Originally Posted by
scale only 4 me
Mounting really isn't much of an issue as long as you have access to the bottom of the fuse to add a rear mounting location
Between those two, I'd lean towards the Stinson over the Decathlon, I've had bad experiences with float plane with full symmetrical airfoils and high wingloading adding floats creates
I Built a Great Planes Decathlon back in the days,, it didn't end well,,, I added a float to a Extra 230,,, the was a fail also
good luck
I believe your issue with fully symetrical may be one simply of incidences. Determine your thrust line and set it at zero for reference. For a flat bottom wing your stab and the top of the floats should both be at zero degrees as well. The wing should be 1-2 degrees positive for a flat bottom. I suspect that for a symetrical you may need to add 1-2 degrees more for a total of 2-4 deg. Not ideal for a symetrical but............. Thrust line and floats should be at the same incidence. A positive thrust line will cause the floats to dig into the water. Not good. Ditto for negative wing incidence.
For the OP: Outer Zone plans service has a handful of float plans available for a free download. My preference would be to use either of the first two,the 33" from GS Scale Products or the 36" set from Flying Models. Both are basically Edo floats and can be easily resized to fit any model. Link:
Outer Zone