Calling all autobody guys for opinion

K, i’m fixing my hatch.
The previous owner put a 2 piece metal patch in and then bondo’d the crap out of it to round off the corner where the 2 patches meet.
My question is: Is there a better way to repatch it because I don’t want the bondo to crack like the last time. I have a welder so i’m welding the patch in but i’m wondering if there is some better way to maintain the outside curves of the hatch.
http://img296.imageshack.us/img296/9379/hatch1nov706aq9.jpg
http://img452.imageshack.us/img452/952/hatch2nov706tw4.jpg
http://img452.imageshack.us/img452/4896/hatch3nov706vu4.jpg
http://img464.imageshack.us/img464/3303/hatchrepair1nov806sg6.jpg
http://img98.imageshack.us/img98/9775/hatchrepair2nov806df5.jpg
http://img464.imageshack.us/img464/3001/hatchrepair3nov806gm4.jpg

shaoe the emtal to the curvature of the hatch before you weld it in place.

or try some fiberglass and manouver it to your curvature.

must have been a shady job for the bondo to crack. If it was done properly on the hatch then it should have been fine…u could always use the bondo hair…it has fibreglass in it…

use one piece pf metal make pie cuts as nessasary to get the curves right then weld it all up make sure your spacing out your welds to help prevent warpage canadian tire have a curve gauge they are cheap and can be gods hand in getting the body lins right.
filler will most tiems need to be used but when it is very thick thats when it cracks, try to keep the filler as thin as you can.

the hatch on my 180 is similar had a big wing on it at some point and some one bondoed the holes closed. so this winter i get to fix someones mess properly