jetpack

My Feedback: (1)

What methods are used to pass tubing through the bulkhead/firewall? Using holes to pass them through would allow oil seepage, and brass tubing is hard to reach with fuel line in the nose of a finished plane. Any suggestions?

Muxje

I've used both methods. When using brass tubes, I make a small access hatch just behind the firewall, which allows me to slip the fuel line onto the tubes. I often make a few hatches in my planes... I don't like having any mechanical stuff or plumbing that I cannot reach or inspect.

On my old trainer, the fuel lines simply pass through a hole in the firewall. The holes are close-fitting without pinching the lines, with the edges slightly beveled to prevent them cutting into the lines. I've found the oil seepage to be minimal over the years I've flown that plane. (of course, you'll want the insides of those holes to be fuel-proofed really well!)

Bax

My Feedback: (11)

Most of the time a 1/4" hole is just about the right size for fuel tubing to pass through the firewall without pinching. As was said above, bevel the holes to remove sharp edges. Very little seepage. If you properly fuel-proof the tank area, a little spray cleaner on a rag from time-to-time is all you'll need...if you have access. Otherwise, wire-tie the tubing to the tank so it can't come off, and then use some clear silicon bathtub caulk where the lines come through the firewall. This gives you an excellent seal that will last for years. Of course you use the caulk before you ever put fuel in the tank or run the engine on that installation.

Starfighter

My Feedback: (78)

Hi, name's Ken(Starfighter). Been at this for 43yrs. now(flying R/C 34yrs.).
On ALL of my aircraft (and those I construct/assemble for others), I take a length of heat shrink tubing, slide the fuel/vent tubing thru it. Carefully apply heat, and shrink the heat shrink tubing to the point where it JUST allows the fuel/vent tubing to slide thu it. THEN, drill the appropriate hole in the firewall and bond the heat shrink tubing in the hole in the firewall with silicone, PFM, Shoe Goop, Zap-A-Dap-A-Goo, etc.
What you've done is to create a non-friction sleeve for the fuel/vent tubing, and you've sealed the opening in the firewall as well.
THIS method DOES NOT result in any fuel seepage,leaks thru the firewall, and your fuel/vent lines WILL NOT chaffe or cut as they are insulated as they pass thru the firewall.
Try this method, you'll like it!

2 Piece

My Feedback: (8)

Here's how I do it on all the planes I build. I run the tank stopper assembly through the firewall. This will allow easy access to all the fuel fittings and keeps the fuel lines from kinking. I never ever use slant tanks or any other type of tank that you have to have the fuel tubings hidden in the fuselage. I center the fuel stopper with the carb, and after everything is hooked up I use a liitle clear silicone to seal everything up with.
Here's some pics of the tank setup on my Nieuport 28 (I hopeI can get them to load)
2 Piece