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Building Tips and technical articles. => Building techniques => Topic started by: Jerry Bohn on October 24, 2006, 01:09:39 PM

Title: Trailing Edge Sanding
Post by: Jerry Bohn on October 24, 2006, 01:09:39 PM

I am building my Brodak full body Oriental. I have never found a good way to sand the trailing edge spar on the wing prior to putting on the sheeting. It is a 1/4" sq which needs to be shaped so that when the two 1/16" sheeting is put on, it matches the 1/4" flaps. I thought I saw a way to do it on some forum but the method has escaped my senior mind.
Any suggested methods out there?

Title: Re: Trailing Edge Sanding
Post by: Leester on October 24, 2006, 01:42:39 PM

Well here's one way: First put tape on the ribs to protect them. Lay your wing flat so your 1/4" TE is flat on the board and put a 3/16" rod against the TE and sand that. When you have finished that turn the wing over and replace the 3/16" rod with a 1/8" rod and sand that. that will leave your TE 1/8" at the end and 1/4 at the ribs. after the 1/16" sheeting on both sides you'll match your 1/4 flap.

Title: Re: Trailing Edge Sanding
Post by: Bob Reeves on October 24, 2006, 02:21:44 PM

I use my band saw to taper trailing edges before I build the wing. After it's built a little touch up with a sanding bar is all that is necessary. Get the angle off the plans and tilt the table on the band saw to match. You do need a fence and small feather boards to hold down the trailing edge stock but once you do one you have all the stuff and the next only takes a few minutes.

Title: Re: Trailing Edge Sanding
Post by: Jerry Bohn on October 25, 2006, 11:17:29 AM

Thanks for the tips. Since I don't have a band saw, the sanding rod method will do. I do have the rods of the right dimensions since I have done flaps like that before.
 

Title: Re: Trailing Edge Sanding
Post by: phil c on October 25, 2006, 05:26:31 PM

Jerry, for ease of sanding, use the wire method, but do it to the TE before it goes on the plane.  1/4 in wire or brass tube in front, then the 3/16 and 1/8 behind.  Use a thin, thin layer of Gorilla glue in the joint and you won't have to worry about any knicks or undercuts, it will fill them in.

Title: Re: Trailing Edge Sanding
Post by: Jerry Bohn on October 26, 2006, 12:58:50 PM

Got it, thanks for the tip.
Mabey this plane will actually be built correctly, have made 6 planes and have just just sanded  trail sheeting a bit to reduce thickness which left trail edge a bit thicker than flap.
Planes have always flown OK but now I would like to do it right and see the diffrence.
Jerry Bohn