To Patch or not to patch
 

Hi all,
recently a landed a little harder than what the landing gear could take. As a result, it went flying off the fuse, and in the process punched a small hole (about the size of a quarter) on the bottom wing sheeting, between LE and main spar.
Question is: should I patch the sheeting, or just cover the hole with monokote and forget about it?

It won't look right if you just put monokote over it. Chances are the damage lifted the sheeting a bit also, which will leave a bump. If nothing else though, you'll wind up with a dip in that spot.

I am not too worried about how it looks (it is on the wing underside). As along as the wing is structurally sound...

I did the same thing on a 4*60 I used to have. If the bulkheads are fine, I would cut out the damaged piece up to each bulkhead making a square patch. Cut out the patch to about 1/8" of overhang on each side and iron in place using matching covering. You could barely see it unless you were looking for it on the plane I did it on.

If you don't think there is any structural damage underneath then a small patch is probably good enough .. It won't be perfect but its okay to love your plane with warts ..After all its probably going to get more and if its not a scale show plane just fly it and enjoy ..

It should be fine. I would however put a round patch over the hole. A round patch will not show as much as a square patch. The sheeting is really not hard to fix either. If anyone is interested I do mine like this: Cut the hole out to a smooth edged square. Now slowly and carefully cut down a piece of balsa that will closely fit the hole. It does not have to be perfect. It should however be slightly thicker than the old sheeting. Fit the patch in the hole and tack it with thin CA. Make sure the grain is going the same way. Now the patch should be tacked in place and slightly higher than the old sheeting. Now with a sanding block and fine paper slowly and with slight pressure sand the patch. What will happen is the fine saw dust will start to fill in around the patch and fill any voids between the sheeting and the patch. After you get a little build up of saw dust. Take a bottle of thin CA with a CA tip on it. http://www3.towerhobbies.com/cgi-bin...?&I=LXK295&P=M Slowly drip a little thin on your saw dust and imediatly wipe away the extra with a paper towel. Immediately start sanding again as some of the glue will still be wet and catch the saw dust. Repeat the process until the patch is level with the sheeting. When you are done you will have a perfect patch with the fine sawdust filling in any gaps between the patch and sheeting. This is fast and easy once you get the hang of it. It also is strong and smooth. It will leave CA on your sanding block. I like to use a bar with the sandpaper stuck to it.

David

I am not too worried about the look. It is on the bottom side of the wing, and the plane is not exactly a hangar queen. To patch sheeting I have used in the past a similar technique, using little strips of balsa sheeting CAed to the sides to provide a surface over which to lay the patch. However, your method seems even faster...
Alberto

I understand Alberto. Thankfully you are not like me. I can't stand it if it's not fixed a certain way no matter how the rest of the plane looks. It's a sickness :-)
I have done as you said on curved areas so the patch will make the bend.


David

Sorry ululi, I missed the part where you did mention the sheeting. On my 4* the bay is not covered by sheeting so just a patch using ultra cote was doable. I would do as others have suggested.