Countersink or not. The VS rear spar flange, the lower rivet holes, below the skin, plans state you use AN 470 rivets. A neighbor who built a RV10 recommends countersinking and using the 426's for the hole below the skin. He said you have better shear strength. I called Vans are their technician said stay with the plans. Has anyone countersunk those holes. What are your recommendations.
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Riveting VS rear spar
- Thread starter togaflyer
- Start date
mvidalr
Well Known Member
VS rear spar countersink question..
The plans (RV-14) call for countersinking the VS rear spar doubler to attach it to the (dimpled) rear spar. As a first-time builder I'm trying to get the correct countersink depth on the rear spar doubler. I'm practicing on scrap Aluminum.
When I use the manual's instructions on countersink depth (7 clicks beyond the flush rivet-head depth) and test fit the dimple into the countersink, the dimple is a long way from being fully into the countersink. When I put the rivet in and set it, then hold up the pieces to the light, there's still a small gap between the 2 sheets, the countersink is just too shallow to absorb the dimple. In fact, it's obvious that the amount of material in the dimple won't all fit into the small countersink volume, and the dimple material which won't be absorbed into the countersink will just serve to push the 2 surfaces apart. Again, as a first-time builder, excuse my ignorance, but I want to be sure the 2 surfaces are in good contact, which would seem a strict requirement for structural reasons.
What am I missing?
PS When I fit 2 dimpled surfaces together, the dimples still don't nest completely, but the riveting process seems to cinch things up nicely, not so in the countersink case.
The plans (RV-14) call for countersinking the VS rear spar doubler to attach it to the (dimpled) rear spar. As a first-time builder I'm trying to get the correct countersink depth on the rear spar doubler. I'm practicing on scrap Aluminum.
When I use the manual's instructions on countersink depth (7 clicks beyond the flush rivet-head depth) and test fit the dimple into the countersink, the dimple is a long way from being fully into the countersink. When I put the rivet in and set it, then hold up the pieces to the light, there's still a small gap between the 2 sheets, the countersink is just too shallow to absorb the dimple. In fact, it's obvious that the amount of material in the dimple won't all fit into the small countersink volume, and the dimple material which won't be absorbed into the countersink will just serve to push the 2 surfaces apart. Again, as a first-time builder, excuse my ignorance, but I want to be sure the 2 surfaces are in good contact, which would seem a strict requirement for structural reasons.
What am I missing?
PS When I fit 2 dimpled surfaces together, the dimples still don't nest completely, but the riveting process seems to cinch things up nicely, not so in the countersink case.
