Spar and Batten Tube
For the spar tubes cut one red and one blue at 2" wide x 40" long.
- You then double fold both ends and sew the folds. Make the finished length exactly 39"!
- Then put a piece of basting tape down the side and fold over making your tube.
- Cut two 1" wide by 2" rear end straps for your spar tubes.
- Cut two 1" wide by 3" front end straps for your spar tubes.
- Using basting tape on the bad edge to position and tack on the straps on the tube ends.
- You can close up the rear end strap now.
- Do Not sew the whole tube up at this point as you'll be sticking the tube on the top seam in the next step!
You can see here how the finish front edge is going to look after you close it up. All the edges are on the inside of the tube.
- Use baste tape to stick the inside mid keel to the bottom side of body.
- Then another full length of baste tape and stick the tube on that.
- Stick on your back tail strap on top of the tube.
Closing up the tube is done by starting at the front of the tube and pulling it inside out as you sew it all together. Note while doing this you do not have the big edge of the tube basted on. That would not be easy to do with the kite tube inside out. Just take it slow and don't worry about wrinkling the material as you can't avoid that here.
Now you can fit in your .125" rod.
- Wear gloves and eye protection when cutting and handling FiberGlass or Carbon rods.
- Mark the rod at 39". (39" should work fine if your finished tube length was 39")
- Cut at the mark by putting rod in a vise and using a hacksaw with the fine 32T blade.
- Be sure to use plastic end caps on the rod to prevent wear which will happen quickly if you have a sharp rod end against the webbing!
- Move to the side the webbing and you can insert the rod in.
- Switch over to a straight long stitch.
- Note you will need to change to a narrow sewing foot to sew that close edge.
Don't go overboard closing up the front webbing cap. Just one simple stitch is better as if the rod should break or you want to change to different rods say some exotic light weight carbon tubes then undoing the stitching will be easier.
Here is a view of the back of the spar tube which is closed up. The tail strap also is there so it all gets joined together which surely gives it a good strength. The front and back tube areas are the thickest parts to sew on the entire kite and some light weight machines might have problems here. If that is the case hopefully you can just hand crank it through.