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Rudder fiberglass fit?

kjowen

Well Known Member
I have been tinkering with this step now for about 4 months...
I have seen the beautiful work on many -8's in this area and I am just trying to get mine to the point that it has no gaps...
Please take a look a the current status of this assembly and any suggestions would be appreciated.
Thank you

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I cut the forward part to be parallel with the hinge cutout on the rolled leading edge, rather than extend the skin line along the bottom. Then bent the spar flanges a bit more to align with the fiberglass. That simplifies the fit a bit.

I left the horn cutout as is, since the horn reinforcement covers that. The old planes 4/6) are wide open there. You can see clean through! So, just squared up the cutout and moved on.
 
Rudder cap

That drove me nuts. I finally cut away all the areas where it bowed out and applied several new layers with a scarf joint. I also didn't slot mine the way Vans shows. I slotted it so it slides on from aft. Inside forward area was filled with a small block of foam and a layer of glass to stiffen and seal. It's basically sealed against the spar and the angle. Inside a section of Vans conduit was bonded as a pathway for the wire. Two 4-40 nuts were floxed in place on the aft end for the beacon.

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Y not put a piece of foam to fill the triangular section of the brace, tapering back to streamline that aeria. Then just glass over it, wala speed fairing. As for the fwd section just bend the edges of the spar. Then pop rivet to hold in place then flox and sand to look good.

RD
 
On my RV-7A, I ended up bending/curving the bottom corners of the aluminum flange a little to allow the fiberglass to sit better.
 
Before fitting the fibre glass

1st thing I would do is replace the rivet with the multiple smiles in the picture bottom rudder forward left side

Not looking forward to the fibre glass work

Rob
 
1st thing I would do is replace the rivet with the multiple smiles in the picture bottom rudder forward left side

Not looking forward to the fibre glass work

Rob

From the looks of those smiled rivets and the damaged structure it must be a very difficult place to rivet.
 
Ken, see attached.

No real value in closing the rectangular opening. If you do, scarf the new glass to the existing glass, all fabric plies, no flox. I'd suggest the parallel lines approach.

At the front, cut away whatever doesn't fit and scarf new glass.
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Not a big fiberglass fan but I did learn that if you don't like the shape, cut it back and put in a filler piece. Fiberglass bounds to itself pretty good.
Trying to force cured fiberglass into a different shape is never going to be the solution.
 
How do you intend to attach the fairing to the rudder? With rivets or screws?
If you want to make it removeable you have to plan for that in the rudder horn area.
As for the rectangular area, I typically save pieces of the fairing fiberglass and after trimming to fit, just bond it onto the rudder and it matches the fairing. Just looks like a skin line between the two.
On the leading edge curved piece, I would cover the rudder pieces with packing tape or a release agent and use flox or cloth on the under side of the fairing, basically thickening the fairing at that point, and then sand it down to fit. You could also try to heat it up and bend it around but you would need a mechanical fastener to hold it in place since the cured FG has a memory and will eventually want to spring back out.
The gap from the bottom of the rudder skin to the top of the front piece of fairing, I would leave alone. You will never see that anyway.
All of the previous ideas are also good ones, depending on how you want to do it.
Good luck
 
The tip uses polyester resin, so you can shape it with a heat gun to match the underlying structure. No need to bend the spar flanges.

I converted mine to a two piece fairing, using blind fasteners and EC2216 structural adhesive to fix the aft end in place. Made the nose removable for maintenance access, using #6 screws and plate nuts.
 

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Rudder Cap Better Fit

Adding to this thread, I just followed Dan's recommendation of removing then scarfing glass to alleviate the bottom rudder cap fit issues. Really, it wasn't that diffucult and the fit will be much better. Still need to use micro and sand, but the initial layups seem good. Thanks Dan and others that contribute these techniques!
 

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Easy Peesey

For me, in the third picture about that gap, i just heated up the fiberglass and bent it in to match the rudder. QED> I am not building a show plane, just a fast plane.
 
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