Kdec, did your lattice structure allow for the liquid resin to be drained?
We have had very good results using our 3D Systems machine with solid mold casting with pour weights at up to three pounds. We do not use Quickcast technique. However, you must have a dwell time at 300 degrees F for a few hours and another dwell at 500 degres - otherwise extensive cracking will result. We still see occasional cracks. Maybe the solid mold is stronger and tolerates a bit of cracking without exploding. We also try to minimize section thicknesses which helps, too.
Solid mold technique may not fit in with your foundry or your part is too large… Lack of foundry ability to deal with RP patterns was the main reason we do it ourselves.
Also, we have made large parts (for us) using a modified silicone molding technique. (We have even injection molded styrene!) You can get a lot of rubber mold with fiberglass backing techniques from youtube. It has worked for us.
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