Dimpled Right Tank Skin

June 4, 2011

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Well, Andrew went shopping today!

It’s been brutal in the shop, so I put up the electric heater I had on the bench and put in its place this new VORNADO. For such a small package, it does a pretty good job of moving air. You have to have it pointed right at yourself though.

The VORNADO. (insert ominous music here)

Also, I bought the craftsman circle cutter for the large 6″ holes I need in the fuel tank inboard ribs.

Time to cheat death.

i also picked up some 1/4″ and 3/8″ drive drill adapters. I hate having to use a ratchet all the time for bolts. Now I can use the drill.

Oh, and a 7/16″ drill bit for the inboard rib vent fitting holes. The -4 sized AN hardware requires a 7/16″ hole.

This stupid drill bit was $14. Jeesh.

Also, I bought a nice little kitchen scale. I thought about saving some bucks and going with the analog one, but I didn’t know if I would be happy not having the digital readout.

This one was about $30.

These pliers weigh 155 grams.

Okay, back to work, Andrew!

I broke out the c-frame again and loaded in my tank dimple dies. On all of the other skins, I’d been putting the male die on the bottom, putting the hole in the skin over the die, lowering the female die, and then holding it in place while I struck it with the hammer.

On these skins, I’m flipping the skin over (so the other half of the skin hangs off the front of the workbench toward the ground).

This means I have to have the female die on the bottom, and the male die on top. To avoid my figure-8 dimple from the leading edge, I removed the return spring from the c-frame so any fidgety hands won’t cause anything to move.

Here I am about halfway through with the bottom half of the right tank skin.

(Whiny voice:) My hand got really tired (the hammer is sooo heavy, sissy boy!), so I took a break.

Not sure why I weighed a cleco, but I was curious.

13 g. Hmm.

Back to work again. Here’s the bottom half of the right tank skin.

Since there are more holes on the bottom than on the top, I am more than halfway done!

A closeup of the top skin dimpled.

The hole (get it?) thing dimpled.

At this point, I had been working for 1 hour and 20 minutes, so I felt like I should find something to do for 10 minutes just so I can log 1.5 in the build log. I broke out the #8 dimple dies and dimpled the #19 holes in the outboard edge of the tank skin.

You can see the size difference between the #40 and #8 dimples (The numbered comparison is not right here. #8 screws require #19 holes, so you are comparing #40 to #19).

With a few minutes left, and a new tool just itching to be used, I broke out the 7/16″ drill bit and drilled the vent fitting hole in the inboard rib.

I’ve been following a few threads on VAF recently, and some people are really freaking about about an exact location for this. I followed Van’s directions explicitly, which say “approximate location.”

Ha. I didn’t even give myself a starting mark!

Looks good.

Then, I pulled out the -4 fittings and screwed them in, just to see what they would look like.

The plans show this pointed foward. Okay.

The VORNADO!!!!!!!!!!!!!

1.5 hours. Proseal arrives on Monday. Next week is the black death!

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Right Tank Stiffeners, Z-Brackets, and Countersinking

May 27, 2011

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First thing, I have to give some mad props to Van’s.

If you remember from yesterday, I put in a web order with Van’s for some stuff. At the top of my list was that leading edge rib I messed up a few posts ago, and I FORGOT TO ORDER THE RIB!!!

Anyway, here’s how a short interaction with Van’s (e-mail):

Me: Good morning, Barb…[snip]…Is there any way you can add an item to my order? I need one of the following, copied from “the list”: W-408-1R, NOTCHED NOSE RIB 032, $23.80. If not, I understand…it was my error. But if so, thank you so much!

Within an hour (and definitely before normal business hours in OR):

Barb: Andrew, I have forwarded this on to our parts department who will download
the web orders this morning and get it added to your order.  Barb

Then, after about another hour:

Dear Andrew,

The part was added to your order as you requested.  I just caught it
prior to being shipped this morning.

Van’s order dept.

Oh man, Van’s is awesome. Also, I figured out from the charge that shipping (UPS ground) and handling from Van’s was about $15. Not bad.

Anyway, being a Friday, I was looking for something relatively painless to do tonight. I pulled out the T-711 bundle and started in on the stiffeners.

Here's the bundle.

I ended up getting all of the stiffeners ready, for both tanks. I’ll put the ones for the left tank away until I’m ready to do that tank.

Below you can see 3 of the four sizes of stiffeners. The fourth size is pretty small, and I left them out of the picture.

Three sets of long, one set of kinda long, one set of kinda short.

Lastly, I took off all of the vinyl. If I were smarter, I would have pulled the vinyl off before cutting them. It would have been a lot easier.


It was a little late to fire up the scotchbrite wheel, so I pulled out the right z-brackets and clecoed them to the spar. I spent a good five minutes staring at the plans to make sure I had them in the right orientation.

I'm doing this because I never matchdrilled the rear flanges of the interior ribs. The z-brackets and baffle are full-size holes, so I just need to run the drill through them with the flanges in place.

Drilling some holes.

Moved the clecos, drilled the other three.

Then, since I wasn’t too tired yet, I broke out the microstop countersink and started countersinking the skin-to-baffle holes. You do this so the baffle is easy to slide in place with the all pro-seal flying around. If it were dimpled, it would be harder.

Countersinking a skin this thin definitely leaves a knife-edge, but that’s what Van’s calls for here.

I’m planning on using the thicker tank dimple dies everywhere else, which should leave a little extra room for proseal underneath the rivet head, but I couldn’t bring myself to deepen these countersinks at all. We’ll see if it works out.

Looks good to me.

Much countersinking ensued...

A closeup, for those of you who are interested.

Anyway, it as a nice night in the garage. 1 hour, and getting closer to the black death.

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