Whoa Bud,
I didn't realise this response even existed when I rattled off my request for a
picture. Thanks heaps. I am going to digest it tomorrow, but I don't know how
you manage to get any work done with the amount of good gen you spread on the
list. Thank you once again Bud.
R
TR
On 19/09/2011, at 1:16 AM, Bud Yerly wrote:
> Tony,
> Yes it is possible, but take your time and make yet another flange to be able
to glue the all too important back bulkhead to the top. The short answer is the
baggage bay bulkhead sticks up only a little higher than the rear bulkhead
so it is worth it in my opinion to leave it alone and glass it in later...
>
> Now the reasons (read as the long and boring answer):
> I am getting less maneuverable with age so anything I can do to finish the
> lower
canoe and make my time in the aft fuselage more comfortable, I try to do.
It is no secret that I glass in my baggage bay floor prior to putting the top
on. Much fitting and adjusting is necessary adding a number of hours of
trimming,
measuring, and fitting. However all the tasks of installing trigears, and
fitting rear mounted batteries, flap drives, antenna planning, fuel pump
installation,
wiring, guiding rudder cables, fuel and brake lines, and the tedious
upside down work glassing of those baggage bay supports, becomes a snap. If
time is taken to properly prep the bulkhead and make a flange on the inside
of the top, it makes the task of crawling in the rear of the aircraft a final
inspection and hookup exercise rather than a construction exercise. This is
important,
and very welcome, when working alone where time is not a factor.
>
> A minor but important technical point is that the rear bulkhead has a foam
> core,
and I see many folks just cut the bulkhead to shape without considering the
edge of the bulkhead closeout. Technically the foam core, if cut and exposed,
needs to have the skins attached together by cutting out the foam core material
back 1/4 to half inch and filling with flox (done when the part is attached
to a flange forming an L bond), or leave the foam exposed and glass the front
and back (inner and outer) skins to each side of the top forming a TEE FLANGE.
Hard to use words to explain, but the strength of composites in bending and
buckling is the foam core to fiberglass bond. We know the foam is supposed
to be hollowed out at the exposed edge and filled or tapered to make a glass
to glass bond, but that is forgotten many times with the bulkhead and access
panels.
Note that in a perfect world, if we make a flange joint in the aircraft,
it is assumed to be a glass to glass bond. My technique is, if I expose the
foam core on the bulkhead, I glass both sides so I don't have to cut back the
foam and refill the void, or taper the end, to get the important glass to glass
bond. Refer to Chapter 23 or 33T on the techniques for a glass to glass bond.
>
> I spend a lot of time making bulkhead flanges and mass balance tower flanges
fit perfectly so I can put the top on in one shot, and I rely on my clecos and
screws to hold the tabs and flanges in position, all while keeping the top, tail
and stab perfectly aligned until the glue dries. The long pole in the tent
is that the top has to be final fitted (many times) and clecoed on as if it
were just glued in so all your flanges have the right shape and position...
>
> On a personal note, if you leave your bulkhead alone, sticking up, and spend
the time in the hole later, glassing the flange in position, it is actually
faster
and stronger to just leave your bulkhead loose and crawl in and glass it
in place on both sides after the top is on. All it takes to keep the bulkhead
where you want it for glassing, is to tack in a small block of foam or wood to
keep the bulkhead fixed and steady.
>
> In my opinion, if you you can't get into the hole, get a smallish helper, and
train him, it is faster and cheaper. The baggage bay bulkhead sticks up only
a little higher than the rear bulkhead and allows any wire tabs or attachments
to be fitted and clearanced also, so it is worth it in my opinion to leave it
alone and glass it in later...
>
> Regards,
> Bud
>
>
>
>
> ----- Original Message -----
> From: Tony Renshaw<mailto:tonyrenshaw268@gmail.com>
> To: europa-list@matronics.com<mailto:europa-list@matronics.com>
> Sent: Friday, September 16, 2011 3:03 AM
> Subject: Europa-List: Baggage Bay Upper Fuselage Attachment
>
>
>
> I'm trying to minimise the amount of redux and work needed to get a good job
gluing on this top. It aint for some time yet, but I'd like to bond in my
extended
baggage bay floor, and bulkhead. I can do this but then it sticks up in
the breeze acting as a nuisance. I've already layed up flanges on the arched
section
to mate with the roof, but what I'd really like to do is cut it off, and
bond it on later, once the top is on. It will be easy as I'll just redux it
in as one piece, and then I only need to do strapping patches both front and
back
of the cut areas. Does anyone see anything wrong with doing this?
> Reg
> Tony Renshaw
> Sydney Aussie
>
>
> http://www.matronics.com/Navigator?Europa-List<http://www.matronics.com/Navigator?Europa-List>
>
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>
>
>
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