Flared fittings - am I on the right track?

[N161WM]

I have been following several threads on creating flared fittings for my fuel system. Before I get started I figured I'd post to my fellow builders for their advice and wisdom, to double-check my approach, and help counteract the Dunning-Krueger Affect:

• 5250-O - based on several posts in this very forum on failed fuel lines (e.g. like this one), it seems that upgrading to 5250 from 3030 is a good investment. Opinions?
• Double Flare - FAA 8083-30 says to double-flare aluminum tubing 3/8" and under. Some of the A&Ps I know say that this is standard for them for stronger and better-fitting ends. More opinions?
• Double Flare Tool - Several folks in various locations recommended the Mastercool (71480) Black 37 Degree Hydraulic Flaring Tool ($278 at Amazon), vs. pro-grade maint-shop tools which cost a fortune. I got one. (vid) Any experiences or words of wisdom with the Mastercool?
• Annealing - Big questions on this, FAA 8083-30 states: "Anneal brass, copper, and aluminum by heating to a dull red and cool rapidly in cold water." But I haven't seen anywhere in builder logs or the EAA how-to videos (like this) where anyone does this. I have a brazier that should get aluminum glowing at the end. Anyone have experience or advice?
• Flare Size - I found this post regarding inspection of flare size to ensure it is the right size. Thanks!
• Thread Seal - Based on this post I have purchased some Permatex Thread Seal for the non-flared portion of fittings. I also have some EZ-Turn Fuel Lube. I was going to use the Permatex on the NPT threads, and the Fuel Lube on the flared threads (not the flare). This sound right?
• Torque - Picked up some crow-foot wrench fittings for my torque wrench to use for torque rather then counting blade-turns. Any opinions or advice with this method?
• Cutting/Bending/Deburring - Got some basic Rigid-brand hw-store tools. These typically work ok? Any tips or guidance for planning bends for routing through the cabin?

Anything I am missing, or I should consider?

Thank you all for your collective wisdom, which has helped me immensely through my RV7a project to-date.

[Ironflight]

Along with teh Dunning-Krueger effect, you shoudl alwso recognize a fiew things about internet forums. Folks rarely post about what is normal - so you get ore posts out at the far edges of the bell shaped cure. For instance, I know a goodly number of folks use 5052 insted of the soft tubing that Van's supplies. But I would guess that of the almost 10,000 RV's flying, maybe 8,000 of those used the Van's supplied tubing, and they are doign just fine. And it sure is easier to shape! Of course, you don't get the bragging rights that come with using the more expensive stuff that way....

Annealing? Never heard of anyone doing it to their fuel lines. Cut them, dress the ends, flare them to spec, and install.

Van's "Section 5" works pretty well if you want to get the airplane finished and flying safely.

[Rupester]

- alternate fuel nine metal/material?
You can if you want but it's not necessary
- Double flaring?
Same as above ... Simply not necessary
- annealing?
Unnecessary. Waaaaay too much trouble for simple fuel lines.
- sealant?
The a Permatex is fine for NPT threads; I would use no lubricant on the flare fitting threads
- Crow's foot for torque wrench ?
Sure. No problem.

I fab' my fuel lines very early in the build and kept them absolutely basic. I have never had any of those "neophyte" flare joint leak .... Not once.

[Carl Froehlich]

Fully agree with Paul.

Before applying solutions, make sure you have a problem. I have 15 airplane years using the tubing provided by Van's. The only flared fitting leak was one of my first ones where I overly tightened the flaring tool. Once I figured this out I never had another leaker.

I recommend the standard aircraft flaring tool for all applications: Roto-Flair 37 degree, ACS part number 212FB.

I never use anything on flare fittings or nut threads. I use Permatex 59239 Teflon thread sealant for all pipe fittings.

Carl

[Auburntsts]

Yep making flares ain't hard. Here's the link to the tool Carl mentioned: http://www.aircraftspruce.com/catalo...?clickkey=4577

$105 and works like a charm.

[BobTurner]

If you lubricate those flared fittings threads then the recommended torque will be wrong.

[BillL]

use the nominal torque recommended. I did lots of testing (confusion induced) and standard torque was confirmed.

Do add a drop of Boelube to the flaring tip during flaring. The RoloFlare (and others) is really easy to over torque when making flares, so be gentle and practice.

[Rick_A]

If you really want a professional grade flaring tool, try this one http://www.aircraftspruce.com/catalo...ringtools1.php

Or even better, do like I do and share a hanger with someone that has one and will let you borrow it.

I never heard of the Dunning-Krueger effect but that the funniest thing I've read in a long time.

[Bevan]

I too used the tool Rick links above. Being a tubing rookie, I knew I needed all the help I could get. That means aquiring great tools and taking the time to practice with them. The above tool also allows work in tighter spaces which is sometimes useful. No leaks so far.

Bevan

[crabandy]

If the Nut won't slip over the flare and must be threaded over the flare the flare was over torqued.