7.8.2 & 19 Prep bottom skins and flap brace

The instructions are starting to get very brief now and it takes more thinking ahead on my part than simply trusting the plans. A good example of this is the parts that are to be fitted to the rear spar. The instructions simply say “match drill, debur, dimple and rivet x part to the rear spar”. There are three steps where it says the same thing for the Aileron fairing, Aileron hinge brackets and flap brace.

Once I started fitting the parts to the spar it immediately becomes obvious that I shouldn’t blindly follow the instructions.

For example, the flap brace needs to be trimmed to fit. Not only is there no mention of that task in the instructions but the trim marks on the flap brace itself are wrong too. Van’s provide trim marks but if I’d have used those as a guide the end rivet hole would have been way too close to the edge. Instead I offered the part up, marked the trim line and cut. Then repeated until it was just right.

I fitted all the remaining parts and match drilled them. Then I dimpled the Aileron fairings.

That was easy enough but it was clear that I will have to rivet the parts in a very specific order or I could easily catch myself out. I think the final fitting order will be outboard Aileron hinge, Aileron fairing and then inboard hinge bracket and, finally, the flap fairing.

While prepping the flap brace I realised the instructions are simply wrong here. They say to dimple this part but I could see that wasn’t right because the flap hinge fits to it later on so it can’t be dimpled. To check I did some research on the internet and I was right to doubt the instructions. The fairing needs to be countersunk, not dimpled, so that means it needs to be match drilled to the bottom skin now. That also means I need to prep the bottom skins now and then match drill.

So after I removed the blue vinyl I deburred the holes and edges of the right inboard skin. Then I scuffed and dimpled the skin. I dimpled the skin to make sure it was a perfect fit. Then I clecod on the skin to the frame and flap brace.

Bah! The right inboard skin doesn’t cover the entire flap brace which means I’ll have to do the outboard skin as well! Grrr!

I made a start on the left inboard skin but only got half way through prepping it before it was time for dinner so I will finish it next time.

Overall a good few sessions in the shop and an important lesson learned. The instructions are more of a rough guide now. It’s up to me to think ahead and plan properly. I like that.

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