Skybolt Fasteners

[Mark C.]

On my 9A building going with Skybolt for the firewall cowling attachment. The spec. states to have the flanges at 3.5 centers that seems like a lot of hardware upfront, is anyone using different center line spacing?? Would appreciate any pictures.. Thanks, Mark C. IL location

 

[N15JB]

On my -10 upper cowl I used 5" spacing. Works fine.

Jim Berry
RV-10

 

[TX7A]

Mark,
I used a spacing of 3.625" on my fasteners. Although I used a different brand (Milspec), I think they all work out about the same. Here are the instructions that Milspec provides as they relate to RV's. They recommend 3.5" to 4.25".

Good luck.

 

[Vlad]

On my 9A building going with Skybolt for the firewall cowling attachment. The spec. states to have the flanges at 3.5 centers that seems like a lot of hardware upfront, is anyone using different center line spacing?? Would appreciate any pictures.. Thanks, Mark C. IL location

Good spacing. I did the same.

 

[JVolkober]

I used 3.75 inches across on the firewall top cowl intersection. I am getting some significant "pillowing" between fasteners due to the fiberglass glass heating and the air pressure under the cowl pushing the cowl flang up. Has anyone experienced this and if so what did you do to correct the problem?

 

[TX7A]

John,
Some builders add a couple of layers of glass parallel and offset to the cowl edge. ie, the layers need to be placed such that it doesn't add to the thickness where the firewall flanges & cowl over-lap. This should add some stiffness to the cowl & help the pillowing problem.

 

[Greg Arehart]

I adjusted the spacing to be symmetrical, but it is about 3.5" and I do get some pillowing. I probably would not go much larger. To minimize the pillowing, one might add a small stiffener to the inside of the cowl, perpendicular to the cowl surface.

Greg