Plywood bonding to Aluminum fuselage structure ??

I wonder if you guys can answer a question about aircraft adhesive and
techinques.

I am considering the option of gluing aircraft plywood to a aluminum
tube fuselage structure. After reading about properties of adhesives
to perhaps accomplish this effort I stumbled upon T88. If I used such
an adhesive to bond plywood to aluminum can it ever be removed if I
wanted to re-panel the fuselage with new plywood a few years down the
road? Conversely, are there other ways to panel a aluminum tube
fuselage with plywood?

Candice

Hi guys,
thanks all for the responses. Doing further research I have an idea
of bolting thin furring strips to the aluminum fuselage structure.
Countersink the heads, washers, lock nuts. My idea is to soak these
and bolt them gently to the fuselage with so they can cure to the
correct curve. Then remove the furring and fully varnish it.
Re-attach via lock nuts. Then glue the fuselage siding onto the
underlying furring.

The benefits are removable of the fuselage skins can be accomplished
by unbolting the underlying furring strips from the aluminum. The
other benefit is I avoid a direct glue joint between aluminum and wood.


Comments ???????????

Candice

Richard Riley wrote:
On 28 Nov 2006 16:37:33 -0800, "Candice"
wrote:

I wonder if you guys can answer a question about aircraft adhesive and
techinques.

I am considering the option of gluing aircraft plywood to a aluminum
tube fuselage structure. After reading about properties of adhesives
to perhaps accomplish this effort I stumbled upon T88. If I used such
an adhesive to bond plywood to aluminum can it ever be removed if I
wanted to re-panel the fuselage with new plywood a few years down the
road?


The epoxy would be fine for bonding the wood, but with time the bond
to unprepared aluminum weakens to zero strength. You're probably
going to end up with fastiners of some kind, like flush head screws,
tinnerman washers and nutplates.

Well, that would cure his repanelling problem. Wouldn't it? 8*0

You can remove epoxy with enough heat (usually 200+ degrees), a household
iron ought to do it, should soften the epoxy enough to pry the structure
apart.

This is why glass airplane wings at airshows have blankets over them when
parked in hot places on hot sunny days. :-)

The question of "why" still remains.


LM


"Candice" wrote in message
ups.com...
I wonder if you guys can answer a question about aircraft adhesive and
techinques.

I am considering the option of gluing aircraft plywood to a aluminum
tube fuselage structure. After reading about properties of adhesives
to perhaps accomplish this effort I stumbled upon T88. If I used such
an adhesive to bond plywood to aluminum can it ever be removed if I
wanted to re-panel the fuselage with new plywood a few years down the
road? Conversely, are there other ways to panel a aluminum tube
fuselage with plywood?

Candice

Candice,
Is there a reason you are using plywood? BD-4's are being built every
day with aluminum bonded to the outside of aluminum structure with
Proseal adhesives. WWW.bd-4.org will get you into their site. The
latest is the bonding of aluminum sheet to ribs as a finished surface
with only rivits on the trailing edge. When they want a covering to be
removeable it is fastened with an bolts and nuts directly to the angle
structure. If you are using tubing and penetrating it for bolts I
would be concerned about weakening the structure by the penetration of
the bolts. the tightening would also distort the tubes. Depends on
your structure. Jim Bede did a paper on the strength of fastener types
that is also available on the website. good luck with it and have fun.


Dean B.

Hi guys,
Thanks for all the comments. I should of explained the plywood
angle first off. I'm just trying to engineer a viable option of
building a full scale Siemens Schukert D4 which had a plywood fuselage.
The plywood in this case would just be for skinning and not for
strength, although I would think it would act as a stiffener on the
overall fuselage.

I'm doing this as an exercise because I was always interested in a
Albatros DII aircraft, again with the varnished plywood fuslage
skinning. The basic start with an aluminum tube structure is due to my
currently building a full scale Nieuport 17 by Airdrome Airplanes. I'm
very impressed with the overall strength of my N17 fuselage so it
seemed to be a good starting point for this evaluation.
I have a Rotec R2800 engine for that project. So..with the radial
engine that also makes a Siemens Schukert aircraft more attractive to
build since I already have an engine I can install from the Nieuport
should I go ahead.
I've heard that the Rheinbeck SIemens Schukert DIII had some
stability problems and wasn't flown much, although I'm not sure if they
even flew it at all. I've been building a model of the N17 in a
program designed to determine longitudinal stability of various
aircraft configurations. I will do a Siemens study in the near future,
but the plywood query was an exploratory question on my part since I
haven't worked on a wooden aircraft yet.

Thanks for all the help folks.

Candice Anne

"Candice" wrote in message
ups.com...
Hi guys,
Thanks for all the comments. I should of explained the plywood
angle first off. I'm just trying to engineer a viable option of
building a full scale Siemens Schukert D4 which had a plywood fuselage.
The plywood in this case would just be for skinning and not for
strength, although I would think it would act as a stiffener on the
overall fuselage.


fwiw, If you really want to hang plywood, I would think that the good old
fashioned plywood box with stringers would be less work and provide a more
"efficient" structure than aluminumn tubes with plywood attached for effect.
Glue it up and you are good to go.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Candice wrote:
I wonder if you guys can answer a question about aircraft adhesive and
techinques.

I am considering the option of gluing aircraft plywood to a aluminum
tube fuselage structure. After reading about properties of adhesives
to perhaps accomplish this effort I stumbled upon T88. If I used such
an adhesive to bond plywood to aluminum can it ever be removed if I
wanted to re-panel the fuselage with new plywood a few years down the
road? Conversely, are there other ways to panel a aluminum tube
fuselage with plywood?


ISTR that there are rivets with a large flange area for bonding plywood
to metal.

In small boat building there is a technique called "stitch and glue",
sort of like a monocoque plywood technique that could be useful
for building the fuselage.

--

FF

Fred,

I've been reading up on "Stitch & Glue" boatbuilding techniques.
What an interesting way to build a plywood structure. It just goes to
show that there really are no "dumb" questions to ask on this
forum...something novel will usually pop up. Thanks all, there is
still life in my research of this concept.

Candice
wrote:
Candice wrote:
I wonder if you guys can answer a question about aircraft adhesive and
techinques.

I am considering the option of gluing aircraft plywood to a aluminum
tube fuselage structure. After reading about properties of adhesives
to perhaps accomplish this effort I stumbled upon T88. If I used such
an adhesive to bond plywood to aluminum can it ever be removed if I
wanted to re-panel the fuselage with new plywood a few years down the
road? Conversely, are there other ways to panel a aluminum tube
fuselage with plywood?


ISTR that there are rivets with a large flange area for bonding plywood
to metal.

In small boat building there is a technique called "stitch and glue",
sort of like a monocoque plywood technique that could be useful
for building the fuselage.

--

FF