My UH12R : Lift Duct

Construction of the lift duct

After skinning the bottom, next was the construction of the lift duct. The actual duct was made by wrapping 1/8" ply around two plywood disks. The duct lip was constructed by forming styrofoam into a shape that pleased me while clinging to the ambiguous description in the plans. A belt sander was used to form the styrofoam. The plans called for blue, closed-cell, styrofoam which was $25/sheet compared to white bead styrofoam at $15/sheet. Budget tight... white styrofoam cheaper... White styrofoam it is! Kind of made a mess but came out okay in the end.

The duct was then 'glued' to the styrofoam using that canned expanding styrofoam. Works great and fills gaps that might have occured in the mating. At this point the duct was just hanging off the styrofoam and had no other support.

Oh yeah... that rope hanging down attached to that green cable was where I decided to store the thing. Hanging from the ceiling of my garage as seen in the pic to the right.
This is a view from the bottom of the duct after cutting and fitting 1/8 plywood from the bottom of the duct to the main stringers and rib 3. This serves to give the duct support. The pulley apparatus I use to store the craft also serves to support the craft for jobs like this.
The plywood strips where then fiberglassed to each other, rib 3, and the main stringers. In this shot, notice that the landing skids are in place and the seams on the bottom have been fiberglassed to seal them against water. Also, note the inside skirt attach strips visible here.
Next is the attachment of styrofoam blocks around the outside edge of the duct to serve as the rest of the duct lip. Then the inside of the craft was painted to protect it against standing water and the flotation jugs were installed.
The top of the nose was then glued and stapled over the lip and the lip was sanded smooth. After the lip was sanded, the disks were kicked out. It's not perfect but I think I did a pretty dog-gone good job. :-)
Finally, I Installed the lift motor mounts and the air splitter and fiberglassed over the styrofoam.