Thursday, February 28, 2008

Front Seatback Bulkhead Finished

Well, pretty much finished anyway. I cut and floxed the corners Wednesday night and went to the mall with Julia to try and find some maternity clothes. After we got back I glassed the back side. I worked inside as it was a bit too cold to work in the garage and I was impatient to finish the seatback.

Detail of floxed corner:

And the finished piece (now in the garage after cure and knife trim):

The pretty much finished part is a couple of air bubbles I found where the foam had been 5-minute epoxied to the workbench (you can see them in the foreground of the pic). I don't think that I let the micro cure in the holes long enough before I glassed out the back. Should be a pretty simple repair.

Next will be bulkheads F-22 and F-28. Before I can start on those I have a lot of drawing tracing to be done. I found that setting up my first seatback bulkhead (yeah, guess I forgot to mention that - it didn't go well, but after doing some more online research I've found where I went wrong. Aircraft Spruce, in their wisdom, supplies you with two pieces of the 3/4" foam used in this step. In my research I saw that others had benefited from that as well so I didn't feel too bad.) set up on a card table with a bright light works very well for my drawing tracings.

Tuesday, February 26, 2008

Beginning Chapter 4

It's finally warm enough in Texas for me start working on Chapter 4! Chapter 4 consists of the seven fuselage bulkheads to be used in the aircraft. The first is the front seatback. The seatback is 28.8" X 48".
The instructions say that you might have to glue two pieces of foam together because of the size, but Aircraft Spruce supplies pieces of foam large enough that you don't have to do any gluing. After cutting the foam to the right dimensions, I cut a 45° angle along the top of the bulkhead as it will be installed at a 45° in the fuselage.
I also went ahead and trimmed the the top cutouts although the plans say to do this step after glassing the first side. After reading problems that other builders encountered when trying to cut these after glassing I went ahead and precut these. I decided to wait until actually fitting the bulkhead in the fuselage before making the other cuts though as many suggested that this might make life easier in chapter six. We'll see how I feel when trying to cut the bulkhead then.

Detail of front seatback top front cuts:

After cutting the piece I cut the bid. fiberglass to be used in glassing the front side. The bid. has to be cut and put on at a 45° angle. The problem is that the fiberglass roll isn't wide enough to cover the piece with one section so you have to use a small triangle to finish each of the two plies used. I must admit that I'm not 100% comfortable with butting up the edges of the fiberglass, but that is the method prescribed in the plans for use with bid. fiberglass. Uni fiberglass has an overlap of 1" when putting two pieces together, and I must admit that I was tempted to overlap the bid. but followed the plans and simply butted the two pieces together.

Here's a pic of the fiberglass cut out over the piece before starting glassing:

I then applied micro to the front of the front seatback bulkhead after 5 min epoxying the bulkhead to the workbench:
Then I glassed in the two plies at opposing 45° angles and peel-plied the edges and the area where the two pieces of the second ply butted together:

I hope to finish out the seatback bulkhead tonight (or tomorrow a.m.) if it stays warm enough.

Oh, and just because I like my speedometer-like thermometer:

Hope to post again tomorrow a.m.