R

Rupester

Well Known Member
I need some ideas how to flare a 3/8" fuel line when there's only 1/2" of straight tubing available at the end. The Parker Rolo-flare requires 3/4" of straight length at the tubing end for its internal "clamp". Because I have a 90-degree bend close to the end, the radius plus the 3/8 ferrule/nut only leave me 1/2 of clear tube at the end. This is 3rd time I've fabbed this fuel line (I finally have all bends PURRfect)... but now I have this flare problem.
Anyone got any slick ideas?
 
Flare first and then bend? I had some pretty tight bends and flairs on my electric fuel pump installation too. How about a right angle or 45 degree fitting, or a "Banjo" fitting. Check out Andair.

Anyway, don't compromise your quality standards on fuel line fabrication. In my humble opinion, this is one of if not the most critical parts of the fabrication process for our planes...
 
You could use...

..one of these fittings to do the 90 degree bend.

An "AN Male to AN Female 90 Degree Swivel Coupling"

AAACPL903.jpg


It's not an AN part, so it comes from race car supply houses.
 
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Parker flaring tool.

Parker Flare tool. A WORD of CAUTION! On the tool itself. The clamping wheels have been making marks in the tubing after clamping that warrant a looking into. On my Parker tool (called Parker tool co and retailer about problem) you have the valleys where the tubes lies prior to flaring, its the back side of the valley (about three quarters of a inch from the flare) where the marring takes place after flaring. Open your clamping assembly. Then rotate the wheel so you have this groove where you can run your finger over the valley EDGE. Use your finger nail over the bottom of the edge and sides. You made find a razor sharp edge of raised material that causes the marring after flaring. Remember this is NOT the side where the flarring takes place but the other end of the tubing valley in the wheel. I asked several people to look at the ring of marring taking place about three quarters of a inch from the flared end. We used a 10X power loop to check out the marring. I made some simple strokes to file down the RAISED edges with a three sixteenths round file. This proved to fix the problem with the marring on the tubing. I also found the raised edges on a friends Parker flaring tool. My point here is this could be a fracture point in the tubing at a later time I'am told. After filing I had NO marring of the quarter inch tubing I was working with. Please let DARs know of this, APs and everybody else. Thanks builders. Ron in Oregon
 
I've noticed notches directly behind the flare on mine.

When you thread the male die into the tube, the tubing gets pushed into the seam formed by the clamp. (Female side)

I could understand this happening if I was smashing the tubing between the male die and the clamp, but I'm not. Just a moderate twist with the fingers and you can get the notches.

I've backed of the pressure some and it helps a little, but it's still not very predictable.

Back on topic:
I made a similar bend last night. I flared the end first and then gently shapped the tubing (with my fingers) around the bend channel in my benders.

Since it was so close to the end, the tubing wasn't long enough to "catch" underneath the support bar. That's the reason for using the fingers, but taking it slow worked fine.

Phil
 
Old trick

Tapa-tapa tapa... Way out in the bush and you have to fix a flare? I flared this in just a few taps, hand held, Craftsman 5/32 (37?:D) socket, 3/8" tube, ferrule in place. works just as good as my fancy pants flair tool.
My dad fixed our ob motor way up in canada using a bent nail to make a new flair!
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Slick ideas ....

... are what I asked for, and as always ya'll came thru with some good ones. Thanks much, as always.
 
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