Seatback Brace and Heat Duct Construction, Part 1

While many builders report having breezed through Chapter 6 altogether, It wound up taking us nearly 6 months.  There are a lot of pieces to make! Construction of the seatback brace and heat duct assembly felt quite involved to me, with many small steps, each requiring the curing of the epoxy used in the previous step.  As such, this is going to be broken up into multiple posts.

When you first start construction of the seatback brace and the heat duct, all the pieces are made out of a single sheet of 1/4″ clark foam, or last-a-foam, or whatever they call it nowadays. Here’s what the layout looks like, drawn on the sheet of foam:

Pieces drawn out.

I then fiberglassed the whole sheet, and cut the pieces out on the bandsaw:

Pieces cut out.

As you can see in the above picture, there are also two wooden pieces that get cut out, to hold the fuel valve bracket.  You chisel the foam out of the large triangular pieces to mount these plywood pieces:

Somehow in this process of fitting the plywood to the large triangular pieces, I managed to make two identical pieces, instead of mirrors of each other as called for in the plans.  I completely thought I had it right the first time, and didn’t notice until they were floxed in place.  This was the first mistake that I noticed in chapter 6.

You see, the side of these that is glassed is supposed to be the inside of the seatback brace.  To correct the problem, I glassed the foam side of one of the triangles, and planned on putting an extra ply of BID on the outside, to help hold the fuel valve bracket.

So to assemble this thing, you draw out on the glassed side of one of the triangles where all the spacers and pieces for the map pocket fit  (I thought about just leaving out the map pocket, as iPads have made paper maps obsolete, but thought better of it, as I’m sure we’ll use it for something).  If I were to assemble one of these again, I would find a better way than the plans method, which has you flox the spacers to one side, immediately flox them to the other, and hold them all in place with nails through pre-drilled holes.  As such, it was very hard to get our spacers perfectly square.

Seatback Brace Curing

Bernard Siu seems to have a much better approach, though it may take a bit longer.

Putting the heat duct together was a bit less of a headache, see it clamped together below:

Heat duct curing


This entry was posted in Chapter 6, Errors - Things to Avoid. Bookmark the permalink.

One Response to Seatback Brace and Heat Duct Construction, Part 1

  1. Dad says:

    Yay! New Posties!

    Looks complex.

    — Dad

Leave a Reply

Your email address will not be published. Required fields are marked *