Updrilling of Sonex tail skins

[sonex1678]

I have cleco'd together the complete vert stab assembly to include the skins to ensure everything lined up properly. I was wondering if I could just proceed with the up-drilling with everything together, or if it was better to up-drill the structural components together first (spars, ribs, etc) debur, prime, rivet: and then reinstall the skins and updrill them separately?

Thanks

Doug

[NWade]

I personally always rivet the main structure of each item together first, before I up-drill the skins. I just found that its easier to keep the structure from getting any twist/warp if the "skeleton" is riveted solidly. Clecos to a pretty good job of holding things; but there will always be a little bit of slop/room-for-movement when they are pinning components together.

But that's just my two cents!

--Noel
Sonex #1339
Taildragger, Center-stick, Acro-Aileron, All-flush-rivet, Turbo Aerovee
Empennage complete, RH wing complete, LH wing-skins about to be riveted.

[Bryan Cotton]

I'm with Noel, but you could updrill everything with just clecoes involved. Not sure what it buys you in this case.

[Rynoth]

Question would be this: are there any holes that you ccannot updrill/rivet without first removing the skins? If you have to remove the skin to get to certain holes on the substructure, you run the risk of the substructure shifting and being of different alignment once you put the skins back on. By drilling and riveting the substructure first, you avoid this potential issue. I'm also guessing that the plans say to complete the substructure (including rivets) prior to skinning, and keeping with the plans is a good rule of thumb.

[sonex1678]

I suspected that the best approach was to complete the main structure first, then move on to the skins, pretty much for the reasons mentioned. I had noticed that it had been done all at once by several builders after reviewing their builders web pages, and had thought that doing it all at once would save some time by avoiding multiple stages of disassembly/reassembly and priming, but after your responses, I will take the time to assemble in multiple stages, completing the main structure first--a little more time spent now might save a lot of time down the road. Thanks for the help.

Doug