12. Making the bellows

      The very thin vinyl I used to make the bellows for the 8x10 I built 40 years ago was very thin, yet  held up very well, so I looked for some more of the same both at MASCO and Bonds Brothers.  Unfortunately, they didn't have it. I considered ordering on Amazon the cheap Chinese stuff they sell for boats upholstery and that people complain about being too thin, but it comes folded in a bag and full of creases.  I ended up buying the thinest material they had at Bonds Brothers,  which is like a heavy 60" wide re-enforced waterproof tent fabric. It is black on both sides. But it turned out very heavy compared to the original, and I wish I had not bought it. 

     It is too thick to do a traditional bellows construction with ribs between two layers of fabric, so I will try to just fold it as is. I did a test cutting a 15" strip from the roll of vinyl, and it worked, sort of. I first drew all the lines and folds with a white grease pencil, and just  started folding. I used a steel roller to press the creases and clips to hold the folds in place while doing the corners. I used two pieces of wood and two vise clamps to press the folds really hard. It could work, but will be difficult for the full x4 bigger bellows.

      Well, I got the vinyl, so why not give it a go! I rolled it out on the dining table and laid out every fold with a china grease pencil. I can clean the lies later with naphta. The folds will be 1 3/16', and so is the overlap for the corners. The sides will be 22".

    

     started folding and pressing the creases with my steel roller, but then it would be hard to do every fold that way, so I started just folding by hand and creasing with my fingernails.  I use large steel office clips to hold the folds together and to press the corners. I will need more of those, so I ordered some even larger ones.  It is getting kinda messy... Hope a dozen will do...