Sonex Fuel Tank

[chrisyk]

Re inspection camera. You can buy a cheapy on ebay for around $20.00 I have one and it actually works. Most of them are 640x480 but I bought a 1280x720 for $25.00. This is perfect for a job like looking in a (empty) fuel tank. I haven't tried yet but it might work for inspecting valves through the spark plug hole. These inexpensive ones plug into your USB port on a computer, and use the computer screen.
Look under "endoscope" on Ebay.

[Don_P]

I've been following this thread to see if anyone would comment on pipe-thread fittings in the fuel system. Haven't seen any, so here goes: I'm plumbing a Onex (0095), and several of the fuel-system fittings are NPT, such as the finger stainer and the fuel shut-off valve. I understand that the general rule of thumb for screwing in an NPT fitting is to get it finger tight, then snug it up with a wrench, but making only about one and a half or two turns. When I do this, I can get the male end to go in only about three or four turns, which puts the fitting in only half way. I'm concerned that this will not make for a good, no-leak seal. Where possible, like the female fittings in the tank, I've run a pipe tap through the fitting (as per Sonex instructions), and this solves the problem, but this is not always possible, as in the case of the fuel cut-off valve, where the tap immediately bottoms out in the fitting before doing any serious cutting. Is an NPT fitting with only half the treads engaged an acceptable practice?

[EricS]

Hi Don, I understand exactly what you are talking about because I was working on my tank-to-firewall plumbing today. The fit is tight and I think you will have better luck if you put some fuel lube on the threads of all the fittings. I use the EZ Turn Lubricant that Joe was referring to earlier. It works great as a gasket/sealant, won't harm the fuel system, and helps you get better thread insertion.

Here's the link to the product on Aircraft Spruce's site: http://www.aircraftspruce.com/catalog/cspages/ezturnlube.php

Let us know how you make out!

[Don_P]

Thanks Eric. I'll get a tube of this and try it out.