C/S vs Dimple

[andrewbutler]

Hi,

I am in the process of preparing my RV7 "canoe" for priming and riveting. The plans to say review section 5E and diagram 5-4. This refers to countersinking sandwiched (in particular .032) skin. There are several placed in the the canoe where skin is sandwiced so can anyone give advise on the below three sections:

1. The front 772 lower skin. Would it be better to dimple the top skin, cs the second and leave the longeron underneath ountouched.#
2. The aft skin has two rows of holes where it connects to the centre section. What about C/S ing the forward row of holes on the sandwiched skin, leaving the underlying 706 bulkhead alone and finally
3. The main longeron has two skins above it. Should I simply countersink the sandwiched skin that lies against the longeron and leave the longeron untouched.

Common practise appears to be dimple all the skins and c/s the longeron, even though the plans imply that it is okay to c/s sandwiched skin........

Others any thoughts?

Andrew Butler
RV 71700
Galway, Ireland.

 

[lorne green]

c/s, dimpling

Sounds like you're on the right track. Keep on pounding those rivets. (after you've dimpled of course)

 

[WildThing]

Dimple (or not)

Hey Andrew,

Van's say's any combo is OK. Dimpling is the strongest though, as the dimples all "nest" and the joint doesn't rely on the rivet only.

I'm dimpling everything on my -8A (though I like the looks of CS better) Go figure.

 

[wingtime]

any way you like

I belive I dimpled the aft two rows of the forward bottom skin. Then I dimpled a piece of scrap that was the same thickness to use a countersink template. I then countersunk the center bottom skin while it was clecoed to the center section. The countersink actually nested into the center section slightly. I flet this was stronger than countersinking the center section for a full dimple.