Dimpling -7 Flap Piano hinge & flap Brace / Gap Seal?

Hey guys-
I'm running into one of those scenarios where I kind of don't like the process outlined in the plans... (Almost like the lesson I learned looking back after the "per-plans" process was done & wishing I had done it another way... An example, would be if I had it to do over again, I would have dimpled the fuel tank rear baffle to skin joint rather than countersinking the skin.)

Now, my current dilemma is attaching the flaps. Should I dipple the skin, hinge material & the gap seal / flap brace... Or just go by the plans & kick myself later for countersinking the hinge. Any clearance issues you can see with all dimpled materials?

Thank guys!!!!

IIRC, the plans call for dimpling the bottom skin, countersinking the flap brace, and only drilling the hinge. When I was doing mine, I found LOTS on this subject in the forums and consensus seemed to be just to do it per the plans. Dimpling the hinge tends to distort it, and countersinking it generates knife-edged holes possibly compromising the strength.

After you drill the hinge to the brace and skin, you can use the hinge holes to pilot the countersink for the brace.

I`m dimpling mine. I did on the trim tab as well with no issues using a hand squeeze. Very little distortion of the hinge if you go easy by hand.
I`ve seen people use a pnuematic squeezer closed up tight and it WILL destroy the hinge peice.

Here is exactly why I don't want to counter sink the flap brace per the plans. Take a look at the depth and diameter of the of the counter sink in the main spar to accommodate the .030 inboard skin... the flap brace will most definitely be knife edge after counter stinking I kinada like the method used on the rear spar... dimple & then hit it with a deburr bit to create a better fit for the skin.. I don't see any clearance issues if this same technique was used on the flap brace and hinge material. At least I'm not left a knife edge... I'm sure it fine either way.. please keep the comments coming!!!

I did mine per plans, I dimpled a scrap piece of hinge and the distortion was more than I could tolerate.

Don't know of an RV yet that has lost a flap!

When in doubt, consider following the plans.

Since the brace is sandwiched between the skin and the hinge, it doesn't matter much that there may be a knife edge, as long as the machine countersink is of a depth that the skin dimple is still a snug fit into it. What are there, 8,000+ working examples in the air now? Did mine per the plans, looks fine and is quite rigid.

Daniel,
It works fine per the instructions. You have a lot of rivets holding it in place and the machine countersink on the flap hinge does not have to be really deep. I too tried to dimple a small section a long time ago but buy the time you get 4 or 5 dimples into a hinge it starts bowing and it will cause waves that will make it harder to put the pin in later.
Smilin' Jack

if you're worried about knife-edged holes

as stated above, this is a sandwiched assembly, the knife-edged flap brace is between the skin and the hinge.

If the thought of the knife-edged material is worrisome enough, use some proseal between all of the pieces-- howevever then I'd be more worried about serviceability down the road, but you pick your poison.

Thanks all. I'm not worried about things falling off or the knife edge sandwich. I've worked on flight school planes and seen some real crapolla... just wanted some outside opinions. I tend to over think sometimes and wanted some other opinions. gracias all!!!