Looking for Advice on repairing balsa.

[plug&fly]

I would like to seek advice from some of the gurus out there on the best way to repair balsa damage.
1st question: What type of glue best to use for repair on wing ribs?
2nd question: What technique should be employed?
3rd question: What type of covering to use and where is the best LHS to get them?
Below are some of the pics showing the damage caused by a failed elevator. They show only the wingtip damage. I will post pics of other parts that were damaged later.

[plug&fly]

If I want to redo some planking on the fuse and wings, what glue is best? Can I use epoxy, albeit thinly, to secure the plankings? Or is there a technique for doing this?

[bigfilsing]

the problem is balsa is so soft....... If i were you i try to cut out the damaged component then glue it together with CA ...then trace around it onto some 3 mm ply wood then rebuild the wing. The additional weight will hardly be a problem


Cheers and good luck

[Ghostfit]

Chegu, ...try and replace as much of the broken balsa as possible (ie: cut out new pcs from a raw sheet) and use medium CA. ...try and think like a carpenter.

Epoxy on balsa is too heavy and not necessary unless the parts are under very high loading.

[bigfilsing]

And if you decide to piece the original back together and want to be sure it's strong again you can always CA a cocktail stick or sate skewer ( bamboo) along it's lenght

Good luck

[Ghostfit]

And if you decide to piece the original back together and want to be sure it's strong again you can always CA a cocktail stick or sate skewer ( bamboo) along it's lenght

Good luck

...if you just want a hack job, go ahead !

After repairing, the model should looks like no repairs was carried out ! ...i.e: good as new !

[bigfilsing]

...if you just want a hack job, go ahead !

After repairing, the model should looks like no repairs was carried out ! ...i.e: good as new !

Completely agree but considering it's "in" the wing the structural integrity is of greater importance.
Ideally you could get the factory to send you a new piece but an effective cheap repair isn't that difficult

[gEcky]

Completely agree but considering it's "in" the wing the structural integrity is of greater importance.
Ideally you could get the factory to send you a new piece but an effective cheap repair isn't that difficult

From the pic, the damage is just on the ribs, not any load bearing structure like the main spar. Ghostfit's method is correct. Further, the damage is towards the wing tips...strength is not so critical, maintaining shape of airfoil is.

Chegu, helps if u can get your hands on the plans for this model.. else got to tace out the ribs...

[joe yap]

Ribs are not load bearing structure. They are meant to achieve desired airfoil profile on the wings. Medium grase balsa will do the job. Keep the wingtips as light as possible. A heavy wingtip can cause funny flight charateristics with all the inertia.

[bigfilsing]

Providing the other wing is ok you could make paper patterns of the top and botton profile and use these for the outline (minus the covering thickness) of the replacement piece.

Good luck

[plug&fly]

part 2

The part where the the wing is attached to the fuse was partially destroyed. The pic shows the part of the leading edge crushed to many pieces and totally unuseable. I glued the tongue back with epoxy but the leading edge is gone. I was thinking of replacing the missing leading edge with a carbon tube and rebuilding the D structure of the wing using 2mm balsa sheet. What do you guys think? How should I do it?

[plug&fly]

Actually I have already done the repair....too impatient to wait for replies. None the less, I do appreciate your help and please keep them coming. I am sure others reading this thread will also learn. Just to keep you updated. I have redone the wingtip albeit sloppy and I could not find the right covering for the repair so I just grabbed what I had and the finishing is regretfully much undesirable. Maybe in future when I can find the right covering I might redo it.
The spar was epoxied hastily and kept straight by a balsa truss(I am not sure what you call it) and tip itself is reinforced with a 2mm balsa ply; not visible as it is on the other side of the tip in the picture. I should not have listened to the little voice in my head but should have waited for replies. I will exercise some patience in the next repair session cos I still have the fuse to repair.

[gEcky]

I posted a thread on a similar damage near the wing root:
http://www.daddyhobby.com/forum/show...light=spitfire

[plug&fly]

thanx bro