Leading edge build up?

[Avidfox]

Hi,
Can anyone out there share there experience or plans on how The mod 4-1050 wings are built? I recently had a trailering mishap! My right wing leading edge is damaged. There is no damage to the spar which gives me hope that I don't have to replace the wing. Any info or help will be apreciated.
Save Flying and Trailering!
Dave
Yakutat

[Av8r3400]

If you can post a photo of your damage we may be able to help you assess the extent of repair needed.

[Paul Z]

A picture would be required to see how large & extensive the damage.

[Jfquebec]

Suggestion...maybe cut it more square ...glue foam block...sand it and put superfill putty...


Jf

[avidflyer]

There is a plastic piece that is glued to the front of the spar. It projects forward 1/2" from the front of the spar. That being the case, if your dent is 1/4" deep, then it's doubtful that you would need to replace the wing. As others have said, a pic would help. Just ran down to the basement and grabbed a Kitfox 4 manual, and scanned the page you asked for. Hopefully this will be able to give you a good answer about replacing a wing. Jim Chuk

[dholly]

So long as the spar was not affected, the damage is minor and cosmetic only. The previous owner of my Model 4 had a custom trailer built for it so my purchase agreement included delivery. Unfortunately, he damaged the leading edge on one wing loading it up for the trip ughh. Fortunately, damage was limited to the fabric and PVC extrusion only. I found it to be a rather straightforward repair and quite simple really. Here's what I did...

The problem...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137625749_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137625749.jpg)

Prepping the area...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137801077_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137801077.jpg)

PolyFiber manual says don't use Bondo because it is heavy and retains moisture, I used this 2-part filler instead...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137918206_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180137918206.jpg)

Filler on and rough sanded...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138293348_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138293348.jpg)

Gluing the patch fabric on with Poly-Brush...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-131801384842_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-131801384842.jpg)

Patch after heat-shrinking and 2 coats Poly-Brush...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138713144_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138713144.jpg)

After a couple coats of silver UV Poly-Spray and wet sanding...

http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138859412_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_10_2011/post-53-13180138859412.jpg)

After spraying on some PT136 Lemon Yellow Poly Tone paint, it looks half-way decent. http://www.avidfoxflyers.com/public/style_emoticons/default/smile.gif

http://www.avidfoxflyers.com/uploads/monthly_11_2011/post-53-13211132836792_thumb.jpg (http://www.avidfoxflyers.com/uploads/monthly_11_2011/post-53-13211132836792.jpg)

Hope that helps.

[Avidfox]

HI and Thanks to all!
It looks like I need to see if I can get a new piece of PVC that mounts to the leading edge from Kitfox or do a foam/fiberglass buildup. I do know that there is No damage at all to the spar. Its just going to be a pain as she is in Anchorage and I am in Yakutat. I did find that the first rib (The visible one) is cracked.
9917

[TahoeTim]

the cracked rib is scary

how do you know more of them aren't cracked?

[Paul Z]

Crap, now that is a little damage on the Leading edge. I'd go with a new leading edge from Kitfox, that way the airfoil will be correct. It will also be a faster repair versus shaping foam & then fiberglass.

[dholly]

Ouch. Obviously going to be a bunch of fabric work, but it's really too hard to see from that pic just how badly the PVC is damaged. If it's only scraped down it's length and not totally mashed in, I think it might still be easier to use a bit of filler along the length than removing the old extrusion entirely and replacing it. You can use the template Jim posted to cut out a properly shaped squeegee from some stiff plastic and pull it along the leading edge after applying filler. If you're careful, it should go pretty quick and minimize finish sanding (after all, it will be covered by several layers of fabric and tape). That is, of course, assuming the PVC LE is more scraped than smashed in. I'd be wondering about those other ribs. Grab the wing at the tip and try to twist it (LE up, trailing edge down & vice versa) while listening for any unusual tell tale sounds.

[Av8r3400]

Ouch!

With the cracked rib, I'd council for a complete removal of fabric, inspection and repair of the wing with a new leading edge and whatever else is needed. Perfect time for a fuel tank upgrade, too.

[avidflyer]

I hate being negative, but if the plastic leading edge was pulled off, it must have torn both layers of fabric (top and bottom) plus the finish tape that covers the lap of these two layers. If that is the case, I would wonder how well the fabric would stay on when you fix it without pulling all the fabric and recovering the wing so you get the 2" lap of fabric. If it was just a short length of damage, it would be not such a concern, but if the fabric blows off the wing in flight, it (and you) go downhill from there. Jim Chuk

[Paul Z]

I'd strip the Fabrick from the wing, check for damaged ribs, replace the original leading edge, & recover the wing.

[Avidfox]

Thanks again all! Hopefully Kitfox still sells that leading edge. I e-mailed them but no response. Building up that airfoil isn't a problem but I would rather have the original parts.
Dave
Yakutat