Repairing molded wing tips

[ferradas]

I had a nasty fall on my wing tips and now I need to repair them. I have sanded down to the glass layer, I would like to fill in the creases with something that I can sand out smooth that will eliminate the creases. What should I use? I was thinking of light weight spackle, will this work? Any other suggestions?

[ferradas]

I forgot to mention that I haven't finished sanding the top wing panel in the picture.

[averen]

Those pictures hurt me :(

I would probably go with some epoxy and microballoons. Easy to sand and it won't add that much weight...plus it will be stronger than spackle and less likely to flake off.

Good Luck!
Averen

[F3X]

Oops :)

Continue to carefully sand the area and over sand by 1".
Use some foam safe CA and drip some in the cracks WITHOUT kicker. USE NO KICKER!
The inside skin is damaged as well so the CA will help.

Mix some laminating epoxy and lay up some 1oz cloth in the cracks. If the cloth won't lay down easily because the "V" is deep in them mix some micro/epoxy and fill the "V" almost to the surface then lay on the glass. Let the glass extend the repair by 1" beyond the damage.

Sand the edges almost smooth after the epoxy has fully cured. Fill any lows with epoxy/micro. Wet sand the area flat and smooth. Don't sand past the paint, If you do then you will need to re glass that area.

I wouldn't worry about getting the repair exactly flush with the original skin because the glass at that location is very thin and all you would be doing is weakening the area. You can't scarf splice .003 thick materials very well. Just get the edges smooth and blend in the repair with some primer/filler and repaint.

Take your time and it will be finished in a few evenings

[ferradas]

thans for all the suggestion guys, I felt like since the was the first time doing this, I would take my wings over to my friends house that has experience doing this, here's what it looks like before we final sand and apply paint....... He really worked magic here...This is the bottom tip(the worse one) from the previous picture.

[mattg]

Can you please describe the process your friend used it would be very helpful to know if it differed at all from TC recommendations.

[SteveR]

How did your friend make the repair?

[ferradas]

We used Bondo for the repair, it's found in automotive stores. We first applied a thin layer of Bondo and evened it out with a credit card, it dries in about 30 minutes, then rough sanded, we then apply a second layer and did the same process, by this time it's pretty smooth with very tiny pin size holes here and there if that, this is where the Spot Putty comes in and fills all the tiny imperfections and makes a very smooth finish after fine sanding, this putty stuff dries quickly, about 10 minutes.

Since the tips are not a high stress area, there is no need for applying a glass layer, just paint and your done.

[F3X]

Just Bondo? No cloth, no epoxy. no CA?

Keep an eye out for small cracks in the next few weeks. Some foam and Bondo (Polyester Filler) don't get along so well. Some do. Your area is non structural as far as flight loads but we usually ding them up during assembly or just getting them to the field. aka Hangar Rash.

My gut says that if you flex it you will get a crack at the repair. If not then your "Good to Go

[portfoxdesign]

Ferradas
Don't know if it will help you at this late stage, but here goes. You can buy an expandable foam from a can, its has a small nozzle on about the size of a WD40 nozzle. Making a very small drill hole in the less stress area of the wing, stick the nozzle in and spray some into it.
Once it expands it will provide some reinforcement under the week repaired area.
I have used it years ago on glass fuzz's for repair, It just stops the flex thing happening to a certain point.
Just thought it may help.

Happy flying
PD

[mattg]

Hey PD, can you give us the brand name we can use here in Oz? Is there any chance of it attacking Rohacell or blue foam?

[portfoxdesign]

Mattg
I seen it in bunnings warehouse near the turps and metho, i'm not sure about attacking the blue foam, it was OK with fibreglass. As ususal i'd test it first then have a go at some thing that doesnt matter if you kill it.
I havent tested the sanding on it either, so if your browsing through bunnings at any stage, just grab a can of it to try out.
If i'm there on the weekend, i'll get one myself to try on some scraps of foam i have at home.

keep you informed
PD

[ferradas]

I did apply CA to all the areas before doing the Bondo work, I have thought about laying a 1.4 cloth over the area, I think I'll leave it as it is for now and paint it, if I have problems with cracking, I'll smoothen the surface again and apply a layer of glass.

[ferradas]

Here's a picture of the finished wing tip, I didn't think that I would get the color matching right, it was a hard color to reproduce but that was the least of my worries.