double flush rivets?

[prkaye]

For the training project, the rivets along the trailing edge skins, through the trailing edge wedge, are supposed to be AD3-3 rivets. These barely make it through all the material. The instructions say they should be "double flush", which I guess makes sense, because when I back-rivet these short rivets through the trailing edge, the shop head is very small,and basically flush with the skin.
My concern is that I can't imagine there will be much/any strength in these rivets... have I misunderstood something?

[robertahegy]

The length rivet used to double flush should be sufficiently long to fill (or nearly fill) in the dimpled and/or countersunk area. You are, in affect, creating a flush head rivet shop head by slowly working the rivet into shape. It is a slow, deliberate process that may require some practice before you rivet trailing edges with the AEX wedge. Combinations of flush set and backriveting are usually necessary.

Roberta

Below are examples of MFG flush heads (black line) and flush shop heads (red line). Care in shooting these will result in nice, flat, shop heads that will nearly look like MFG flush heads.

[RV7ator]

Nope, you haven't.

Instead of a 1 1/2 diameter unbucked protrusion, a rivet destined for double flush is about 1 diameter proud of the shop head surface. If any longer, the shop head won't be contained within the dimple/c'sink.

John Siebold

[G-force]

Thats how they shold look, like it didnt fill the countersink all the way on the shop head side. The tricky thing here is getting them all set without putting a big bow in the trailing edge.

[mike crowe]

The rivets for the trailing edge are AN426AD3-3.5 the 3-3 are for the stiffers

[prkaye]

the plans for the practice project said to use a flat (mushroom) rivet set. What does "mushroom" refer to here?

[Rick S.]

Mushroom refers to the shape of the rivet set, also called a flat set but if you look from the side it looks like a mushroom. There is a slight parabolic shape to the surface, not quite flat. Just use your normal flush riveting set, you'lll be fine.