Fuel tube alloy

[DesertBearhawk]

What is everyone using for fuel tubing? I see options of 5052 and 3003-O. What have you used, and why?

[Mark Moyle]

Not on my Bearhawk...a Pacer with an 197hp O320. 3/8” X 0.049” wall 5052. I’m in the warm north on the Bering Sea Coast... The Trimmer STC with a Maule fuel valve gives the option of either 3003 or 5052. I like the rigidity of 5052 and it’s ability to hold shape...pain to work compared to 3003.. every low spot has a sump and Curtis drain valve...no sags anywhere in the fuel lines like you get with 3003..sags in the line may trap water that may freeze, limiting or blocking fuel flow...no insulation in the airplane even though I’ve flown regularly when temps are well below zero. I also used single and double layers of shrink tube to protect the line where it may rub or be exposed to any wear and tear.

[Rollie]

I used 3003 from the tanks to the electric pump and 5052 downstream of the pump where the fuel is pressurized. Of course the 3003 could easily handle the 30 psi but it made sense to me. I also used 5052 for the brake lines, at least the parts that aren't stratoflex.

[rodsmith]

Either is fine. The advantage to 3003 is cheaper shipping if you need long pieces. If using 3003 roll out the length you need and get it as straight as possible, then use a tubing bender to make your bends. Can be tweaked a little if your bend isn't perfect. Like Mark, I used heat shrink tubing anywhere the tubing was close to or in contact with structure.

[Archer39J]

5052-O for corrosion and fatigue resistance. 3/8"x.035" for fuel, 1/4"x.035" for brakes.

[Bcone1381]

Either is fine. The advantage to 3003 is cheaper shipping if you need long pieces. If using 3003 roll out the length you need and get it as straight as possible, then use a tubing bender to make your bends. Can be tweaked a little if your bend isn't perfect. Like Mark, I used heat shrink tubing anywhere the tubing was close to or in contact with structure.

Straighten....put one end in your vice and hold the other end with vice grips. Then whack the vice grips with your dead blow hammer.

I didn't let my tubing touch any structure. It's secured every 16" or so with standoffs or Adle clamps.

[Mark Moyle]

My concern with 3003 is how easily it will dent or get crushed. Especially where routed from the rear fuel tank fittings down the rear door posts. Most capture or secure the tubing with fabric when they cover the interior.

I know I’d be very careful loading and unloading...but others do not. You know the type...they’ll slam the door on your brand new car or truck...they just don’t think about it.

I choose to create nooks to tuck the tubing out of harms way then made aluminum covers.

[JimParker256]

Very nice, Mark!