TFB - Tough Foam Board (NOTE: The 'T' definitely doesn't stand for Tyvek)Materials Needed

• Dollar Tree Foam Board
• Roll of Tyvek (Hardware store)
• 3M Super 77 (Hardware store)

I'm a big fan of all the Flite Test planes and I think the new water resistant foam board is great, except that I love putting LEDs in my planes.  Not only do the LED's help when flying in the early evening (which starts really early in the North Eastern US during the winter), but they can really look amazing.  

However, since FT no longer sells white foam board and the DTFB is almost useless for plane building I was quickly running out of options.  After thinking about possible solutions I realized that Tyvek would make an amazing covering for the foam.  It's white (mostly, more on this later), it's weight and opacity is similar to paper and it's _much_ stronger (at least in tension).

Step 1: 

Remove the paper from the existing foam board.  If you have tried this with the almost useless DTFB you may have had mixed results (I once spent an hour and only managed to peal  about 1 sq foot).  So get a wide pan of water boiling and slowly move the sheet of foam board over it, do one side at a time. When the board reaches maximum curl (still fairly gentle, but it will stop curling any more only takes 1-2mins), start pulling the paper off, it should peel off in one easy pull, if it starts resisting stop and steam it a bit more.

Step 2:

Once you have a clean piece of foam it's time to put the Tyvek on.  This is much easier if you cut an appropriate size piece from the roll (rather than trying to put the foam down on the roll).  To measure I like to put the pice of foam (before spraying) down on the roll and then cut an inch or two past the edge of the foam.  Cut two pieces (one for each side of the foam).

Step 3:

Lay out the foam and the Tyvek (printed side up), and spray the foam with Super 77 (you want the printed side of the Tyvek up so the inevitable overspray is on that side).  

Step 4:

Attach the Tyvek to the foam. This step is much easier with two people. 

Pick up the Tyvek and have one person hold one end while the other person aligns the Tyvek with the edge of the foam.  A bit counter intuitively, just overlap the Tyvek a small amount (1/8" to 1/4", ~1cm), it's easier to ensure it's not skewed that way.

One of the great things about Super 77, is that you have a few minutes of working time.  So if you put it down crooked (and you will), you can pull it back up and try again.  Once you have the first edge of Tyvek nicely lined up with the edge of the foam, slowly work your way across the foam pressing the Tyvek down firmly.  It's really important you don't end up with any wrinkles.  If you get wrinkes or your Tyvek is skewed and  misses the far corner, you can pull it back up and try again.

Press down firmly, do a few inches at a time.
 

Step 5:

Go back to Step 3 and repeat with the other side of the board.

You can see the overlap on the bottom edge
Completed piece of TFB

Notes:

• The TFB looks and feels really good.
• Tyvek is really tough and a plane built this way should be fairly durable
• TFB should not warp/delaminate due to moisture.  It should be entirely water proof.
• It is possible to get entirely white Tyvek.  It also comes in different weights (roughly lighter, the same and heavier than the kraft paper)
  There are varients of the white Tyvek that can be inkjet printed  (intended for wide format printers for banners) and it has excellent whiteness.
• Tyvek comes as a roll of material, so you can join pieces of foam (just like normal), then take the paper off and cover with Tyvek as normal.
  This works great for the Arrow.
• One downside is that it's not as stiff as either the white or brown foamboard.  It's also not as apt to crease when it gives though. 
• Tyvek melts at about the temperature that the foam melts which is a bit below the tempurature of the tip of my hot glue gun so if I touch it with the tip it will warp a bit. Importantly though I haven't had trouble with the actual glue.