I’m laying out the pattern for a Coro-gami pannier set trying to make it big enough to take Gigi out camping with me, and I realize that to make this work for both groceries and camping stuff I’m going to need… more stuff!
Specifically I need 2 4’X8′ sheets of 10mm Coroplast to make this work. Color is not a big thing, red or yellow either one will work fine, white will not look as good but will also work fine (Gigi voted for red BTW to go with her orange-red frame paint). When I was doodling this originally I figured I could do the thing with one sheet of 10mm and still somehow manage to get 2 layers of cross grain laminations, but after doing the layout for just the outer layer and having to juggle the numbers several times to get it to fit on a 4’x8′ sheet (it can be done but I had to severely squish my 1970s vintage Dutch Army sleeping bag to make sure it would go) and only having a small bit left over to make a fender from or something. The inner layer would have to be done on a separate sheet of Coroplast.
Now as to why I’m using not just Coroplast but 2 layers of 10 mm Coroplast? Well it’s complicated. This is a project to let me expand my grocery shopping radius, but in order to do that I needed some way of getting ice cream home before it melted, or milk before it went bad. In other words I needed an insulated cooler on my bike. I also found a web site (since taken down) that describe how a man in either England or Australia made an ice chest from 2 layers of Coroplast laminated cross grain with a piece of aluminum foil between to act as a radiant barrier, and it worked as well as the store bought version for less than half the price. Then I saw where someone had built a house from Coroplast that was self-supporting just from the 4 walls and floor made from 12mm Coroplast, and I put 2 and 2 together and got pi so I went back and worked on it until I got 4 😉 The guy that made the cooler used 3M 77 contact adhesive on the foil and the coro to get a sturdy lamination.
Edit: I just checked the Coroplast web site and they don’t make the red or yellow 10 mm any more, just white black and bright blue. Gigi says no blue.