nauticom

I'm in the proces of building a Ziroli GS Corsair. As you all may know the gull wing is often a challange to build right and true.
I find myself with an error in the accuracy of one of my wing rib's allingment to achieve the proper wing dihedral. As a result I have a gap of 1/8 inch on the bottom of the joint where the one outer wing panel joins the gull wing center section. This occured because one rib was not true vertical to the building board during construction frame up. Thus when I went to mate the outer wing section to the center section, I had a far to small dihedral. After filing and fitting, I can get the correct dihedral, but I end up with a big gap on the bottom of the joint. The gap is pie shaped, if you will, so I'm looking to build up the gap with material prior to final joining of the two wing sections.
I'm quite concerned about joint strength at this critical location of the wing.
I am now ready to either mix up some epoxy resin and micro-balloons , iron on Monocote to one rib, spray mold release on it and then pour in the above mixture into the joint and let set, then break alway.
The other idea is to use exopy resin and a saw dust mixture and do the same thing--the thought being that that combo would be stronger?
I do not want to wait until it is time for final wing assembly and do something. I would like to get it fixed now.
Need your expert help and advise.

PS:
I thought I was a very careful builder, lots of experience, but this one got away from me at a very bad location and you cannot hide the wrong dihedral.

Thanks,
BobM

Live Wire

nauticom
Did you think of fiber glass cloth and epoxy, fills gaps and is strong enough for stress areas.

pub

You could take a peace of ply,longer than the rib sand it for the taper you need and then cut out the rib shape and epoxy it on. just a thought pub

SoCalSal

My Feedback: (16)

Hey I feel the same way about my building style. I have the same problem on a wing panel on my Stearman. It has a gap just at the mating point to the fuse. It was caused by a oversite on my building of that panel.
What I did is mount the wing to the fuse, makeing sure it was aligned correctly. I then pulled wing back from fuse justenough to get room to work on it. I then slipped in a scrap piece of balsa to fill that gap. Then pushed wing back up against the fuse and started sanding the filler piece till the gap was gone. I had to sand both a wedge shape to fill the gap and sand the taper cord wise to make the gap go away. It will hurt nothing and will never bee seen after covering.
One thing you have to remember when building is that depending on the wood,weather conditions and plans you will almost always have some differiances. My instrucctions even state this. Don't get all worked up over it. It is just a normal thing in building. I use a product called "SuperFill" you can get it from F&M En terprizes. It is a two part epoxy filler used on full scall planes to fill in imperfections . It is very light and sandable, easy to work with. II always keep it on hand during a build as I manage to get many small dents and chips in the balsa during construction.
A small gap is nothing to worry about as long as it doesn't change the dihedrel in the panel. as they say " sh*T happens" and it is not worth loosing sleep over. Heck after you cover and paint the panel you most likley forget it was ever there. As builders we see every little mistake we make. But all others won't see it unless you point it out.

nauticom

Thanks guys:
I'm not going to fight it. I will set the correct dihedral and fill the gap with epoxy at time of assembly. I will likely epoxy 3 or 4 oz glass over the joint prior to fiberglassing the wing.
Thanks for your inspiration.
BobM

aerowoof

basically what you need is a wedge.much like airleron or trailing edge stock.you say the widest part of the gap is 1/8".then cut a blank rib out of 1/8 balsa.all you want is the rectangle shape,correct length and width.you will need a piece of 1/8" music wire and a piece of sheet metal about 20-24 gauge would work with one straight edge.sandwich the blank rib between the wire and sheet metal.use tape or clamps to hold hevry thing in place while you sand the balsa sheet to a wedge shape the wire and sheet metal will keep from sanding too much away from where you need the thickness ans will give an uniform edge.after you get the wedge glue it to the outer rib and cut to shape then when you join the outer panel the gap should be gone.