The following iron modifications were originally posted in the forum by Bruce, who teaches boat building classes at the Folk School in Fairbanks, Alaska. I’ve reposted Bruce’s images here with edited text. All credit for this great idea goes to Bruce! – Matt
Model aircraft irons (designed for applying plastic covering film to radio-controlled airplanes) work very well for welding the DIY Packraft heat sealable fabrics. These irons generate lots of heat and maintain a consistent temperature – two things lacking from most other mini irons I’ve tried. There are several brands of these irons available, such as the Coverite Black Baron pictured below, and they can be bought at your local hobby shop or online for as little as $19.99 USD.
It’s not essential to modify your iron – you can build a packraft with one of these irons straight out of the box – but the shape and size of these irons isn’t optimized for building packrafts. The bottom is too flat, too wide, the sides have too steep a taper, and the tip is too round, so you’ll find your iron easier to use if you make the changes detailed below. You might wince at the idea of making such drastic changes to a brand new tool, but I think you’ll be glad you did. If you somehow mess it up beyond repair, you can always purchase a replacement shoe for about $7.99 USD.
To make these changes, use a metal file and then sand the surfaces smooth with 220 grit sandpaper. Polish with extra fine steel wool and wipe with a rag, then test the iron on a scrap of fabric to make sure all the aluminum dust is gone and it won’t leave grey marks on the fabric. If you have access to a bench grinder with an aluminum wheel, that will speed things up.