Spreaders

I decided to build my own spreaders for the mast since I had a partial role of 19.9 oz, 3 inch carbon fiber sleeve (from solarcomposites.com) left over from building my bow-prod and bow prod receiver, and some uni-directional CF cloth left over from the keel.  I really didn't have any idea how strong these should be, but I got some good advice from some of the people on the i550class.com forum.  


To start, I wanted a nice airfoil design for the spreaders.  The idea of course is to reduce wind resistance, but this shape also has a nice appearance.  In order to get this shape I bought some tapered foam inserts from flyingfoam.com.  These were NACA 0015 shaped.  The standard quick order foils have a maximum length of 36", so rather than ordering a custom shape, I just ordered four 36 inch foils and some shorter fixed chord-length inserts to extend the length of the lower spreaders.  


For the lower spreaders, I wrapped the core with 5.7 oz fiberglass cloth, then covered that with a carbon fiber sleeve, then covered the top and bottom surface with 12 oz unidirectional cloth, and then covered all of that with another 19.9 oz sleeve.  I painted epoxy on the core initially and then on each of the layers that I added.  For the upper spreaders, I did the same thing, but I wrapped the core twice with fiberglass and only used one layer of Carbon Fiber sleeve. 


One of the nice things about the foam cores that you buy from Flying Foam is that they are shipped in the foam that the cores were cut out of.  These "female" shapes are very nice for using as a press after all of the layers of composites are put on and painted.  This avoids having to vacuum bag these things in order to get a very nice finished shape.  So after everything was nice and gooey, I wrapped each of the spreaders in release cloth, then a light plastic sheet and then put the whole thing back inside of the female shapes.  I then put a board on top of the pile and put weights on top of that.  The picture above shows the finished spreaders.  I don't have the exact length that I want them to be yet so they will be cut to size later.  The spreaders actually look quite a bit nicer than in the photo.  The mat look is due to the texture from the release cloth.  I think that I'll varnish these in order to get the nice carbon fiber look.


I was originally planning on mounting the spreaders to the mast with a bracket with a pivot point.  Based on some feedback that I got from Chad on the forum, I think that I might mount them in the shape of a hard V instead of having the pivot points.  


As a final note, these spreaders are extremely stiff.  I can barely get a deflection on the lower spreaders when I lean on them.  The lower spreaders ended up weighing 1lb 4oz each and the uppers weigh 12 oz each.