LH Flap – Prep and Assembly

As I near the end of dealing with fitting skins to structure, my confidence was pretty high that this would go well for the flaps (and eventually the ailerons). I’ve learned important lessons about how to inspect skins for proper fabrication – especially bends.

As I discovered from the building the empennage, lengthwise bends (folds) of the skins must be very close to perfect or else entire structure will be pulled out of true alignment when preparing or attempting to close up the final assembly.

There has proven to be considerable lead time in the process of securing replacement parts and the earlier a problem is discovered, the better. Almost immediately after the main QB kit was delivered in February, I looked over the flap and aileron skins – very carefully – and determined that they’d likely be acceptable.

Outdoors metal preparation with Alumiprep 33, Alodine 1201 and then rattle-can primer is much more convenient and pleasant with the warm summer weather. I opted to use NAPA 7220 gray self-etching primer, as none of the surfaces would be exposed. I had the stuff on-hand, but find that I don’t like it as well as the Rust-Oleum product, if for no other reason than the performance of the spray can. The any-angle can from Rust-Oleum is superior, even though I paid considerably more for the 7220 primer. (As I’ve mentioned before, if I do another build, I may well forgo alodine and primer altogether. With my budget and facilities it has been a huge time sink and perhaps not worth the effort. Even at my tender young age, I’ll be pushing up daisies before corrosion would be an issue with an untreated airframe.)

Due to a shortcoming with the listed shipping quantity in the wing kit packing list (KPL), I received only enough 4.8 x 15mm rivets to assemble one flap. I also found that one-size-fits-all — didn’t. It turns out that the overall thickness of one parts stack-up was very slightly less than the recommended grip length of the 15mm rivets. Even though there was no mention of this issue in the assembly instructions, it became obvious that a 10mm length would be better.

I ordered more rivets – both 15mm and 10mm lengths – twice. Once from TAF USA and then from a supplier of Gesipa rivets in UK. TAF sent a big batch of 10 and 15mm rivets to me overnight. Bravo! Great support effort! Thank you!! But, the rivets were not to my liking. They are some alternate brand, different design, slightly larger diameter (didn’t fit) and not nearly as well finished as the Gesipa product. I ordered the real deal, but it took 2 weeks to get them in-hand.