20-04 Riveting Lower Wing Skins

IMG 5148

My rivet partner Tim had a week off, so this was an ideal opportunity to offer him a fun-filled few days of concentrated riveting : )

We decided to get the job done with the wings in the stands, starting on the right wing since that had the least complications.

The inner lower skins are attached first, and Vans stipulate that they are initially clecoed down to and including the J-Stiffener.

This makes it challenging to reach the rear spar rivets in some locations, and we initially gently deflected up the skins with a broom handle.

If you happen to know an Orangutan who is checked out on bucking bars, book him now!


IMG 5149

We put foam blocks underneath all riveting for obvious reasons.


IMG 5150

The rivets near the rear spar in the wing walk area had very constrained access.


Rivet Faff

IMG 5160

The following day we started on the left wing inner lower skin. All went well until I inserted a wrong rivet (too small in length) in the most awkward place … just adjacent to the inner flap bracket on the rear spar.

It had set well, but was far too flat. We had a conflab, and I stupidly decided to drill it out … after all, we’ve drilled out lots over the build and we normally ended up with a better job … hmmmm!

Well, I managed to bend the rib tab in the removal process, so ended up with 2 problems … a stuck rivet and a bent tab, with no way to bend the flipping thing back.

Don’t panic!

I made a wood wedge, and forced it up between the structure to deflect the bent tab back against the spar. After managing to get the rivet out, we attempted to set the correct size rivet.

As the gun fired, the wooden brace fell out, and the rivet had set incorrectly … OK, now I did panic!

We then went for lunch, and decided the best way forward was to use a Cherry Rivet. Even that wasn’t without stress, since I had to use a wedge to get the pop riveter onto the rivet stem against the flap bracket.

Eventually, with a sigh of relief and 3 hours spent on one rivet, we had a correctly set and strong solution. I won’t bore you with the moral of the saga!!!


IMG 5164

After this everything happily went very well.

A good light inside helped to identify rivet holes etc.


IMG 5165

Having a helper made the job pretty straightforward, but there are a LOT of rivets to set.

I admire the skill of those builders who I’ve read have done this job solo … amazing.


IMG 5166

It’s important to keep everything as stable as possible, and we resorted to a bracing plank of wood at one point to stop the wing stand moving.


IMG 5168

A mirror on a stick proved it’s worth to inspect the rivet quality as things progressed.


IMG 5173

Tim’s poor arm showing the result of being wedged inside the wing.


Pitot Tube Mast

IMG 5175

Bending the pitot tubes once inside the wing, with the very restricted access was going to be challenging, so we came up with a cunning plan.

I made a little block of wood marked with the attachment hole for the pitot tubes. I used this to bend the tubes into position prior to attaching the skin.

We had done the trials to make sure we could deflect the skin enough to locate it on the main spar with the pitot mast attached. Thing is, once the tubes are bent, they will not fit up through the mast.


IMG 5179

We did a leak check once the fittings were attached, and also I powered it up briefly to check that the thing actually worked!


IMG 5180

The skin is starting to be clecoed onto the wing in this picture, but we could still deflect the front edge of the skin up to get access for riveting …


IMG 5181

… and then when the rear rivets were all set, the skin could be gently deflected to tuck the mast lip in place.


IMG 5182

Nearly all done … Tim using the mirror to check the last few rivets.


This is a big job, and it took 5 days.

Tim won’t be volunteering for wing lower skins again : )

IMG 5183

Be the first to comment on "20-04 Riveting Lower Wing Skins"

Leave a comment

Your email address will not be published.


*