Please take a look at the pics in my gallery

240 Z flares

I need to cut the bottom 6" of the flares as they will interfere with 16x8 wheels.

What do I use to cut the fiberglass cleanly? Also, do I need to seal the cut edge after sanding it down, before paint?

Any help is appreciated as always.

uberhahn

When I've cut Fibreglass panels before, I've used either a Jigsaw with a fine toothed blade (a metal blade will work) or a Sawzall, again with a fine toothed blade. Also cut it one time with a small air grinder and cut-off wheel but that created a CLOUD of dust.

Regardless of the method you use to cut, you want to wear a full body coverall, tape the sleeves to your wrists, wear gloves over the taped sleeves AND wear a full head sock. A head sock looks like a winter ski mask. The mask should extend down below the neck of the coverall. Over the face mask, DEFINITELY wear a particle mask and safety glasses. Why all the protection? Because the fine particles of GLASS you will be sending into the air, LOVE to work their way INTO your pores and skin giving you the worst case of itch you'll ever have. That's why the Jigsaw with a vacuum attachment (if you have it) is the best way to go.

As far as sawing, you don't want to cut right to the edge of where you need to trim to. Fibreglass, regardless of how slow and careful you are while cutting will tend to shatter and bristle at the cut end of the downward stroke. You'll want to sand that edge down with a D/A sander / grinder. Use the saw to get close to the edge, then grind / sand to the final contour.

FWIW