SonexBuilders.net

Looking for tips/tricks on forming aluminum fairings, in particular the Waiex fairing that goes between the stabilators on the aft fuselage. Wondering how to get a smooth bend without having any hammer marks (I'll be polishing.)

If it is like the fairings on the Sonex. I bent the flanges then rolled the rest of it by hand over an 1 1/2 inch pipe. I did nothing to the metal before just rolled and applied pressure. It took some patients bi came out very good.

I cant speak to the Waiex fairing but for the Sonex tail fairings I cut the part oversize and annealed the metal before forming it over a 2 inch metal roller. To anneal it you scribble on it with a sharpie marker and heat from the opposite side with a propane torch until the sharpie dissappear. Let it slowly cool down to room temperature and it becomes much more pliable and less springy. Practice on some scrap first as it is easy to over temp the aluminum and burn a hole in it. I bent the flanges last and trimmed the excess off of them.

Keith
#554

For the Sonex fairings, I cheated. they appear to serve no structural function, so formed mine from 0.016 6061-T6 by hand over edge of table. 3 years in use, still looks like new. 0.020" material is also available from ACS in 2 ft. square sheets where shipping charge is minimal.

David A.

The first fairing I made by the plans didn't fit under the turtle deck. So I made a mock up out of poster board, shaping and trimming until I got it to fit the way I wanted it. Then I transferred every dimension and bend onto a fresh piece of aluminum. I annealed as described earlier and then bent the curves by hand using different sized curved structures ( pipe for small end, and a small bucket for the bigger end). You need to bend the flanges before shaping the curves. My fairing was a bit smaller than the plans called for (narrower at the big end). Hope this helps.
John (Waiex 176)

Anneal, them work slowly over a rounded edge. You will get a perfect shape.

Great replies, thanks. Quick question since I know very little of metalworking, once annealed do you need to work while it's still warm, or do the properties of the piece permanently change (become softer) once you've properly heated it?

It's permanently changed, no need to work while its warm.

Hey all,
On that Waiex tail fairing, any hints on how to get it to fit tightly against the aft part of the turtledeck and still be able to slide it under? I am working in poster board but the geometry is tricky.

Bryan,

Even thoughI had the lowly straight tailed version, the fairing is similar. I used a high tech solution.

A broomstick.