What is the easiest way to build up a wing tip that has been ground down due to a less than spectacular madien flight. The wings are foam core balsa sheeting and .75 glass over. I need to build the area up to get the airfoil back so I can reglass and repaint.


JohnVH you should have some great ideas since your a body guy.

Well, working on wood is a little different than a steel car, but fill it with some body filler, or if its not too deep some glazing putty, you can either put a layer of glass back over that or just get it smooth and prime it up and finish.....

Not sure how an airplane body guy would do it though!

Been there done that....

I glue a chunk of balsa to the wingtip right across the angle the runway sanded in the tip, use a big enough piece to block sand the shape back. Then glass and paint as needed.

On my F-15 I have a set of those Goldberg wingtip skids mounted at the wingtips. I have replaced them a couple of times. Sure saved a lot of work.

Yeah. Cut away the affected area, and replace it with medium balsa. Block sand it, then hit it with finishing resin, or resin and cloth. It's actually LESS work than trying to do it with a whole lot of putty.

While these are great responses, I think I didn't clearify myself. The areas affected are more of a road rash type of repair. Airfoil is looks as if it's only changed about 1/16th of an inch or less, not major chunks missing.

However for future mishaps I will use these for sure.

Then try just filler, sanding, and then hit it with the finishing resin. Goes pretty quickly. Just did the same thing on a plane of my own. It happens.
Doubt if the 1/16" is going to affect anything, flying wise.

be careful if any of the foam is showing, some of the materials mentioned will eat the foam away.

Matt

One of the best Epoxy-based fillers is Superfil which Aircraft Spruce sells. It's two part and very light. You can use it to rough in areas like fillets or damaged areas and then fill in with glazing putty and primer to fill in any small holes. Superfil takes 8 hours to dry. If you have a real small area to fix as I get from your message states and there is no foam showing, I would seal off the area with CA or epoxy and then fill over it with spot putty or similar.

Michael

You can mix milled fiberglass in with your Epoxy for a very strong bond/fill. My favorite is the Duraglass, or the 3M Marine High-Strengh Blister Repair. Both of these used short strand fiberglass mixed in with a special high strength body filler. If you ever scrape again the damage will be superficial. To protect your paint use a strip of adhesive backed velcro (fuzzy side) on your tips. They will take an impressive amount of abuse and when they wear down, replace them with a new strip.