Aluminum backing on cowl needed?

[rogerh12]

On my other plane, I had an aluminum strip on the inside of the cowl where the nutplates would mount, to keep them from pulling though the fiberglass when the cowl was screwed back down.. Is this common on the Kitfox cowling? Are folks having issues with vibration or torque pulling the nut plates through the cowling sides?

[efwd]

Hi Roger.
I have a SS7. I have no place on the cowls or wing tips that have a nutplate installed onto fiberglass. The closest thing to a nutplate would be the cowl fastener female half. It is countersunk riveted to the fiberglass cowl from the back side of the cowl flange. When the male half is mated then the two halves are sandwiching the fiberglass cowls together so it isn't like the rivet heads are susceptible to being pulled through or anything. I hope that makes sense. If the kit manual has you rivet anything to something soft , like wood, it will say to use a reinforcement washer on the rivet.

[jrevens]

Hi Roger,


Like Eddie said, I don't think there is any problem with nutplates or Camloc receptacles "pulling through the fiberglass". There is fairly large surface contact area and no relative motion between the nutplate or receptacle and the fiberglass, if installed properly. I did bond some thin strips of aluminum to the inside of the bottom cowl side flanges on mine, but only because I wanted to stiffen them against the flanges being pushed inward while engaging/seating the Camlocs. On my cowl those flanges were a little too thin and flexible for my liking.

[airlina]

The only problem I have run into after 15 years of flying my Series 5 , is the camloc holes enlarge slightly and allow the male end of the camloc to fall out whenever I remove the cowl. This usually end up with a lost fastener as it falls into the grass or disappears under the workbench. Just this week I added a backer to the few that where problematic. Bruce N199CL

[Clark in AZ]

Anyone use the piano hinge technique?

https://www.youtube.com/watch?v=B9ILDKgKbbM&t=0s


Clark

[jiott]

Airlina, why don't you use the internal star washers that come with the Camlocs. They hold the male piece firmly in place. I installed them on mine after a few incidents as you described-no more problems.

[rogerh12]

I must have been thinking about the camloc holes enlarging on my previous fox, screws and nutplates should hold the cowl much tighter, keeping erosion down on the glass. I did use piano hinge on my Sonerai, it worked well and you could open the cowl quick, but it was a two piece and you had to remove both cowls to check everything. The fox and be checked mostly by just removing the top front cowl.




The only problem I have run into after 15 years of flying my Series 5 , is the camloc holes enlarge slightly and allow the male end of the camloc to fall out whenever I remove the cowl. This usually end up with a lost fastener as it falls into the grass or disappears under the workbench. Just this week I added a backer to the few that where problematic. Bruce N199CL

[airlina]

Airlina, why don't you use the internal star washers that come with the Camlocs. They hold the male piece firmly in place. I installed them on mine after a few incidents as you described-no more problems.
Hi Jim, I did use the smaller internal washers that worked for a long time but eventually even those started slipping thru the holes on a few of the fasteners. Looks like the star washers are a bit larger so on my next Spruce order I will give them a try-Thanks for the heads up.

[beeryboats]

The only problem I have run into after 15 years of flying my Series 5 , is the camloc holes enlarge slightly and allow the male end of the camloc to fall out whenever I remove the cowl. This usually end up with a lost fastener as it falls into the grass or disappears under the workbench. Just this week I added a backer to the few that where problematic. Bruce N199CL

I have to laugh, mine just did that for the first time. Lucky for me I was on concrete.