Category: Leading Edge

Richard popped over again today and helped get the right leading edge ribs riveted to the spar today. Just like the previous post where we worked on the left leading edge this job is impossible to do alone. The person bucking needs to get their arms deep inside the leading edge.

We also managed to fix the bad hole that was a result of drilling out the bad rivet. We drilled the hole to 5/32 using a #21 drill bit which tidied up the hole very nicely. While discussing which pop rivet to purchase I remembered that I might have some AN470AD5 rivets in my supplies. I checked and sure enough I did though they were longer than we needed. I used my rivet cutter to cut them down to size and Richard and I bucked the rivet which worked great. Very pleased with the result.

With that done I can update my little diagram and colour another section green. Yay!

Earlier today (see my previous post) I did a bunch of fuel tank work. After lunch my buddy Richard popped over to help me get the leading edge ribs riveted to the main spar. I had already done the outboard most rib using a hand squeezer on Thursday night but the other 5 ribs were going to be impossible to do alone because the gun needs two hands and the bucking bar needs a contortionist!

I’d already read a whole ton of builders logs and prepared myself for this moment. For example, I knew that I needed to use the double offset rivet set and that it still wouldn’t fit without grinding it down. So I did all that last week. Once Richard arrived we got cracking on the left wing leading edge riveting. Richard was in charge of the rivet gun mainly because his arms were too short to reach in the depths of the leading edge assembly.

In no time at all we had managed to get all of the left leading edge done. It felt great to have finally finished the left leading edge.

We made a start on the right leading edge to spar riveting too and after riveting the middle rib and most of the 2nd rib we had our first bad rivet! I quickly drilled it out and we re-shot another rivet but that too went bad! We think there might be something amiss with the rivet set. Out of time, Richard had to leave so, after he left, I drilled out the rivet a second time. Unfortunately the drill slipped and made a right mess of the rivet hole. I used my cheap Amazon bore-scope to take a closer look at the damage from inside the leading edge. The aft side of the spar looks OK but the forward side looks like this.

I’ve thought long and hard about how to fix this since then but I will definitely need to speak to my inspector before making any decisions. I think I will have to enlarge the hole to a -5 size and then use a pop rivet here, MSP-54 i think. Those MSP pop rivets are made by Cherry and are almost as strong as solid rivets. Unfortunately I can’t use a -5 solid rivet here as there is no way that the rivet set will fit on the rivet of that size even if I grind it down to its bare minimum.

Ah, the joys of building an RV!

I got my bi-annual medical renewed today which was no big deal other than it must be every 2 years now due to my age!

Feeling chuffed I thought I would mow the lawn before dinner. Shortly after starting the mower it coughed and cut out. Hmm, out of fuel probably so I poured more in only to watch it pour out the bottom of the fuel tank! Closer inspection showed me that the fuel pipe has split.

To fix the mower I popped into the workshop to look for some tubing that would do the job. I couldn’t find any but I did see the rivet squeezer sitting tantalisingly on the floor under the right wing.

That was it, I got distracted. So I sat on the mechanics stool and began to roll backwards while holding a pot full of rivets. Unfortunately the wheels of the stool caught on something and threw me backwards and onto the floor. Seconds later the rivets landed all around me too!!!

Talk about bad luck! I was ready to give up but picking up all the rivets calmed me down and so I thought I’d squeeze a few rivets anyway.

Before I knew it I had the entire skin of the right leading edge riveted to the main spar and with only minutes to spare before going out for dinner.

I must have used up my bad luck for the day in one go as the rest of the evening went without a hitch.

Today was one of those days. It started with me dithering about whether I should do some work of wether I should just chill indoors instead. I told myself doing something is better for the project than doing nothing so off I went up to the workshop. My plan is to repeat everything I did on the left wing structure on the right wing.

Four and a half hours later and the right wing structure is now at the same stage as the left wing; countersunk, dimpled and primed. No pictures of this as it really is identical to the left wing.

Once that was done I decided to rivet the left leading edge skin to the left wing main spar.

Wow, that’s the first major assembly permanently fitted to the wing. It looks fantastic without any cleco clamps holding it together. It still needs the internal ribs riveting to the spar as well but I need a hand doing this as some of the rivets are really difficult to reach.

While quality checking my handy work I spotted a minor error in my previous work. Somehow, one of the bolts holding the tie down bracket on is too short! I’ll need to replace it before closing the wing. I’m so glad I spotted this before the wing got closed up permanently!

Lastly I decided to JC5A the right leading edge and cleco that to the right tank. I like to leave parts like this for a few days to let them settle before I rivet them, I think they do move a bit with expansion and contraction as the temperature changes overnight.

That’s it! 6 hours of mundane repetitive work. Not the most fun day in the workshop but at least it’s better than doing nothing!

It’s Sunday so I considerately waited until 10am before I fired up the compressor and rivet gun. I hope my neighbours appreciate it! I enjoyed riveting today, it’s great to see things going together after so much prep work.

The left leading edge assembly also houses the stall warner. This is not in the plans or instructions as the original Van’s aircraft didn’t have them. Instead it is supplied as an optional kit. Even though I’m having an AoA I decided to fit the stall warner any way. However as soon as I reached the point of riveting this I found the electronics get in the way of the bucking bar, doh! No big deal, I unscrewed the electronics and finished riveting.

Once all the riveting was done I adjusted the stall warner as per the instructions so that it triggered with minimal movement.

Next I reviewed the instructions and it was time to deal with the pitot. Van’s pitot is simply a piece of 1/4” tube bent to an L shape and fitted to the leading edge. I didn’t like that for a couple of reasons. One, it’s too fragile and, two, I want an AoA (Angle of Attack). As I’m fitting Garmin electronics, I decided to use their pitot/AoA but this device needs to be fitted to a mast. After some research I found the SafeAir to be the best for this job. All this research was done last year some time so all I needed to do was find the mast I’d bought. Luckily I’m a semi organised person and found it fairly quickly.

I read the instructions and researched build logs before making a start. To fit this part I need to cut a hole in the bottom wing skins just outboard of the last inspection panel. Scary! Finally I decided on a location for the pitot mast being one rivet away from the rib nearest the access panel. A friend of mine fitted his there too so it seemed logical to follow suite.

Next I drew the outline on the skin using the paper template and then drilled the skin with a uni bit.

Using my dremel and various files I opened up the hole to the same shape as the template. After careful drilling, filing and sanding I finally offered up the mast to see if it would fit. Nope! Not even close! What?! How could this be? I checked the template that came with the kit and it was obvious what was wrong. The template was a photocopy and had not been copied to scale!!! Well, at least it was smaller rather than larger. Enlarging the hole freehand was not a a good idea so I made another template using the mast as a guide and fitted it over the top of the hole i had already made. I then enlarged to that template. A couple of adjustments later and the mast finally fits.

I’m quite pleased with the result. I will probably fill the very small discrepancies with body filler if I think it needs it. It may not.

Next was to do a major tidy up of the workshop. I try and keep it tidy as I go but this week lots of tools didn’t get put back. Now that’s done both leading edges and both fuel tanks are ready for inspection when my inspector returns from his holiday.

Today I woke bright and early and couldn’t wait to start the weekend by assembling the leading edges.

The work started by first dimpling the nutplates and then covering them in JC5A jointing compound. Once that was done they were cleco’d to the tank attach jointing plate and riveted in place. As soon as I tried to set the first rivet I realised I needed a third hand to hold the work piece. I popped it in the vice and that did the job nicely. 10 minutes later all the nutplates were riveted in place.

Next was to JC5A the flanges of the first rib and then Cleko it to the top side of the l/e skin. I repeated this process until all the ribs were in place.

Once all the ribs were cleco’d every other hole to the top I then gently laid the assembly in the wooden frame that I built the fuel tanks in. Then I cleco’d every other hole starting from the aft holes and working forward. The assembly soon nestled in place nicely.

Once both leading edge assemblies were complete I riveted the stall warner access plate in place using the hand squeezer. I also disassembled the stall Warner and torqued any nuts there. I checked the operation then reassembled with JC5A compound and cleco’d it to the left skin.

I then set up the rivet gun and compressor. I went ahead and riveted all the rivets in the right leading edge. This was surprisingly tiring but I got it all done with only two rivets drilled out and replaced.

I didn’t have time or energy to do the left riveting so I called it a day. I couldn’t resist sitting it in place as I left the workshop though. Looks great riveted and no clecos holding it together.

It’s been a long time since I last did any spray painting so I was a little apprehensive about this. So first I did a little refresher research. I found this very useful guide for making sure the spray gun was correctly set up…

Once the gun was set up and ready to go I setup a table and the hanger ready to hold the parts while I sprayed them.

Next i mixed 500ml of PR30B wash primer. Once it had sat long enough as per the instructions I poured it into the spray gun via a filter. I was ready to go so I donned my paper suite and face mask and sprayed the parts. I forgot how much wash primer runs. Not a problem but I’m sure I can do better next time.

While the wash primer was drying I mixed up some coffee and then some PR143 epoxy primer. It didn’t take long to prime the parts with the top coat primer and they were soon hanging up in the workshop drying (curing?). That’s it for today, nothing more can be done until these items are dry.

Skins are stood on some 2×4 blocks to let them dry.

Not a bad session, except that one of the skins fell into the other and the primer has rubbed off. No big deal I have some spray can primer that I can use when it’s dry if need be.

Before primer can be sprayed I believe it’s a good idea to give all the surfaces a jolly good clean. They’ve already been scuffed in previous session so the purpose of washing the parts is to remove all the aluminium dust and finger grease from the parts. By being clean that helps the primer bond with the surface and, hopefully, prevent any areas of poor adhesion.

First I clean the metal with standard paint thinners and a rag to remove as much of the aluminium dust as possible. Next I use Polyfiber 310 aircraft cleaner from Aircraft Coverings with a green scotchbrite pad to properly wash everything. I like the Polyfiber 310 because it is an Alkaline cleaner that really makes the aluminium visibly clean.

These parts have been cleaned and are hanging out to dry before priming tomorrow.

The picture really doesn’t do it justice, but these things really feel clean.

I’ve been going at quite some pace recently and I would like to keep the momentum going while I wait for the tanks to be inspected so I have decided to continue with the leading edge assemblies.

First I scuffed the the remaining internals of the leading edge skins and then I dimpled them with some assistance from Karma.

It looks great inside…

and outside…