Cowl fastener question

[Tony Spicer]

Disregarding the additional time it would take to remove the fasteners, what's the downside of just using 8-32 anchor nuts, SS Torx screws, and flush finish washers to attach the cowl ? Intent is to use them just across the top of the cowl and inboard sides of the intakes, with hinges per the plans everywhere else.

thanks,

Tony, RV-3B 11395

[Mel]

This configuration has been working great on my -6 for almost 14 years. However, you want to use the screws across the bottom too. The hinge "eyes" will not hold up to the pressure and vibration. Hinges work fine on the vertical and horizontal sides.

[Kyle Boatright]

What Mel said.

I have 10 #6 stainless steel screws across the top of the cowl on my -6, and 8 #6 and 2 #8 screws along the bottom of the cowl.

I have the hinges running vertically on the cowl sides and horizontally along the cowl split line.

No problems over 6 years and just under 450 hours.

[Tony Spicer]

Thanks for the input, guys. The -3 doesn't have any fasteners across the bottom of the cowl, so no problem there.

Tony

[mike newall]

If you are using countersunk screws consider this.

We refurbished a Christen Eagle before the RV project and the cowls were shot - lots of rebuild needed due to the screws damaging the fiberglass. When we re drilled the holes, we countersunk them and epoxied Tinnerman washers in the hole and glassed over with deck cloth. When set, just touch with a countersink to clear the cloth and you end up with a stainless receptacle for the screw that distributes the load into the cowl - will last for years and didn't take long to do.