ORIGINAL: hattend
If you don't want to cut back to wood and just want a small hole patch, make it round or round the corners. Cut the hole so you have a smooth cut all around and then cut the patch to overlap the hole about 1/8 all around. Iron it down, don't use solvent.
But it looks better overall if you can cut all the way around to a wood structure and then patch the whole thing.
Don
I wish my pic would of up-loaded, it explains a lot.
I installed aileron servo's 18 inches out in each wing on the Kadet as the torque rod linkage worked loose and there was a ton of play in the aileron. When I cut into the wing I found the wing ribs were solid. Major job drilling holes in each rib, and the rib hidden under the center sheeting was more fun than one person should be allowed to have. I've already cut and replaced the covering between the servo bay and center and the 2 wing spars. Did a pretty nice job(for me) of re-covering both wing panels. I just can't bear to tear up all my work for a small one inch hole. As this is my first trainer, won at a club raffle last year to entice me back into this hobby after many, many years, I'm sure I'll have many more opportunities to re-cover this wing.
I wish I'd know about econokote before my cover job.
Thanks all for the feed back,
Bob