Author: "dimplemaster" <johnsiebold@...> Time: Tue Mar 2, 2004 6:11 am PST Link
Listers,
I will be using camlocs on the top cowl and maybe screws + nutplates on the lower
cowl-to-firewall attachment on a RV-7. The Cessna 172 that I own has metal
bushings in the front cowl bowls, and after 4,000 hours some are quite elongated by
the #8 screw through them. For those of you operating RVs, have you seen any
fiberglass wear in the through holes for screws, in particular, and camlocs (which do
have grommets), and what precautions did you build in to slow wear?
John Siebold
Cowlin' it up
Author: "wes9wm" <ragle@...> Time: Sun Mar 28, 2004 3:13 am PST Link
Hi John,
On the advice of a friend I also used camlocs on the upper cowl to
firewall attachment.
The main flange that accepts the base of the camlocs was prepared by
adding some thin aluminum strips (the width of the firewall flange)
between the firewall flange and the main flange. This allowed for
the addition of two or three layers (I used two, should have used
three) of fiber glass on the rear bottom of the top cowl half.
The glass strips were applied by wetting fiber glass tape, laying
them in place, laying a strip of aluminum (with the plastic coating
still on as a release agent) over the glass and clamping every 1.5 to
2 inches. Then, wipe off the resin which oozes out and allow resin
to cure.
The results was a beefed up, very smooth edge ready to be drilled and
counter sunk to accept the camlocs. You may be surprised how thin a
lay up of three layers is after squeezing out the excess resin.
If your like me, you have already drilled pilot holes in the cowl.
These holes will fill with resin and have to be cleaned out. If you
time it right (i.e. while the resin is still a little soft), it will
drill right out using your pilot holes as a guide. Be sure to keep
the resin from forming a bump where the pilot holes are and the clean
out will be easier.
As far as wear is concerned, ask me in about 10 years, no problem
yet ;-)
Good Luck,
Wes
--- In vansairforce@yahoogroups.com, "dimplemaster"
<johnsiebold@a...> wrote:
> Listers,
>
> I will be using camlocs on the top cowl, what precautions did you
build in to slow wear?
>
> John Siebold
> Cowlin' it up