Still Working

A number of people have emailed me to ask if I am still working on the project. Well I am happy to say that I am, though I not managing to keep this blog up to date, which is why people thought I might have quit.

I certainly intend to bring the blog right up to date at some point, probably in the break between finishing the wings and the arrival of the fuse kit. I am also considering moving to a website of my own. However, for now, I will just post a bulletin to summarise where I am at present.

On new years’ day, with the help of my son, Conor, I began to rivet on the top skins of the first wing (the right hand one). We finished up the job on the following day.

Looking back over the year, I see from my diary that I have worked a total of 501 hours and 37 minutes, which is astonishingly close to my target of 500 hours per year. I worked on 125 days (roughly every third day) so the average time worked was therefore 3 hours and 40 minutes. However, as you might expect, this divides down into evenings of 2-3 hours and full days of 6-9 hours.

In total, I have now spent 609 hours,12 minutes on the project, of which 280 hours 35 minutes were on the empennage and 326 hours,37 minutes so far on the wing. These figures do not include breaks, time spent buying supplies or time spent researching the forums or other builders sites to see how they approached each task.

I seem to be slower than other builders but that is no harm, especially if it results in good workmanship and a nice result. I am also enjoying the process immensely and I attribute this partly to still being a non-pilot. I think that flying or training to fly would distract me from the project as well as diverting money from it. Be assured, I do want to fly. In fact it is the stuff of my daydreams. However, for the moment I am very content with building.

There still isn’t a schedule for the rest of the project. All I have is some loose 'expectations’. For instance, I expected to have finished the wings at this stage but they won’t now be finished until sometime in February or March. The fuse is now on order and will arrive during March so that should be finished in the spring of 2010.I plan to begin training at that stage, while working on the finishing kit. All going well, I should spend 2011 and spring of 2012 on engine, wiring and systems and move the plane to an airfield for assembly and painting duriing the summer of 2012 with first flight happening late that summer. Now all I have to do is work out how to afford it all.

Got it! - proving that I have lost it

Thursday 28th August 2008. 4hr 40min.

Found problem with main rib placement and corrected it. Assembled and riveted main wings to right spar. Riveted right aft spar assembly to main ribs.

With a clear mind, the problem with the main ribs soon became obvious. As I suspected, I had indeed allowed some ribs to be exchanged between the left and right wing sets. However, this had happened at the first assembly stage, so they had been marked as belonging to the wrong set and this was what had confused me yesterday evening. The ribs involved are the three ribs that are tightly spaced under the wing-walk doublers, immediately next to the inboard rib. The inboard rib and the three which follow it should all have their flanges pointing inboard, whereas I had these 3 pointing outboard. A look at the high-res version of the photo of the fully assembled wing skeleton (with bottom skin) that I took a while back confirmed that the orientation was wrong.

So this was easy to fix by swapping the affected ribs between right and left wings. Of course, this means that these ribs have been match-drilled to the wrong spars, skins and stringers. However, I see lots of forum entries on the subject of match-drilling replacement fuselage or wings skins and the conclusion seems to be that holes can be simply drilled out to full size without being assembled to the frames and adjoining skins. The kit seems to be so accurate that match-drilling is somewhat superfluous. Because of this, I fully expect that the ribs will match up with everything else without any problems. We will see, but there was no way I was going to leave them facing the wrong way as it would have made the riveting of the bottom skins very difficult.

So, problem solved (sort of) and on to the riveting. This was easier than I thought it would be. I used Smitty's set up and method, taking out one rib ahead of the one being riveted in order to allow easy access to both sides of the spar at the point being riveted. One thing to watch out for here is that the tip rib is riveted in assembly with the tip rib of the leading edge assembly so it can't be done at this stage - I left it clecoed to the spar. However, I think the aft end of this rib can be riveted to the aft spar and doubler.

The solid reinforcing bars on the forward side of the spar make it a little awkward to set the top and bottom rivet on each rib, particularly at the point where the bar is about the same height as the unset rivet. I switched from my biggest mushroom bucking bar to a rectangular-faced bar for these, so that I was not riveting on the edge of the circular-faced mushroom set. I had also protected the reinforcing bars with medical tape. I used the 1/8 double-offset set in the rivet gun and taped it to the gun with duct tape to keep it from rotating and to keep the gun from scratching the primer on the ribs. With the aft end of each rib still unattached, it was easy to move the rib aside to get a straight shot, so I am not convinced that the double offset rivet set was strictly necessary. I did have to use plenty of clecos, however to ensure that the flange of the rib stayed flush against the spar, while bending the rib out of the way.

Riveting on the aft spar was another job for the air squeezer, this time with the longeron yoke. I had to be careful that the aft flange of each rib was clecoed in its correct place as there are a number of places where it is easy to be confused. Careful attention to rivet sizes and types is also essential here. I decided to go up and down the spar finishing off each size of rivet before going on to the next size because otherwise I would have had to change the gap between sets literally dozens of times during the job.

The end result is very pleasing. Most of the holes in the aft spar are occupied now, the only exceptions being the places where flap and aileron hinges and fairings go.

Going mad!

Wednesday 27th August 2008. 1hr.

Fitted main wing ribs to both spars.

Dorothy is away this week, taking her mother on a short holiday so I am trying to make as much progress as possible. However, things did not go my way this evening.

You would think that it would be simple to put marked parts back in their marked positions but the main ribs would not go onto the spars as per the markings and the plans. Just before starting, I had had a phonecall from my sister, who lives nearby, to say she would like to call by, so I knew I did not have long and this may have contributed to the confusion. To try to sort it out, I fitted the ribs to both spars in case ribs had got mixed between them, even though I thought I had kept the sets apart.

In the end, I just left it there and tried to forget it while I had a great chin-wag with Fanchea (my aforementioned sister). She was suitably impressed with the results of our interior re-modelling project and not at all interested in the plane, which suited the moment perfectly.

Wing structure starts to go together

Tuesday 26th August 2008. 2 hr

Riveted both aft spar assemblies. Riveted #6 inspection platenuts on right wing main spar.

The shop where I bought the compressor (Halfords); a chain of motor parts, accessories and tools suppliers) replaced the regulator for me under guarantee. In fact, after a call through to the manufacturer's help desk, they were willing to swap the entire compressor, but I felt (stupidly, perhaps) that that was too much trouble and it would have involved a trip home to get the current unit. I was just happy to be able to get straight back to work.

With the new regulator installed, I quickly put it to work and began the final assembly of some wing parts for the first time. Platenuts aside, this was the first time I had permanently fixed wing parts to each other and it felt good. It was an easy job for the air squeezer. Having taped up the holes to be left open last night, there was no chance of a boo-boo and that made the work quicker.

I was not happy with the AN470AD4-5 rivets called out for the W907-D and E doublers. They looked too long. I often make my own calculation of the right rivet size rather than take Vans word for it and it is surprising how often they call out really long rivets for the thickness of material involved. I can use my cheap digital calipers to measure the total thickness of the materials but, more often, I look up the thickness of each part in section 4 of the manual and add them up before adding 150% of the rivet shank thickness. Another method is to use the little blue gauge supplied by Isham in their kit. The cut out in the corner for each size of rivet has one side set to 150% of rivet diameter and the other side set to 200%. On this occassion, I decided to use AN470AD4-4s instead and the shop heads still more than filled the shop head gauge.

The missing platenuts from the spars arrived by post today from Vans so I was able to install the final #6 platenuts for the inspection plates on the right wing.

Kaboom!!!

Monday 25th August 2008. 2hr

Tidied up after priming. Assembled both aft spars. Dissassembled left leading edge. Marked leading edge ribs for position. Stripped blue vinyl from rivet lines of left leading edge skin.

It was dark by the time I finished last night, so everything was just thrown back into the shop. This evening had to start with a tidying session to make the shop habitable (and workeable) again.

I had just clecoed the parts of the two aft spars together and set up for the first rivets when I noticed that I had no pressure in the hose, even though the compressor had run normally when I switched it on and had cut out after about the right amount of time. On opening the compressor cabinet, I could see that the regulator knob was missing. I found it on the floor of the cabinet with some other parts. The pressure adjustment knob is plastic and fits to a threaded plastic moulding that screws into the top of the regulator. The knob varies the compression in a spring beneath it, which pushes through a plastic flap sitting on top of a valve between the top outlet chamber and a filter chamber below. Everything above this valve had blown off.

Nothing seemed damaged so I tried just screwing it back. No luck. It just blew again more or less immediately. Fortunately, the compressor was bought new and is just entering the last three weeks of its one year guarantee. I took the complete regulator off to return to the supplier tomorrow.

So I had to find some other jobs to make myself useful for the rest of the evening. Getting the blue vinyl off the rivet lines of the skins is always a good fallback to fill in time. As that involved disassembling the left leading edge, I went on to mark the ribs for position, using the same scheme of punch-marks beside holes that I had used for the main ribs.

Primed and ready

Sunday 24th August 2008. 9hr 15m

Etched main wing ribs and aft spars and doublers and primed them all.

What a long day. Fortunately, it was the first genuine summer's day in Dublin since June. The rest of the summer has been a complete wash-out, for the second year in a row. It makes you wonder whether there will be enough flying weather to justify owning a plane.

I switched back and forwards between the etching parts and priming them. The sunshine was very helpful in drying the parts quickly. On the other hand, when refilling the paint hopper on the gun, the paint was extremely slow to pass through the 125micron strainer I was using. This may be an indication that the paint was too thick but I did not want to over-thin it. On the emp, I felt the paint was too thin by the time it got to the recommended viscosity as measured with a Dupont viscosity cup. this time, I decided to just 'wing' it.

Each of the two coats of primer is itself a two step process, as parts need to be turned to get at the other side. With the spray booth, I can hang quite a lot of parts and avoid having to turn them. Fortunately, the primer dries in about 10-15 minutes (noticeably longer at lower temperatures, as I noticed when evening drew on and the light faded)

As the day wore on, the last parts got etched so I was sitting around waiting for parts to dry so that I could shoot more primer. By that time, I was glad of a chance to just sit in the shop and read ahead through the manual.

Ready to Prime

Saturday 23rd August 2008. 5hr 30min

Completed tank attach platenuts on left spar. Set up for priming. Marked remaining parts "right"/"left". Cleaned ribs for left wing and aft spar parts. Etched and 1st coat primed all aft spar doublers.


My Mum & Dad came for a visit last night so I got a night off. Coming back with a fresh mind to those three platenuts on the aft face of the spar near the root, I eventually got them done without much additional drama. I was probably just tired on Wednesday by the time I got to that job.


So, back to priming. This is not a job I enjoy. I envy builders who just take out a rattle can and shoot, like it was something that barely needed mentioning. This Stewarts primer/sealer system requires two steps (cleaning and etching) before shooting anything. The shooting itself, like all spray painting, involves significant set-up and climbing into a sweaty overall and mask for the job itself. The last time I did it was in winter, so I set up a spray booth, which took up half the workshop and left the remainder very cramped. This time, I am hoping for good weather and I intend to do the spraying outside.

From my experience with the emp, I learned that the cleaner will take off sharpie markings so it is important to mark each part in a way that will still be seen after the primer goes on. As each part on the aft spar is unique, it is only necessary to distinguish between those for the left wing and those for the right. I decided to use a pattern of dots made with the centre punch for this. I chose to use ":.." for left and "..:" for right. This can still be confused depending on which way up you read them so I adopted the convention of always putting them on the aft face of the part , near the bottom.

I had not forgotten how tedious the job of preparing the parts is and it fully lived up to expectations. Cleaning the parts thoroughly with the Stewarts cleaning compound (diluted as per the instructions) and a piece of red Scotchbrite pad is a lot like washing the pots after dinner, which I am also not fond of. Never having been caught short of cash in a restaurant, I have never had to spend most of a day at the sink, but this was a good simulation.


After the scrubbing step, I rinsed off each part and left it to drain (dry if possible). Next it has to be painted with Ekoetch (diluted with an equal volume of water). This has to be left on for about three minutes before thoroughly rinsing the part and letting it dry. At that stage it is finally ready for the primer. Getting a process going to move all the parts through these steps certainly keeps you on your toes.