Question about gluing in the wing

If I cover the entire wing with silkspan and paint, do I need to remove silkspan from the area where the fueselage is? Will sanding off the paint be enough to ensure good joint?

I wouldn't sweat it. Cover it, dope it, and glue it in. As an example, I had a Jr. Ringmaster that got damaged beyond repair (not a flying accident)- this was covered in silk and dope and the wing was glued into the fuselage with thin CyA. I tried to break the glue joint apart just to see how well I had done it. I couldn't with all my strength- the balsa in what was left of the wing and fuse failed- the wing/fuse joint never did. Plastic iron-ons are a bit different matter, but for the traditional stuff- cover it all and glue it in.

john

I have to agree with Jake here, I used to just glue the wing in, covering and all and never noticed a problem. I've since moved to leaving a gap, but not due to any particular gluing problems.

One thing you could try, which come to think of it, I did, is to dril loads of tiny holes along the joint into the wing skin (in my case it was a 1/2" thick balsa rib though, not a skin) so that the glue can seep into the wing.

Normally I just cut the hole as close to size as I can, then keep adding epoxy. This time on my Flite Streak I actually packed the joint with little bits of balsa, and I was really impressed with the rigidity of the joint. I'm also less keen now on allowing aliphatic to fill gaps, as although it is strong stuff in a good joint, it's just a little too brittle if you have 1/16" plus gap to fill.

I generally leave the portion of the wing where the fuse will glue on unpainted except maybe for a thin coat of nitrate to hold the silkspan down. Slow cure epoxy will go through just fine, as will CA. My method of fixing a wing in a profile is to tack the wing in place with CA, fill any gaps with scraps of balsa. Seal the outside seam with Sigment and then hang from the leadouts. Apply 45 min epoxy to the inside seam and warm with a hair dryer until bubbles quit coming out. This means that the epoxy has filled all the voids. Be careful with sealing the outside seam or you will have a line or several of epoxy running down the outside wing. Then you do fillets, or not as you please.

>One thing you could try, which come to think of it, I did,
>is to dril loads of tiny holes along the joint into the wing
>skin (in my case it was a 1/2" thick balsa rib though, not a
>skin) so that the glue can seep into the wing.

Instead of drilling tiny holes, you could also use a pin to prick the area to be glued with very tiny holes.

I've been gluing the wing in place first then covering with film or silkpspan. Covering the wing isn't the problem - it's covering the fuselage and getting around the flaps, pushrods, stab, etc.

I may try my next by covering the components then gluing.

On the last profile I built, I covered the wing first then tried to slide it into the fuselage. Because of the tight fit of the hole in the fuselage, there was no way to get the wing in without damaging the covering over the ribs. I then remembered a trick we used way back when to get a better wing/fuselage glue joint on Ringmasters. I split the fuselage down the wing centerline then clamped it around the wing using tape wrapped around the fuselage forward and aft of the wing. This requires adding the plywood doublers after wing installation, but that didn't present much of a problem. Next time, I'll try adding a thin piece of carbon fiber along the fuselage split line.
Steve