I have two damaged wings from two Four Star .40's. The first Four Star the right wing panel ripped off after trying to pull out of a full throttle dive and the fuselage was toast. The second four star the left wing panel was demolished after hitting a pole. So on both of the remaining wing panels (1 left & 1 right) the wooden wing joiner is still glue'd in. How can I get these out so I can try to make 1 good wing set out of two bad ones?

Getting them out is next to impossible.

What I would do is to cut the two bad halves off, remove the bottom, center sheeting from the two good halves, and sandwich the 4 spars with some 1/8" ply on front and back. Then re-sheet

Next to impossible. You could cut the wings in half, discard the bad half and then spend eternity trying to remove the brace with a Dremel tool.

You don't, Just leave it in place and double it up with a second joinner. I faced the same issue with a 4*60 wing that I aquired. Some one had started the kit and at the point of joining the halfs together, they got baddly screwed up. After a while, I just sawed the wings in half. I cut new center ribs as there wasn't much left after the saw job. I open up the bottom sheeting and then using a soldering iron, heated and cut away any epoxy along the edges so the new brace would fit snug to the old one. Once I got the root ribs in place, the rest was very easy. Just like joining a pair of ARF wing halfs.

The reason to remove the bottom sheeting behind the brace is that the airfoil is flat there. When you have the two halfs joined and even, the use long sheets of balsa that will span the center section of both wings. This gives you some added strength.

I lost my second 4*60 with this wing a couple months back. It went in from about 200ft straing down. The fuselage was teeny tiny sticks. The wing was indented about 1 1/2 ' where it pushed forward into the fuselage in the crash. A couple of the little 3/16" spars snapped, but the wing was basicly intact. I'm not sure if I would trust it to fly again, but I haven't junked it yet either. That repair will be as strong as your first wing, maybe even stronger.

Don

If it was glued with epoxy, you can use a heat gun to heat the joint. At around 400~450 degrees, epoxy turns into goo and lets go. I have removed a "oops" firewall glued in with epoxy that way. Patience, it takes awhile to get the joint hot.

Here I beleve is whats being described. Its a wing I deliberately cut in two to change some angles with a ply doubler being installed over the abandoned original and the rib filled in agine up to the new doubler.

John

Just cut it off flush . Cut away the sheeting top and bottom, front and behind, near the spar.
Cut the slots into the center ribs for the jointer.
Glue different joints to the front and back of the spar. Use clothe line clips to clamp the jointers to the spar.
Sand the new jointers flash

Alter the diehedral if you want to. Just use tri stock (center ribs to jointers ) after re angling the center ribs accordingly
Then just resheet.

I'd cut all the sheeting and re-sheet like Campgem said becuase I hate sanding fiber glass. Plus I think it's just easier and
the final finish will also look much better. Plus I'd add another jointer to the rear spar just for kicks.

Cut the center Alignment tab. Install a center piece dowl.

Same thing happened with me and my Twinstar.

there is no way to get the full 8 " or so of the jointer hot enough to be able to pull it out. Your balsa will scorch and may go up in flames. The glue joints around the jointer are going to be destroyed in the process. It just flat will not work.

THe heat though is a good way to get the fiberglass tape off the joint. You don't need the 400+ degrees, at 250 epoxy and CA starts to break down. At 350, Epoxy starts emitting hazaderous fumes. You want to get it just hot enough for it to start into a plastic state so you can scrape and pull off the bond. Actually boilling water is hot enough, but it doesn't do the balsa any good.

I had to remove a lot of epoxy slop from the wing I salvaged. I used my covering iron on a lot of it, but you can only head up one or two square inches at a time and still be able to work the softened epoxy. As you move on, it hardens right behind the iron, so heat and work fast.

Don

Im not sure if I want to risk having a crappy wing joint so I may just buy a new wing set from Sig. Im still pretty new at the hobby and don't really have the help from someone more experienced with this sort of repair. It sounds like I need to buy some tools and the way I am I will end up buying more tools and supplies to fix it when it will probably be cheaper to just buy a new wing set.

Come on guys its not rocket science..... chop off the wing joiner, add another next to it and use epoxy..... Believe me a one side wing joiner with epoxy will not come off even if your plane is torn to shreds.... Epoxy usually holds even its a little piece, its easier to break with wood coming off than at the joint point....

Also its a trainer/sport plane not a 400mph jet..... I wouldn't do this to a f16 jet but to a fourstar its a no-brainer ??

How about cutting the wing or wings in two and drilling a hole or two into the joiner and putting a carbon fiber spar into them?????? Add some blocks on the back, towards the rear of the wing and put two carbon spars or what ever. If you glass the wing halfs all the way around after joining it should be good to go.

No it will not be cheaper it will be very expensive in the long run and it even could cost you the hobby. Do not be just another crippled arf'er who can fly fine but can not even do the simplest of chores on his own airplane because he is afraid to try. People who do not make an efforrt to learn the building basics soon disappear from the hobby.

Like one poster so eloquiently stated: This is not rocket science. Its a very simple procedure and you have been presented a number of slightly different ways to proceed along with detailed photos, most will work just fine.

So dude you need to first:

Muster up some courage

Start your tool collection now, the tools will last for a thousand repairs or builds, a replacement wing will only last to the next crash!

Start building your lumber supplies: a little balsa and a little ply

You have plenty of both moral as well as tech support right here on the forum if you are not shy about posting.


I wish you well

John

Don’t worry about a dihedral brace. Get some sheeting and make doubler ribs for the center ribs that can be sanded for the dihedral you want and a tight fit. After the wing is epoxied together, fiberglass the center section with 2” – 4” wide fiberglass. It’ll hold up to anything you can dish out to it. I’ve built many planes that have had the center section glass and no dihedral brace without any issues at all.

Hogflyer

If you buy a wing set, you are going to have to put the sides together anyway, so scratch that out of your list of problems. Your only problem is getting a space to glue the new jointer into next to the old one. And, a bit of covering to finish things up.

Tools you will need to cut the wing in half at the joint. A hack saw and a razor saw. On the damaged side of the joint, mark a line 1/8" away from the glue joint between the wings, toward the bad side. Use your razor saw and saw through this line all the way around the wing. You will cut through the surface sheeting and the you will need to use the hack saw to cut through the spars and lE and TE, and the diherral brace.

Once you have the halfs seperated, use some carpet tape, and tape a full sheet of sand paper to a flat board. Position the wing about to the dihedral angle for a half wing, and sand the cuts flat. Stroke the wing across the sandpaper only one way to keep it straight. If you push pull, you end up with a high spot in the center. Do the same for the other half. You should now have two half that are ready to join. At this point, you can open the bottom and make a new slot for the dhideral brace. Glue things together and then close the opening with new balsa, I would get 3/32" for this. Sand things smooth and then, you can seal down some new covering over your repair.

I doubt that your wings were joined with fiberglass tape, so just ignore that part of the previous instructions. You can use clear heavy packing tape as a good fuel barriar and then pickup some Kylron FUsion plastic paint from your ace hardware store, that is a close match to your covering, and give the tape a couple light coats.

The only issue I see that you may run into is that your wing hold down dowels and screws my end up a little two wide by 3/32" inch. This won't be a problem with the screws, just use some sand paper glued to a wood dowel and sand the holes in the wings to the joint. You will only need to go about 3/64" on each side. For the dowels, I would do the same thing, but on the fuselage former and this time sand them out the same amount. THe reason for doing this is you are going to end up with a wing that is 3 /32" longer and that extra length is in the middle.

Total tools you will need. A Razor Saw, A hack Saw, and Xacto Knife, and some sand paper. Materials, a 3/32" sheet of balsa, A new dihedral brace, some clear packing tape and a can of Fusion spray paint. $10 to $15 bucks top for everything.

Don