A Cunningham is a simple arrangement of pulleys and a hook attached to an eyelet (cringle) directly above the foot of the mains’l.
This Experiment I will rate as a partial success. I discovered, after the fact, that my little sewing machine wasn’t quite up to the job. I had sewn a series of triangle reinforcements onto the mains’l to strengthen the sail where the cringle would go before I realized that the opposite side of my zig-zag stitching was not drawing down correctly. Basically the point where the top and bottom threads twist should be inside the layers of fabric and mine are on the bottom side of the fabric. There are so many passes of stitching that I’m going to go ahead and give it a try.
I am beginning the search for a better grade machine, one with the strength to pull the proper tension through 5 layers of sail fabric.
The idea is to create a series of 3 semi-triangular, nested reinforcements of Dacron sail cloth.
I started with a 5x5 inch modified triangle and then increased each of the next two by 1 ½ inches in each direction.
The Third modified triangle I increased by an additional ½ inch on all sides. This gave me extra fabric to create a hem to give a more finished look to the reinforcements. I used double sided seam tape to hold the hems and the reinforcements together and to the mains’l. All modified triangles had their 90 degree corner stacked directly on each other.
I placed the group of reinforcement as close to the leach rope as I could get it and still be able to sew it in place.
I next sewed all the way around the group of reinforcements about 3/8 inch in from the edge. Next I sewed many rows of zig-zag stitches inside working toward the center. I left an open zone inside to set the brass eyelet. Finally I sewed a zig-zag all the way around the outside with half the stitch on the group and the other half on the mains’l.
First I created a pattern in my computer but you can easily build one by hand. You will notice that at this point I had not thought about putting a hem on the largest reinforcement which I show in the illustrations above. The tool to the left is mini foot iron fitted with a cutting knife. It get very hot when turned on and it seals as it cuts nylon or Dacron fabric.
I then placed the Dacron fabric over the pattern and traced the pattern with a blue chalk pencil. I added the missing hems at this point.
Using the Clover Hot Knife I cut out the reinforcements. Place a piece of plywood behind the Dacron so you don't damage your work surface.
Pre-fold the hems then open them up and place double sided seam tape on the reinforcement to hold the hem until you are ready to sew.
This is a tool I picked up at Joanne Fabrics & Crafts. I can't remember what it was intended for but it saves my fingers from falling off when you press down the tape and hems.
Failure to press the tape down well will cause the tape to pull up with the backing.
I found that an additional pass with the pressing tool helps to hold the hem until you are ready to sew.
Next tape and stack the other two reinforcements on top of the largest. The Medium size first and the smallest last.
Stack all three with their 90 degree corners aligned.
Position the stack a short distance from the tack gromet and stitch into place.
Punching the Eyelet Hole & Setting the Brass Eyelet
These are the tools you'll need to set a gromet. They are available from SailRite as a kit. Work on top of a board or two so you do not damage the floor below.
I used a Gromet with a 1/2 inch opening. Position the Hole Punch away from the stitching but as close into the
90 degree corner as possible. I didn't want the teeth on the Gromet Rings to cut the stitches.
Place the lower half of the Gromet on the Gromet Die. Place the sail over the lower Groment. Put the top half of the Gromet over the sail (Portion of Groment with Teeth). Place the Punch Tool over the top half of the Gromet and give it a few whack with a hammer. Don't over pound at this point because you don't want to cut through the Dacron.
In this photo you can see the Gromet Die.
This photo shows the nearly finished Gromet.
Sewing Around the Eyelet
The last thing I did was to stitch around the gromet using a hand stitching tool. When stiching around a gromet there is a special brass ring that is usually crimped over the stitching. I don't have access to this so I'm going to see if I can fabricate something to act as a stitch shield. But for starters I may just tape the Cunningham Hook to ease the wear on the stitching.