Rudder Dipmle and Prime

After match drilling the skins of the Rudder, I can now prepare for priming the Rudder parts. The first step is dimpling the skins, spar and ribs. Many builders do this step after priming, but I rather do it before.

Again the DRDT-2 is invaluable for this task (although quite expensive). After dimpling there remains this specific task of fitting the counter balance weight in the Rudder. Both the Rudder and the Elevators have a counter balance weight to make the controls smoother. It took a considerable time to find the correct nuts, washers and bolts. I used the shipping list to find the correct bag.

To set the rivets flush with the skin, the skin needs to be dimpled, because it is so thin. The trailing edge strip cannot be dimpled, because it needs te sit flush on both sides. Fortunately this strip is thick enough to countersink. This means drill (with a large drill) until the rivet sits flush.

You can also countersink ribs if they are thick enough, however I like dimpling better and it is stronger. Countersinking does reduce weight, but that is negligible.

Last step before priming is degreasing the parts. I don’t scuff the parts, because during tests I found that the etching primer bonds perfectly on Alclad when grease-free.

During degreasing I discovered that I forget one rib to dimple. Also the end of this rib is very thin, leaving no room for the squeezer. The alternative is manual dimpling with pliers.

Every time when I prime, I get better in using the spray paint gun, but still I’m not entirely satisfied with the result. It’s ok, but not something that makes me proud. I figure that after completion of the plane, I’ll be an expert.

In the afternoon, there was some time left to start assembling the spar of the Rudder. Again a lot of searching through the bags to find the correct nuts and bolts. It would be great if Van’s delivered the bags per component, but with some logic it is doable even for Europeans.

Time: 6 Hours, Rivets: 37/2


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