Before we continue, here are the materials used:

Utility Knife (used to cut matting)

LOTS Sandpaper (150grit, 400grit, 600grit, 1500grit) - we used 15 pieces of 150grit, 10 of 400grit, 5 of 600grit, and only 1 1500grit

Fiberglass Matting (reinforce the inside)

Fiberglass Resin Jelly (available at Advance Auto Parts)

Craftsman Power Finisher & Sander (saved us lots of time)

Cardboard (to mix resin with hardener)

Puddy Knife (to apply resin)

Scissors (to cut fiberglass mat, string, double backed tape, and sandpaper)

String (to hold bumper together, you'll see later)

Double Backed Tape (to attach sandpaper to sander)

Water (to dampen paper towls to clean bumper before primer)

Paper Towls (you'll need at least one roll)

First thing we did with this bad boy was set it up in my basement. We attempted to get the crack together as much as we could. We duct taped the front of the bumper together in the front. This held the bumper together for a short period as we applied fiberglass resin to the inside. We did not do the entire bumper at once. The top was put together first, then the middle, then the bottom. It was too difficult to completely do it in one shot.

After this was accomplished several layers of fiberglass matting was applied. We used the fiberglass resin to hold it in place. We put it on thick because this is the point of breakage, so it needs to be reinforced heavily.

Basically we did about 5-6 layers of this stuff to make sure it wasnt going to break easily.

Next is the hardest part.... sanding. We started with 150grit. No resin was applied to the outside

A closeup after sanding for an hour.... long way to go yet. The crack is no where near smooth yet

After about another hour of sanding with the power finisher, the crack was pretty smooth but you could still feel a hairline crack there.

Now we rubbed some resin over the crack in the middle. Thats where it seemed to be the worst.

Next we noticed the top and the bottom needs to be reinforced also. We applied it heavily on each end. We didnt bother to do a good job on sanding at the bottom because this is the bottom. Strength over cosmetics.

Now the top was a different story. This needed to be flawless on the outside while still being strong. We noticed that the bumper needed to be pulled inward for the crack to seal, so we doctored up some string and tied where the bumper lights would be. This helped hold the bumper's integrity.

After it all dried, we sanded both ends with 400grit sandpaper and then again with 650grit.

Now the entire bumper was sanded with 400grit sandpaper, so it is ready to be primered.

We sanded this with 800grit and then 1600grit to finish it off. You could barely feel the crack at this point, but nonetheless feel it. So we used sandable primer in this area. We sprayed about 7-8 coats of it and then started going to town with 400grit sandpaper. This smoothed out all the cracks and made it almost perfect on the exterior.

We finished up by priming the entire bumper. Now you cannot see or feel the crack at all. If you happen to use this tutorial to fix your bumper, always remember. The most important part of doing this job is sanding. The total job took about 10-13 hours of work, with at least 8 hours being sanding.

Here are some finishing pictures: