chepburn
Well Known Member
Hi all,
I have been flaring my 3/8 fuel lines...and I thought I was done. But....
The short story:
..how many many turns of a Rolo-flare should it take to get a 'good' flare on a 3/8 aluminium fuel tube?
The long story:
The "instructions" on my Rolo-flare tool tell me to put the tube against the flare stop in the tool, then rotate the burnisher "until there is resistance" Hunh? How 'much' flare is 'enough' flare?????? and how much is 'enough resistance'????
Well, I looked at the Aircraft practices guide, and it's only guidance was a cut-away of the flare which shows the flare edge just proud of the collar fitting. OK...copy that. When I did it this way, the inside of the tube is burnished, and the outside of the tube is only slightly distorted, and the tube is just proud of the collar (about 1/128") This took 1 and 1/2 turns of the burnisher. Tighten the AN fitting over the collar till its hand tight, then wrench turn it a flat and a half. Hmm...that seems to have very little torque resistance. Torque it another flat...no change. You guessed it, the tube had formed itself back to straight and slipped through the collar.
OK. Try again, only this time, I turned the burnisher 2 1/2 turns...(the 'until there is resistance' advice doesnt work for me...I have nothing to compare to.
The flare is now about 1/16 proud of the collar, I can turn the fitting tight, then wrench it 1 -1/2 flats....torque is going up as I think it should.
But I AM NOT SURE. I want to be. See question above.....
Thanks for your help,
Chris
I have been flaring my 3/8 fuel lines...and I thought I was done. But....
The short story:
..how many many turns of a Rolo-flare should it take to get a 'good' flare on a 3/8 aluminium fuel tube?
The long story:
The "instructions" on my Rolo-flare tool tell me to put the tube against the flare stop in the tool, then rotate the burnisher "until there is resistance" Hunh? How 'much' flare is 'enough' flare?????? and how much is 'enough resistance'????
Well, I looked at the Aircraft practices guide, and it's only guidance was a cut-away of the flare which shows the flare edge just proud of the collar fitting. OK...copy that. When I did it this way, the inside of the tube is burnished, and the outside of the tube is only slightly distorted, and the tube is just proud of the collar (about 1/128") This took 1 and 1/2 turns of the burnisher. Tighten the AN fitting over the collar till its hand tight, then wrench turn it a flat and a half. Hmm...that seems to have very little torque resistance. Torque it another flat...no change. You guessed it, the tube had formed itself back to straight and slipped through the collar.
OK. Try again, only this time, I turned the burnisher 2 1/2 turns...(the 'until there is resistance' advice doesnt work for me...I have nothing to compare to.
The flare is now about 1/16 proud of the collar, I can turn the fitting tight, then wrench it 1 -1/2 flats....torque is going up as I think it should.
But I AM NOT SURE. I want to be. See question above.....
Thanks for your help,
Chris