I am installing some new fuel line and had to cut off the double flare that came on it in order to shorten the line a bit. I've been trying to put a new double flare on the end to no avail. No matter what I do, the tubing backs out of the flaring tool when trying to do the first step of the double flare process with the insert you put on the tube. I've tried two different flaring tools (one of which I broke the wing nut off the end trying to tighten it). I tried clamping both of them in a vice, as well as adding C-clamps to add extra pressure and the tubing still pushes out. The tubing is regular steel, not stainless. Anyone have any tips as to how to keep the tubing from backing out of the tool? Also, this is the end of the tube where it ends at the gas tank and you connect the short piece of fuel hose to the sending unit. Since it is not under pressure, does it even need to be flared?