I disassembled all the parts and laid them out for final prep work. I had
no idea how long this step would take... drilling, etc., is fast and easy.
There are hundreds of holes, edges, etc. that have to be prepared, deburred, dimpled.
You just have to turn on the tunes, crank up the fan, and get going on it.
Having a helper makes it go faster, too. Abby came out and gave me a hand...
it was nice to have the company, too!
I was having trouble deburring the inside flange holes... as you can see, my deburring
tool is a speed-deburrer that swivels around. The bent part of the shaft,
however, would go "smack smack smack" on the opposite flange. Then, I remembered
that I'd bought this 12" extension for it! Ah, much better. The extension
has a nice black plastic teflon sleeve that rested on the opposite flange.
Held in place with one finger, you could debur the opposite hold without the tool
hitting anything while you spin it around. (Man, that's hard to explain in
writing... if that didn't make any sense, forget it and move on!). :-)
When it comes to priming, I've decided to prime the inner skeleton parts in their
entirety, except for the skins... those I'll prime just where the skeleton meets
the skin. In preparation for that, you "scuff" up the parts a bit, using a
scotchbrite pad, which removes (or at least dulls) the shiny pure-aluminum alclad
coating. This pictures shows the difference... the part on the left has been
prepared, the others have not. Pure aluminum is highly corrosion resistant,
so alclad, not scratched, will last a long time without rusting. That's why
I'm not worrying about the inside of the skins, except where metal touches metal.
I've seen the inside of several 30 and 40-year-old planes during annual, and they
were perfectly fine without a coating of primer. I figure, I don't need to
carry around the extra weight of excessive primer, and if I later move to the coast
or a high salt-water environment, I'll have a CorrosionX micro-fog treatment every
year or two.
OK, everyone of those holes in the skin needs to be deburred, BOTH SIDES, then I
have to dimple them all to receive flush rivets. Let's get crackin'....
Final cleaning of the parts for priming will involve wiping them down with MEK until
no more aluminum dust comes off them... but the MEK will also remove all my markings.
How will I remember which of these mirror-image parts goes on the left vs. right
side, or up vs. down? I had a sudden idea!
I had a box of old business cards from a previous venture, and used those to create
little 'tags' that I attached with some thin solder strands. Safety wire would
have been the metal of choice, but I didn't have that on hand (yet), so this solder
stepped in to play the part (quite nicely). I wrote down the part's name,
which "end" I was attaching the tag to, and wired it through one of the holes on
the part.
Just tagging everything took a while! It was fun to get to break out the pneumatic
squeezer again and dimple all those holes. Take a careful look at the plans...
only some of the holes on each part are for flush rivets (426 rivets); the 470 rivets
are universal (rounded) head, and don't require dimpling! Also, I kept stopping
before pulling the trigger to make sure that I was putting the dimple on the metal
the correct direction.
We had a surprise (to them) 25th anniversary party for some dear friends; I worked
on this right up to 6pm and the party was at 6:30. The rest will have to wait
for tomorrow... I'm starting to think I might not get this assembled this weekend...