger bonding area.
Pro Seal it onto the skin.
Mine are not bonded yet and still need to be painted before the final step.
A little elaborate maybe but I am done with my airplane and I was looking for something to work on.

[Snowflake]

I used an NPT tap to remove some meat from the drain threads. I forget how much, but it wasn't much. I don't think I needed a full turn.

[douglassmt]

If I recall, all I did was put a large AN washer between the drain fitting and the fairing. Works great. No messing around with threads. No leaks.

[bruceh]

I got them on as tight as I could and they still had some play, so I put a bead of proseal on the flange and around the outer edge. Now they are glued securely in place.