Tag Archives: dimpling

Just the right leading edge…

Some blog posts just aren’t vey exciting.  This is one of them.  Having set up the left side leading edge (with exciting stall warning vane hole and access panel!), it was time to do it all again on the right.

The right side was all cleco’d and match drilled, so it was time to disassemble, deburr, and prime.  I also pulled off the blue plastic while the skins were stiff in the jig.  This is still very time consuming, but I’m getting faster and cleaner with my soldering iron.

2016-01-02 10.37.35

I started by deburring the J-stiffener and then got to work on the ribs.  My friend the dentist dropped by to help, so while I was scrubbing the ribs with Comet, he was rinsing and drying them.  We got them all clean, dry, and primed pretty quickly.  I had a bit of a time getting the splice strips in place.  I found that by clecoing from the outside in (see below), I was able to stretch and wrap the splice strip tightly to the rib.  Then I inserted clecos from the inside out so I could gently push the splice rib into the leading edge skin.  I could then extend the clecos to grab the skin.  Then I could go from the outside (this time with the skin) back to the inside.

2016-01-02 16.30.08

Voila!  The right side is ready for rivets!

2016-01-02 17.14.27

Next up… I’ll rivet both left and right leading edges.  I’ll also get the stall warning installed.  I won’t do the final install to the spar since it will be easier to deal with the wings as parts whilst trucking them to Chicago. I’ve read several posts on riveting these sections.  Some suggest laying the leading edges flat while others suggest going in from the top (as positioned now).  I’ll figure out what works best for me when I actually get started.  I do want to make sure that I protect against dropping the bucking bar.  I would be very easy to put a massive dent in the leading edge.

I did get a new tungsten bucking bar.  This one is actually a surplus rotor balance weight from a Cobra helicopter.  It’s about a pound and a half and sits nicely in my hand.  We’ll give it a try soon!

2015-12-31 12.07.43


Turn the page…

Apologies to Bob Seger, but sometimes I feel that I get stuck on a single page for days at a time.  I can hardly wait to turn the page, as it were.

This time, the page is 10-14.



It took some work to get to the page, but then it seemed like I was just stuck there.

As of the last writing, I was working on the bulkheads and looking ahead to this page.  It seemed so easy!  It turned out to be a lot of work!

The parts are getting very large.  This means it takes proportionately longer to deburr, dimple, and prime things.

First up was the bottom skin.

I pulled the blue plastic off (very hard with the cold temps).  I had to wipe off some adhesive like crud from where I pulled riveting strips off the bottom with acetone.

I deburred the edges (the inner edge is a kind of built in j-channel) with file and sandpaper and scotchbrite. Then I started dimpling… and dimpling… and dimpling!

2014-12-12 10.27.44

I got a “selfie” while I was at it so the FAA will know that it was me freezing my ass off building this thing.

2014-12-12 10.28.02

I primed and then painted the inside skin pan Rustoleum Granite grey.  My thinking is that the interior is “public” space.  It will be viewable, stuff will knock around in it.  The primer isn’t super durable (and not really a final finish), so I topped it with a nice neutral grey.  It looks nice!

2014-12-12 11.30.09

Van’s recommends using two sawhorses, but I found it easier to work with one sawhorse and one table end.  I could clamp the bellcrank rib box to the sawhorse and make it very stable.

2014-12-12 14.08.59

I decided to back rivet the bottom skin.  I had a two pound back rivet bucking bar that I was planning on using for the wing skins.  It worked really great here.

2014-12-12 14.27.35

You can get nearly every rivet this way except for a few that are right up against the bulkheads.  I only had to buck four rivets.

2014-12-12 15.11.592014-12-12 17.10.42

The riveting went really fast when my son stopped by the shop to give me a hand  He would pull a cleco, drop in a rivet, and place the bucking bar.  Then I would give the rivet a tap.  Super-easy.

2014-12-12 17.10.26

I came back the next morning, bucked the four missing rivets and started on page 10-14….

2014-12-12 16.40.58

There are SO many rivet holes everywhere!  Four stiffenners, two longerons, and matching holes in the left and right skins!

2014-12-12 11.51.45

The side skins have a lot of detail bits to get to.  Here, I’m going at the rudder cable pass through opening with a small file.

2014-12-13 10.57.18

Finally, the right skin get’s a coat of granite grey to finish it.

2014-12-13 18.09.34

After this skin dried, I hung it on the bottom skin. Then I had to start all over again with the left skin!  I was much faster the second time around though.

Over the weekend, I was going through the plans errata at VansAirForce and noticed that the instructions forget to mention to rivet the bellcrank ribs to the F-01407 bulkhead.  Sure enough, I hadn’t done it.  I flipped the rear fuselage over and was able to squeeze four of the six rivets, but had to use my offset set to drive the last two.  The shop towel helped protect the finish from the bucking bar and the blue painters tape did the same for the rivet set.

2014-12-15 10.50.56

The stiffeners and longerons go on in this step.  The spar is too heavy a gauge to dimple, so it has to be countersunk.  There are 176 holes or so.  I had a lot of magic pixie dust!

2014-12-15 15.53.53

The stiffeners and longerons are supposed to “slide” in… ha ha ha. I ended up having to put them on before clecoing the skin in place.

2014-12-15 17.34.57

I eventually managed to get everything in place and flipped it right side up on my tables!

2014-12-15 18.31.03

It looks practically ready to rivet!  It’s not… still a couple of pages to go before that happens, but at least I can finally turn the page on 10-14!

So page 10-15 just has you cut some tabs off of the aft bottom skin.  It is actually a lot of work because you have to rebuild a smooth edge from the rough saw cut.  I ended up clamping it loosely to my bench and filing the edge down to a smooth finish (and then doing a final pass on the scotchbrite wheel).  I gave it a quick coat of primer and granite grey and re-clamped it to the bench to rivet the rearmost bulkhead.

2014-12-16 13.15.01

The most exciting news was that I took the last few items out of the empennage case.  I needed the space to walk around the table and wanted to tip it out of the way.  So I took out the top skins  and a couple miscellaneous parts and tipped the box on it’s side.  I must really be getting to the end of this kit!

2014-12-16 12.47.37

I had a hard time getting the aft rear skin and bulkheads in clecoed in place.  I ended up pulling the skins off and rejiggering the hole mess.  Eventually though everything was square and then the clecos slid right in the way they’re supposed to.  My son stopped by to help rivet, but we spend about an hour just getting the clecos ready.

We were able to squeeze the top row.  It went really fast because we could squeeze most of the rivets away from the bulkheads.  My son would pull the clecos and set up a rivet for the easy ones. I got the reset with my tungsten bucking bar and mushroom set.

2014-12-16 15.18.072014-12-16 15.17.49

It was getting late, so I didn’t have much time (my son had gone home to sit down and warm up since it was back to a one person riveting operation).  I got the top half of bulkhead rivets done down to the A stiffener.  I’ll get the bottom half tomorrow… I’ll probably need some help to get the curved bottom parts though.  The skins there do not lay very flat.  I broken them as Van’s suggests, but they really need a lot more bend than I gave them (particularly  in the aft section).  I’ll probably try to soft tap them with my rivet gun to set a curve.


2014-12-16 17.44.34


Got a few hundred rivets in today.  Should get about three hundred more tomorrow!  Then the top skins go on with a dozen nut plates and the wiring harnesses get routed (the harnesses are already in place to get them to run through the stiffener channels but have to be finalized in a couple of pages).

Closing in on a new trophy if I can just get off page 10-19 🙂

Bulkheads everywhere….

Even with mass this morning and fixing the Christmas lights, I got to the shop by 1:30 for about 5 hours of work on the bulkheads.

There are five bulkheads.  I riveted the aft-most one yesterday and deburred and primed the next two  Those came together pretty quickly.  With lots of cold 1/8″ rivets, it was easier to hand squeeze than to use the pneumatic squeezer (better control and more oomph by hand!).



I clamped my hand squeezer to the table which made the riveting much easier than holding an unweildy bulkhead and a rivet and a squeezer all at once.  It also made it a lot easier to get a good push on the arm and make best use of its mechanical advantage.


The rear three bulkheads take up only 20″ of the fuselage!  They have bulky straps to hold the vertical and horizontal stabilizers in place.


The next steps seemed so simple…  The 2 forward bulkheads only have a few rivets and no thick aluminum straps to mount.  However, they are very large (compared to the other bulkheads), are made in two pieces, and have many, many nooks and crannies to deburr.  I filed the worst parts of the outside with a fine file, hit the many lightening and system holes with sandpaper and scotchbrite, and sanded around each of the approximately 10,000 flange tabs.  Then I finished the accessible edges on the scotchbrite wheel.  I used almost (but not quite) all my remaining primer priming the bulkhead parts.  Not too many rivets to do and the squeezer was still set up, so I thought I would bang together the last two bulkheads.  The first one went together very quickly (only 5 rivets as you leave the top 3 open for later riveting).  The second one has ten rivets (an extra two hold the rudder cable bracket to the bulkhead).   On my very last rivet, the squeezer apparently shifted so I got a smile rivet to drill out next time.

2014-12-07 18.04.16

So, the bulkheads are done for now.

2014-12-07 18.03.50 2014-12-07 18.04.02

The next steps are to deburr and prime the bellcrank ribs and one more, thankfully small, bulkhead.  Then the bottom skin goes on and it starts to look like a real airplane body.


Dis-assemble, deburr, dimple, and prime (rinse lather repeat)


Rivet count: 1819 + 0 new = 1819

I had a half day to work on the plane, so I jumped back into the elevator.  After finishing the initial assembly and match drilling, it was time to take it all apart to prep for final assembly.  I finished getting the blue plastic off the left top skin.  I finished some of the holes and polished the edges.  I also “broke” the trailing edge and the rolled leading edge so that they would sit flatter after riveting.

Then it was on to dimpling.  The DRDT-2 is really nice for this.  The table is big enough to hold most of the skin and then I can pull the lever one handed to set the dimple.2014-08-03 13.45.09

This worked fine until I got the the trailing edge.  The instructions warn that normal dimple dies will compress the slight bend.  So they ask you to grind down an old/cheap dimple to fit.  As luck would have it, I had a dimple die that was sticking, so I bought a nice new one from Cleaveland Tools.  I took the old one, cleaned up the pilot, and used a belt sander to grind down one edge.  This went into the DRDT-2.  Then I just had to watch the die orientation so that the ground down part was facing forward.  Hard to see in the photo, but the ground down part stays inside the crease.

2014-08-03 14.05.582014-08-03 14.05.58

I also had to countersink (part of) the rear spar.  The trim tab hinge needs to lay flat under the spar flange.  So, you cleco it in place and countersink the top.  I think you cleco the hinge in so that you countersink into the hinge piece if you go too deep.  I found that even with a deep countersink (enough to hold a rivet just below the surface), the top of the hinge was unmarred.  Clecoing the hinge piece does insure that you don’t countersink more of the spar though!  The other holes are just dimpled.  The instructions indicate that you should grind out/modify one of your squeezer yokes just to get it to fit inside the small, slanted spar.  I think that was total overkill.  You could use a pop-rivet dimple die or use a different squeezer.  I used the vice-grip dimpler I used to dimple rib flanges.  It fit fine and made short work of the holes.2014-08-03 16.38.04

There are many more small parts to get here.  I finished the top skin, the root and tip rib assemblies, all of the ribs, the mounting plate for the trim motor, the sheer clips, the gussets and the rear spar.  I still have to countersink the trailing edge piece and the larger front spar.  I also haven’t even touched the bottom skin!  Sigh.

2014-08-03 18.08.49

So I probably have another day’s work to finish the left elevator and do the right one.  The right one is a little easier (one fewer sheer clip, no trim tab, no trim tab mounting bracket), so hopefully I’ll get all those done soon.  Then it’s off to the rivet races again for the 1154 rivets in the elevators and trim tab.