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Pete C.

Don Foreman wrote:

On Sat, 11 Sep 2010 00:12:36 -0500, wrote:

My 2500HD Chevy needs a gooseneck hitch. Unfortunately, there is a
heat shield that must be removed or a section cut out. Every shop I've
spoken with says the heat shield fasteners are installed with
something like Locktite and are almost impossible to remove.

Their parctice is to cut a section out with a plasma cutter. That
shield is 1.5" from the bottom of the bed which has a spray-in liner.
Should I be concerned about burning the paint off the bottom of the
bed or blistering the liner? I've only seen plasma cutters used on TV
or the internet.

1.5" is as good as a mile with plasma. Interpose a sheet-metal shield
or weld blanket between cut and bottom if severely anal.

Agreed. One of the benefits of a plasma cutter is their very low total
heat input. They give you a super hot plasma stream, but it is small
diameter and cuts so fast that you don't dwell in any area very long so
the piece being cut doesn't get very hot, and the thinner the material
the faster you go. On painted sheet metal, the paint gets burned back
less than 1/8" on either side of the cut line, and that's on the piece
being cut. A surface 1.5" away from the cut will just get sprayed with
the vaporized metal and that spray will have lost most of it's heat in
that 1.5" of travel.