The Bates SBD design uses completely hidden/internal control linkages for the tailfeathers, check here to see the construction and here to see how it ties into the tailwheel. The linkage utilize 1/8" steel wire joiners into the surfaces, which double as an additional hinging point. In addition to these hinge points, each of the 3 surfaces get 2 of the large Robart hinge points. These were glued in with a waterbase PolyUrethane glue called "Gorilla Glue."
Before hinging, I began by prepping the tail for the hinging and gluing steps. To do this I used Vaseline to lube & protect/seal the hinging "knuckles" of each hinge. I used a toothpic to pack the Vaseline into each knuckle, which will help keep excess glue from getting in there. Next I cleaned the metal joiner wires with alcohol, sanded them, and then used a file to "notch" them providing "barbs" like the Robart hinges. This helps give the glue something to lock onto. I then packed a little Vaseline into the holes where the metal rods enter the tail, and also put a small piece of wax paper over the entire area where these rods sleeve into the tail to keep glue from getting in there.
Now, working on one surface at a time, I glued them on using the following steps. I first use a toothpick, shishkabob skewer, or Q-tip with the cotton removed to apply a little water to the inside of all the hinge holes. Just slightly dampen the surface, as the moisture is what "kicks" the Gorilla Glue. Next I use the same technique to apply a light coating of the Gorilla Glue to the inside of the holes, onto the metal joiner wire, and on one side/half of the Robart hinges. Next I inserted the hinges into the trailing edge of the surfaces about half way. Wipe the excess glue off that oozes out, then push them the rest of the way in and wipe again.
Now apply the Gorilla glue to the other half of the Robart hinge that's hanging out, and slide the control surface on. Again, wipe off the glue as it oozes out. Flex the surfaces back and forth to check the alignment of the fulcrom/knuckle. By now the glue will start "kicking" and begin to foam.
This type of glue will expand to 3-4 times it's volume as it cures, expanding into every nook and cranny and wrapping around the hinge barbs. It is also going to want to expand all over your hinge knuckle, which is why you use the Vaseline, but you still need to keep wiping everything off for about 1/2 hour as it continues to expand. Every few minutes you flex the hinges and recheck alignment. You can also use a toothpick to pick the foaming glue out of tight spots, hinges, etc. After about an hour, the glue is pretty much done and set, but won't fully harden/cure for about a day.
Now you go ahead and hook up servos, set throws and you're all done. I used one HS645MG on the rudder and one on the elevator. I set the elevator to 1" up & down on low rates and 1-1/4" on high rates for now.