I have the double flaring tools and i have made many flares in the past .Although they hold up,they never look like a factory flare. Anyone care to run through the process, there seems to many variables like how far the tubing should stick out of the clamp when doing each step.

Here's how I do it - sorry for the technical terms, but its hard to describe by typing.

First make sure you cut the end clean with a tubing cutter (wheel type) and you remove any burs so the cut edge is smooth and square. IMO this is the most important part for getting a good factory look to your flare.

Put the fresh cut end of the tube into the flaring bar and position the tubing so it is sticking out the flaring bar the same as the thickness of the shoulder on the flaring adapter. (the flaring adapter is the disk shaped part with the pin in the middle). For really hard metal line I let it stick out slightly less.

Drop the flaring adapter into the tubing and tighten down with the yoke (the screw thingy with the cone on the end) until the flaring adapter piece is flat against the flaring bar.

Remove the flaring adapter and finish the flare off with the cone shaped piece on the end of the yoke.

Eric 68 is dead on, and I can offer some more advise. One of the biggest problems I have had is that the tube will slip in the clamp while making the first "crimp." I have a Craftsman set, I'm not too happy about it, but have figured out how to make it work. It is paramount that the tube doesn't slide, if it does, you will never get a better clamp on the piece, and you will have to cut it off and do it over.

Do a real good job at de-burring the end of the tube after you cut it, and make sure that it is square on the end. File that sucker, put a good chamfer on it, all the way around, don't be shy. Also take a small rattail file and debur the inside. When you put it in the clamp, tighten the clamp a bit until the tube can just barely spin the tube. Turn the tube back and forth, about a quarter turn, two or three times. This will give the clamp something to bite into, and will help prevent it from slipping. Then tighten the clamp as tight as you can get it. Use pliers, I also put half of mine in a vise to clamp it more. All of this might not be necessary if you have a good double flare set. Otherwise, follow Eric's directions and you'll be fine.

Ok,the way i was tought was to leave the tube sticking out about an 1/8 inch over the bar,use the cone thingy first,then slide the tube up some more then use the adapter.Hmmm. i guess i have been doing it wrong?Thats why i asked,i'll have to go try it out. I know what you mean about the cheap tool.I have one i bought at advance auto parts,and i crank it tight like you said and it actaully makes the tube oval shped!Never gonna get a good flare with that! http://www.click-smilies.de/sammlung/sauer/angry-smiley-055.gif

The amount that you should leave the tube out of the end depends upon the diamater of the tube you're trying to crimp. On the round thingies, there is a shoulder. The length of the shoulder is the amount that the tube should be sticking out for the first crimp. After that, you do not need to move the tube again, you're all set for the inverted part. Again, I cannot stress that doing a good job with the deburring of the line is super important. I have just gone through trying four different master cylinders, just completed a rear disc conversion last night. I must have made 30 flare crimps in the last month, and most of them were screwed up until I did this mthod. Works right every time now, even with my old, cheap flaring kit.

I finally broke down and bought a hydraulic flare tool and it works.
My most common problems with my Imperial Eastman manual flare set was the initial "upset" operation would squash the tubing off to one side.

Some tools have a different shape to the upset tool or insert. My Eastman tool has a large radius to the pin that comes out of the tool. My hydraulic tool does not, the pin comes straight out with next to no radius at the root of the pin.
It think this affects the way the tube rolls (or fails to roll) inward when doing the first operation.

Also, brake tube that has been rolled in a coil and then unrolled can retain a very slight curve to it that can make it squash to one side.

If your first flare is bad, and you try to reflare in the area the tube was clamped before, the tube is usually squashed there and can cause problems.

I have some bundyflex tube that fails to flare over and over. I switched to a different piece of tube and had no probems, so some tube is just brittle or something, at least for the manual tool I was using.

I have heard good things about the Snap-On hand flare tool.
David

Here is where we talked about tube flaring a while back:
http://www.camaros.net/forum/ultimatebb.php?ubb=get_topic;f=7;t=004349#000000