Grind off all the paint in the repair area. 'countersink' or dish out the area thats actually cracked. Do this on the inside and outside of the part. Get a fiberglass repair kit at somewhere like Autozone that contains the resin, hardener and cloth matt. Cut the matting with scissors to fit the area...one for inside and one for outside. Mix the resin and lay the matt in it, then apply that matting to the area. You can use some wide masking tape to hold it in place if needed. When its cured, sand down and apply another layer if needed. You can finish it off with regular filler or do like I do and use Dynaglass filler. Its filler with glass strands mixed in it.. Sand and primer, paint as any other part. I usually leave the inside patch unfinished for the most part other than just smooth down the edges. Thicker will give it more strength. If you dont use matt or do the inside too, it will crack back pretty easily. Use of latex gloves is recommended
The cracks on the running board are near impossible because of the diamond pattern. Fix the glass the same as above, but Id make some metal replacements to bolt on over the top. If you dont want to do that, you can just use something like bedliner to put some texture on it. You could match the original, but it would be time consuming or expensive to have someone else do it. Ive done parts where I finished it all smooth and make myself a little casting of the pattern. Then put a layer of filler over the area and press my pattern casting into it before it hardens and only lightly sand the edges before painting it.
[This message has been edited by rogergarrison (edited 08-29-2011).]
