The Search for Fuel Economy

Pages from a Designers' Notebook Readers comments

Chap. 4: Planking with Foam

It is time to begin gluing in the foam. I use cheap, often free, contractor's urethane building insulation that has been damaged. Corners knocked off, etc. Free is good. The downside is that I must peel the foil off before I glue it because the foil messes up the seam later when I will file away the foam.

Cut panels a little oversize and glue them on. Liquid nails is good. Buy a lot as a tube seems to get consumed for each piece of foam.

I just cut a rough shape with a knife. If one side needs to be square, I run it through my bandsaw. I try to leave no gap. At least an overnight is necessary before I can work on shaping.
Add planks to the bottom. I am not sure what this thing is going to look like, so I leave the blocks way oversize. All I know for sure is that the shape is controlled by the two bulkheads and the perimeter. I trust that I will be able to connect it all up with a smooth, srtreamlined shape. For sure, I will be able to fit into it comfortably.
I use a common wood saw to whack away the big chunks and then a big coarse file made for automobile work - from Eastwoods to get it closer to the shape it needs to be.
I know from previous experience to leave everything a little oversize. Things seem to change as I add the rest of the foam blocks.
Urethane foam is very dusty and makes a mess in my shop. I wear a mask and am always vacuuming the stuff up. I think about which bugs will want to eat the dust when it gets to the landfill. I suspect that there are no such bugs, which is troubling. You may be interested in reading a story about plastics I wrote for Plastics News called: Plastic Fairings, Plastic Bottles and Plastic Beetles
I just file away everything that is not part of the streamlining. I don't do this all at once. I file a little. I stand back and stare at it a little.

It "tells me" what it wants to be. All the designs of my life have been done this way.

After a while, its streamlined fishy shape begins to emerge.

I find this to be pretty satisfying work. Checking my E mails, it is clear that at least a few interested folks are following along with me. The price of used Helix scooters may be going up, too..

Streamlining: Round at the front... pointed at the rear. Always been this way... always will be this way. It is God's finest shape to slip through the air and water..
I am beginning to daydream about this new streamlined body on my Helix for a real, cross country ride this summer, maybe from California to my brother's in Illinois. There is much more to do. This is only one side and I must make the other side. Then I must figure out how I will make my fairing with this shape. The fact is, I am not sure just how I will proceed. One step at a time.
Next step: Finish planking it with foam and start on the other side

Master Index to the Last Vetter Fairing Story

This page updated April 18, 2008