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Cozy Mark IV

Cozy Mark IV : Time and Expenses

Chapter 7: Fuselage Exterior

In this chapter you will finish the outside of the fuselage.


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Chapter 7

1. NACA scoop 12/1/04   3 Created template for NACA scoop, outlined on fuselage bottom, cut out foam, trimmed to shape, and micro'd foam to fuselage bottom.  Cut out the wooden braces for the LG bulkheads and floxed in place.  Cut out the foam to go on the outside of these braces, but did not micro in place, as the braces' flox was still drying.
2. NACA scoop 12/2/04   4 Micro'd the foam to the braces.  Cut out the braces that go between the FW and aft LG bulkhead.  Floxed in place, added 2 plies BID, and micro'd 2" foam over them.  Now, in order to finish the scoop you're supposed to use 3/8" PVC foam in the space between the FW and aft LG bulkhead, but I am out of this kind of foam.  First I didn't have enough foam for the spacers, then I didn't have enough BID for the taping, and now I don't have enough foam for the scoop.  In all fairness, I believe that this last shortage is my fault, for not saving the scraps from the fuselage bottom.  But to be short for three separate things in the space of a couple of days, well, grrr.  I've got two separate orders in at Wicks to send me more stuff, and now I'm just fiddling around until it arrives.

I also prepared the 22" sanding block today, in preparation for sanding down the NACA scoop.

There are a bewildering number of details that the plans are silent about, or that you have to be Sherlock Holmes to figure out.  For example, the horizontal braces between the FW and aft LG bulkhead.  The dimensions in the plans suggest that one side is essentially square, and the other is angled to fit up against the side braces (where the bevel is).  But, the square side cannot actually be square, it has to be angled to fit the line of the NACA scoop.  If you cut the things to the dimensions in the plans, they won't be long enough.  So the plans say to trial cut from foam first, but they don't explain why.  Elementary, my dear Watson.  Okay, then, you put the 2" foam on top of them, but the plans don't say anything about shaping this foam down to the contour of the bulkheads.  You have to notice in the pictures at the end of the chapter, where there's a reference to this.  So many of the little mistakes I make that I have to go back and correct could have been prevented by a little more clarity in the plans.  I'm being as careful as I can be, but often I don't realize I've made a mistake until I'm past it.  Sometimes it seems to me like the plans are written for someone who already knows how to build one of these things, and the plans are there just to remind you of the major steps, without worrying about all the little details.

3. NACA Scoop 12/11/04   .5 Cut out and installed 3/8" PVC for the rear part of the scoop.
4. NACA Scoop 12/21/04   4 Sanded down 1/2 of the scoop, cut out the ridge for the LG cover.
5. NACA Scoop 12/22/04 91 6 Sanded down the other 1/2 of the scoop, cut out the aluminum inserts and floxed them in place.  The cost was for a band saw, which turns out to be an essential piece of equipment; and a surform plane.
6. Sides 12/23/04   4 Shaped the tapers on the sides by the FW.  Started the 45-deg cut along the bottom of the fuselage sides.  I made a 12" long blade for my jig saw from a band saw blade to make the cut.
7. Sides 12/24/04   6 Finished the 45-deg cuts, did the hand cuts, and sanded and shaped the fuselage sides, on the bottom.
8. Brake & F22 12/26/04   4 Today I sanded the 1/16" depression around the landing brake and F22.  The popsicle sticks used for stirring epoxy are perfect for this.  Also marked and cut out the step reinforcement.
9. Step reinforcement 12/27/04   .5 Cut the step reinforcement to fit, and micro'd it into place.
10. Step reinforcement 12/28/04   .5 Sanded down the step reinforcement to align with the fuselage exterior.  Ordered the antenna kit from RST, so it may be a couple of weeks before I can glass the bottom.
11. Landing brake 12/29/04   1 Put the 1" border of duct tape around the landing brake.
12. NACA Scoop 12/30/04   .5 Cut out the BID and peel ply for the 2 plies inside the scoop.  Will probably glass this tomorrow.
13. NACA scoop 12/31/04   3 Glassed the scoop, 2 plies BID, peel ply.
14. Marker antenna 1/27/05   2 Decided to go with the marker beacon antenna on the bottom, as suggested by RST.  Cut a trench for the coax and a hole to enter the cabin fore of the IP, cut the foil tape and installed it in place, and soldered the coax to the tape with the toroids in place.  That should be the last thing to do before beginning to glass the bottom.  Now all I need is a nice, warm day...
15. Glassing bottom 1/29/05   7 Made a flox corner at the scoop, micro'd the entire bottom, and then laid the glass (with my wonderful wife's help!).  2 plies UNI at 30-deg, plus 1" overhang at F22 and the bulkheads/FW.  Added the reinforcing UNI layups on the gear attach and engine mount points.  Added peel ply.  Boy, it doesn't sound like a whole lot, but it took all day!
16. Shaping the sides 2/1/05   4 Cut the templates for shaping the sides, began the shaping.
17. Shaping the sides 2/2/05   3 Completing the shaping of the sides.
18. Glassing side 2/3/05   8 Glassed the pilot's side of the fuselage.  3 plies UNI, 3 reinforcing layups on the top, 3 plies reinforcing UNI at the engine mounts, 2 plies BID at the same place, and then peel ply.  I also trimmed the glass that overlapped the bottom, and peel-ply'd the seem.  Dude, this was a LONG day.  I'm running low on all supplies (UNI, hardener, resin, peel ply), so I might have to wait until I order the next chapter's supplies before finishing the other side.
19. Cutting glass 2/4/05   1 Cut the glass for the other side; we had enough!.  Poured one cup of epoxy to start the glassing, and then convinced myself that I don't have enough epoxy, so I've decided to wait until the next order comes in.
20. Glass side 2/12/05   5 Order came in yesterday.  Glassed passenger side.  This went much faster than the pilot side!  Got a drop of epoxy in my left eye, yikes!  I ran to the nearest bathroom and washed out my eye, and then ran upstairs where Amy rinsed my eye with saline, and then with more water.  We then waited a few minutes to see how my eye was doing.  I thought it was swollen, but it didn't look like it to her.  After about 10 minutes there was no sign of any lasting harm, and no loss of visual acuity, so I went back to work.  Now at the end of the day I'm glad to report that there are no lasting effects.  It was just the tiniest of specks that went in my eye, but I could feel it and instantly knew I was buggered.  I went to Lowe's afterwards and bought myself some splash-guard goggles.
21. Trimming     1 Trimmed the glass cloth, sanded the edges, and took the fuselage down from the A-frames and let it rest on rubber mats on the floor.  We took the requisite right-of-passage photos with us sitting in the plane.  :)

Chapter total: Time 68, Cost $91.00

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Last modified: Sunday, February 13, 2005