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
http://www.plasticsnews.com/subscriber/opinion2.phtml?cat=5&id=1203711884
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
This page updated April 18, 2008
Chap. 3: Road Testing the Long Tail Mar 2, 08
Chap. 1: Streamlining Saves Fuel
Chap.2: CAD Streamlined Body
Chap. 4: Planking with Foam
Chap. 5: More Wind Testing Apl. 7, 08
Chap. 6: The Final Shape Apl. 17, 08
Chap. 7: Decisions about Details May 10, 08
Page 8: Making the Center Bulkhead June 1, 08
Chap. 9: Rear Bulkhead and Truck bed June 8, 08
Chap. 10: Finish Rear and go for ride June 17, 08

If you have not yet watched my DVD, How they Got 470 mpg it is time to get it for the basic foundation for what we are doing here

Chap. 11: Finish the Tail June 29, 08
Chap. 12: Heading for Ohio, July 13-23, 08
Introduction to Fuel Economy
Chap. 13: Riding in the Midwest July 24, 08
Chap. 14: Vintage Days Ohio, July 25-7, 08
Chap. 15: Summary to date Aug 12, 08
Chap. 16: Adding Weight to the Front Sep. 1, 08
Chap. 17: Truth and Motorcycle Design Sep 4, 08
Chap. 18:

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