Three things right off are to make sure you are using the right side of the clamp barn (the side with the countersink), that the clamp bar is clamping well enough that the tubing does not slip through the clamp, and lastly that the proper amount of tubing is sticking out of the clamp before you start.
If it didn't come with directions, on most sets the amount of tubing to leave sticking up is the same as the thickness of the proper die. The die then goes on the tubing end with the pin in the tube, then you tighten the clamp down until the die hits the clamp bar. Then you pull the die and just run down the clamp right tight.
The first step should leave you with the 'bubble' on the left piece here:
It doesn't have to look really great when you are done, quite a bit of 'reforming' happens when you tighten the flare nut. In fact, I have done 'bubble' flares in a pinch a few times by doing the first step and then just installing the thing.
It's important that you start with the correct amount of tubing "sticking out" of the clamp bar (I think the HF tool uses the shoulder of the adaptor as the height gage) and that you use the correct adaptor so the internal mandrel size is correct. The first shot is using the button adaptor (with the internal mandrel) to form the "bulge"... then you remove the adaptor and force the cone-shaped tool in to form the tapered "seat". It's really too simple to do it wrong, if you have the right tooling.
"Stormin Mormon" wrote in message news:q9yor.5974$ firstname.lastname@example.org...
After the tube is cut with a tubing cutter the first thing you have to do is square off the end of it making sure there is no inside burr. It also wouldn't hurt to very slightly chamfer the I.D. and O.D. Phil k.