I'll have to do some research. I just know that fiberglass resin has to stick to it. Also some food for thought. I was thinking of using one end of the aquarium as an internal filter. After adding the partition the filter part would be around 500 gals vol., and the tank portion would be closer to 3000 gals. These would be based on the new inside measurements. I'll have to do a sketchup of exactly what I'm thinking, but might help me save some space as with the tank pulled 3' from the wall and measuring 9' from front to back I'm reduced in space by 12', and I'm not sure I can park a car in my garage anymore with the tank that far out. Would also give me more room for my future tank projects. When it's all said and done the garage should have a 3-4k tank, 1200 gal tank, and a 500 gal tank.
I think the tank will look a lil smoother if pushed against the wall and had an internal filter. Could also just make it a filter on each end going about half the depth from front to back. Leaving about 18" of walking room behind the aquarium for maintenance. With the barrel filter system design I'd have to walk on top of the aquarium to get to the filters. So with the behind the filter barrel system the filter will have around 300ish gal capacity with a 3700-4000 gal aquarium, but if I do the internal sump idea it will be 500 gal capacity with around 3000-3200 gal capacity aquarium. All ideas are welcome. The barrels just seem like a pain, and if I do the internal ones I can custom make each chamber to my specifications.