Elevators finished

Even the 31 drill is too small for the dimple die. Drill up all the holes to 30 and dimpled. A few stems protruded maybe 1/10 of a mm or less, which was easy to fix with a scothbrite wheel on a drill. So I think I continue with 30 drill bits for now. Also drilled the hinges on the H-stab.

Sonex will send new parts for the defect vertical stab parts.

Drilled elevator skins

The 31 and 32 drill bits came today from Aircraft Tool Supply. The 31 drill bit works, but the 32 drill bit is nonsense. It is nonsense because the hole becomes too small for a cleco. Although it is possible to push a cleco in there by force, you don't want to do that because you will damage the skin. The cleco itself does not work properly when the hole is too small, the friction will be so large that the spring does not engage, so the cleco does not clamp the pieces together. I haven't tried the dimple dies, but I would guess also the 32 holes are too small for the dies.

Vertical tail

Deburred the vertical tail parts. Discovered that 2 ribs were defect, flanges were bent offset the center by several mm. The main spar channel was also a bit off center. Very irritating, if the Sonex people had just looked at them - once - before packing them they would have seen it. Tried to put the skin on, and somehow it fits.

H-stab riveted

Got my new #30 drill bits on Saturday, drilled up the H-stab skeleton and riveted it together (still waiting for the 31 and 32 drill bits to be used on the skins). I know there is really no need to prime the internals of 6061 aluminium, but I just can't resist the urge to prime... Primed the thick parts with an aluminium primer from Duplicolor. That primer really feels nice, with a smooth and hard surface even though it is only 1K. Then I primed the mating surfaces using a brush and Jotun Yachting Vinyl Primer. That primer is supposed to be watertight and good, but the resulting finish wasn't all that good, it became thick and spotty.

The plan is to polish the airframe and use some color on the fiber glass parts and some of the aluminium. I would really like to use Jotun Yachting products, since they are available everywhere and they have this new system with high gloss 2K paint that that can be rolled on and is extremely durable. But the experience with the primer was not good, it probably has to be very thick to give a good finish, and then it becomes very heavy. Jotun also have a 2K epoxy primer, but then I am better off using my real aviation 2K Strontium primer (and that is just too much work and hazzle). Duplicolor automotive spray cans seem to be a better alternative right now, but will that paint last? Then I probably can use Biltema automotive paint at half the price (Biltema use some OEM paint from an unknown, but large supplier similar to Motip-Duplo). Both Biltema and Duplicolor is readily available and they have primers for plastic, steel and aluminium to be used under their color system.

Also tried my Duralac. Each rivet has to be dipped in that yellow high viscous stuff. Actually it's not that much work, because when dipped I can insert lots of rivets at the same time, they stay in place due to the viscosity. After that I just go over with my pneumatic rivet puller. For the external surfaces this yellow goo will not look nice, but the excess Duralac can be wiped off easily with paper and acetone, and still seal and protect the rivet and aluminium internally.

Rudder

Started cutting the rudder and drilling holes for the ribs.

Tips fixed

Some "blue foam", epoxy, glass fiber threads and gel coat and the tips looks perfect again, and the skin fits as it should.

H-stab and tips

The tips were a bit challenging. For some odd reason, the tip ribs have pre-drilled holes. So do the skin, but not the tip. The tip is to be sandwiched between the rib and the skin and this makes it impossible to line up the holes. I used my old home made hole duplicator and duplicated the holes from the rib to the tip. Then with the tip in place, the skin were way to tight and I had to cut off a bit of the tip to be able to line up the holes. This leaves a small gap I need to close with foam or something glued to the fiber glass tip.