Flaring Fuel tubing?

[TJ_Slice]

This is something I have no experience with, so I cut off some small lengths to practice on. I am using the High Duty flaring tool: https://www.aircraftspruce.com/catal...?clickkey=4577

The 3/8" ones have come out well, but I am having an issue with the 1/4" lines... at least I think I am.

The flare comes out fine, but the tool is leaving witness marks along the tubing. The one I concerned about is where the tool ends, about 3/4" from the end of the tubing.

The score mark it leaves can be felt with your fingernail. My gut tells me this is not normal, especially since the 3/8" one doesn't leave that mark.

I have attached a photo.

[alaskabearhawk]

That looks like a no bueno to me. I used a Rolo-Flare tool and it doesn't leave any marks. Can they be polished out? 3003 tubing is soft and wall is pretty thick. I'm not sure if 5052 tubing would be a candidate for that.

[TJ_Slice]

The marks between the bottom one and the flare can be polished out. The bottom one can’t. I think I’m going to try a chainsaw blade file to smooth out the ridges in the clamp to see if that helps.

[Bcone1381]

That is what I was thinking too....fix the tool where it leaves the impression and maybe followup/polish your filed area with a finer abrasive. Doing stuff like that will somehow transform a tool from being "THEIR tool (meaning the manufactures tool) into it being YOUR tool.

[Dpearson]

I had a similar problem when I first tried my brand new Rolo-Flare tool. It left a score right at the end of the clamp area due to a sharp edge. Like Bcone1381, I filed and polished the tool as needed to get it to yield good results.
caveat: I’ve never used the tool that you have, maybe there are some “teeth” in the clamp area to keep the tubing from sliding ? Probably don’t want to file those down too much…..

[arborite]

Had the same issue with the rolo-flare tool. those things used to be great back in the day, but the one i got left deep witness marks in the tubing and the jaws didn’t align well for the small tubes, causing asymmetry in the flare. i returned it and got a different tool, the ATS imperial. the new one is much better but still leaves small marks in the tube to keep it from sliding. light marks i can live with.

try to find an old used Rolo-flare. those are the best.

[TJ_Slice]

Thanks for all comments. I filed and sanded the clamping area, especially on the end, and it is much improved.

[TJ_Slice]

Another question: Is it acceptable to have a little bit of resistance when sliding the sleeve toward the flare? The 3/8" once don't have any. The 1/4" lines have just a touch about 3/4" from the flare. Once you push past it, is slides smoothly. I don't see anything visible on the tubing, but it obviously is deforming just a tiny bit when flaring.

[alaskabearhawk]

It will be fine. It might even be a bit of an advantage. I always had to use a bit of masking tape to keep the bits from sliding too far down the tube. The B nut has plenty of clearance anyway.

[TJ_Slice]

Thanks, I'll steal that idea.