How to fix a over-sanded airfoil
 

Hello all,

While sanding the leading edge of the Sig 4* 40 kit, I used the Great Planes 11" Multi sander, unfortunetly while sanding I moved the orientation of the sander slightly which caused the change in airfoil.

Here are pictures of the wing ribs, the bottom of the wing has this problem.

I would like to get your ideas about fixing this problem, can I use a balsa filler with some thin CA to fix it?

Since this area will not be sheeted it will look bad under covering, looks like biten by a shark.

How to fix a over-sanded airfoil
 

another picture.

How to fix a over-sanded airfoil
 

Hello Cobra 78,
You could glue 1/16th balsa cap straps to the top of the damaged webs, then sand back to the original airfoil shape. Hope this helps.

Regards,

Pat

Cobra78.......
 

.........I'm like you and want my planes to be perfect before covering, however, this can't always be accomplished. In this case, I would just cover it as is. It will not effect the flight characteristics and it's on the bottom of the wing where it won't be as visible. Just strike this up to experience. To fix this would take time that could be used on covering, or better yet, FLYING!

Good Luck

How to fix a over-sanded airfoil
 

Both Pat and Ed's advice is good!

I would add balsa to the ribs, though, and then sand to get the correct shape.

HOWEVER! The unsheeted 4* wing LE is utt-bay ugly anyway, so you might not notice if you leave it as-is.

Your choice (but it really might not be much work to do the fixin')

Shark Bitten Ribs
 

Cobra 78:

I suggest that you move on. By the time you get your airplane covered, set-up, and a successful maiden under your belt you will have long forgotten about your "Shark Bitten Ribs".

How to fix a over-sanded airfoil
 

Thank you all for your suggestions, I will look one more time tonight and decide on whether I will go into fixing or not. Nobody mentioned balsa filler with thin CA as an alternative. It seems like it is not a viable method. Thanks to RCU, I learned this quick. I did not used balsa filler before didn't know whether it will have the strength.

This is my first kit, overall the plane come up good, I will post the pictures when I am done. It is an easy build kit definetly.

And this is definetly an experince for me, while sanding the LE, I will make sure I don't sand the ribs again,

Thanks,

How to fix a over-sanded airfoil
 

I'll mention balsa filler!

Those dents are way too small to worry about filling with balsa.

Get some "Elmers" wood filler at Walmart and schmear it on. Let it dry and sand it smooth.

How to fix a over-sanded airfoil
 

I have the Hobbico HobbyLite balsa filler, will it work or should I go with the Elmers wood filler?

Do I need to add some water to the filler the directions says so, and recommends thin CA for strength?