This is kind of a "testing" question, and here's a 35-year-old answer, from when the stuff started appearing in R/C ARFs in the early '70s. There are two solutions that I remember. For completely hidden joints, use some lightweight fiberglas cloth (1 - 2 oz per yard) cut into a strip thats about 30% as wide as the joint is long (i.e., for a 3" joint, use a 1" wide strip the correct length), and use Oates Plastic Pipe Glue. This stuff is black, and virtually unpaintable - that's why it's for hidden joints, but it is fuelproof.
For anything that's going to be visible, try a reinforcing strip of ABS on the inside with the whole thing stuck together with Methylene Chloride, the same stuff used for styrene or Acrylic plastic. sand the joint with 220 to provide a bit of "tooth" and prime with your favorite secre3t blend. Brodak's Primer should work, but I haven't tested that.
I think I remember that MEK works also, but Acetone evaporates too fast to bond properly. ABS is tough!