Well for one…when you are doing a patch job with Fiber-glass resin. It usually involves using a fine mesh fiberglass cloth, not the stringy fibers. To start off both surfaces need to be sanded…the resin is mixed and a light coat is applied to both surfaces, cloth is applied and a layer of resin is brushed on top of that working it all over the mesh and overlapping on to the surface with the acid brush I mentioned. Once cured…you have to resand the whole area with what is called a DA (orbital air sander) to smooth out any high spots and also take off the sheen of the cured resin. In most cases, you have to repeat the process to get a thicker build-up of the resin. That will make the parts extremely strong. Then you sand it again and this time, you use the fiberglass bondo over the whole area. This is the part that most back alley repair guys mess-up, they don’t use the mesh and resin first before the bondo and it will crack every time. In modeling with resin, we can get by with just using the resin and also gluing parts together with resin as long as you always sand down the shiney surface. Modeling with resin can be done without the mesh cloth simply because the model does not go through vibrations and stress as in 1:1 use. I use to repair one piece molded fiberglass hoods for trucks and never had a customer come back because of a broken or cracked hood that I repaired, including paint. Now We are talking big money for a new fiberglass hood…starting at 6,000 dollars and up. Sometimes You can find a decent one in a truck graveyard which only requires minimal repair, but it’s still going to set you back about 3,000 if you can even find one that you need…been there…
Rich, I had no doubts that it would work…if done correctly…You should be able to add more to those pieces if You would like…keeping them square and flat is what you need…may have to make some sort of jig to keep inplace while curing.
Good Luck, on Your Project! I have great confidence that You wil