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.

New Tools!!!

Tuesday 29th July 2008 1hr 30min

Cut tie-down brackets and tapped for rings. Began edge-prep of main and leading edge nose ribs.

I went out yesterday evening to buy the lumber I need for the wing stand and the flat table for the flaps and ailerons. I was very happy with the 4X2 lengths I got. They are 8ft so there will be no wastage. More importantly they are dead straight and heavily grained so they should resist warping. I will glue and screw two lenghts back-to-back to make the posts for the wing stand. I could only get half-inch MDF so I got two sheets and had them ripped in the store. I will glue two layers together on each side of the frame.

Always nice when you get a box of new tools in the post. Included was a low-value torque wrench, a heavier mushroom-head bucking bar that lots of people find very good on the wing skins and a tap for the tie-down brackets, as well as the rings themselves. I had decided to stick with the drop-forged items with their American thread patterns because using localy sourced eye-bolts would have meant drilling out the holes to a metric size and tapping accordingly. This would have been the only metric fitting on the plane and might be confusing to anybody other than myself. Some Torque Seal to identify torqued-up bolts, Permagrit countersinks in #30 and #40 for fibreglass work and a 21/64 drill bit as recommended by Smitty for the Delrin aileron stops made up the rest of the consignment. I am going to need a quarter-inch to three-eights drive adapter and a set of 'crows feet' for the torque wrench - I don't know what possessed me to order the quarter inch drive because my socket set is virtually all three-eight.

Boy, my band saw made a fuss about cutting these tie-down sections. I use a 16tpi blade and it seemed to be melting its way through the metal rather than cutting. Luckily, I had left plenty of margin and I got things nicely cleaned up with the sanding belt and the polishing wheel. Actually tapping the holes was a non-event. I used Beo-Lube (another item in today's goody-bag) and repeatedly went two turns forward and half a turn back, ocassionally coming all the way out to blow off the shavings and re-lubricate. the tap is only just long enough though I went as far as it would let me. I may have to shorten the threaded portion of the rings so that the flange of the rings seat up against the wing skins, although having a slight gap under the flanges might be a blessing for the paintwork. I will decide when the plane is finished and painted.

I made a start on the edge - preparation of the main ribs. This is going to take forever!