.60 biplane, with ailerons built for top surface mounting, but not much material there. Tail has Robarts, but an attempt to top hinge the ailerons with Robarts was not very clean - no easy way to jig as there is a sharp point on the top where the 45 degree undercut come up. Not much wood to slot into either. So, I'm wondering what whould be the best option and strong enough to get the job done. Options I'm looking at are below but any input or ideas as to which is best are welcome. Planning on Polyspan with urethane paint....

1. Cover n finish then rough up lower and use CA hinge. Then seal up top with 3m book tape (i've used book tape on gliders as just the hinge but here it would be for backup)....

2. Hinge as above but also use CA on top before covering - not sure how this would work out as hinge line would be flexed on the top and I'm sure cause issues with the paint....

3. Stitch Polyspan and glue in during covering - same issue with paint above..??

4. ?????

Any ideas on what is the best option. Again - too little wood for slotting and top hinging without aileron rebuild, Robart attempt not good. What will work and hold for acro on this size ship..??

Thx....

another option is to install a "fiberglass" hinge ........... this is just a piece of fiberglass around 2 inches wide ran the length of the surface to be hinged. when the resin is dry sand smooth and flex the surface (it will cause the resin to split and crack as needed) sand it smooth again and when satisfied with the finish just cover over the wing, joint, and control surface - all at once.

i do suggest try this a few times with different weight cloths on scrap wood to see what you're in for.

Any worries that paint would crack along hinge line..??

Paint will always crack if flexed. It's not a matter of if, but when. Do you have room to add wood behind the trailing edge of the wing in the aileron box? If so, do so, and use a set of dubro pinned hinges. slot the aileron, and the trailing edge, and after installing, use toothpicks through the hinge and the wood. Touch the end of the toothpicks with a drop of thin CA and sand smooth. Last, add a strip of covering material (iron on works here) to seal the aileron gap. I have used this method before where there was not enouch, "Meat", to properly install hinges. It workde well for me.

Bill, AMA 4720
WACO Brotherhood #1