Spar gluing

[Lou Parker]

Anyone know of any downfalls to using liquid nails to glue spars together?
And yes, I expect the usual ignorant smart asses, who really don't have an answer.
Lou

[John Kimmel]

Death.

Lou Parker wrote:
> Anyone know of any downfalls to using liquid nails to glue spars together?
> And yes, I expect the usual ignorant smart asses, who really don't have an answer.
> Lou

[Ron Natalie]

"Lou Parker" > wrote in message om...
> Anyone know of any downfalls to using liquid nails to glue spars together?

Liquid Nails isn't much on shear strength and it's pretty thick when applied.

[Rich S.]

"Lou Parker" > wrote in message
om...
> Anyone know of any downfalls to using liquid nails to glue spars together?
> And yes, I expect the usual ignorant smart asses, who really don't have an
answer.
> Lou

I built a bird feeder with liquid nails. It lasted six months and then fell
apart.

Rich "ISA" S.

[Del Rawlins]

On 19 Nov 2003 09:01 AM, Lou Parker posted the following:
> Anyone know of any downfalls to using liquid nails to glue spars

Interesting choice of words.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[MJC]

Don't do it. Liquid Nail (brand name) is not strong enough in the ways that
count for spars.
There's a reason why 30 minute (or longer) epoxy has been used for this
purpose for so long.
I'd give you a smart ass answer too but I can't think of one at the moment.

MJC

"Lou Parker" > wrote in message
om...
> Anyone know of any downfalls to using liquid nails to glue spars together?
> And yes, I expect the usual ignorant smart asses, who really don't have an
answer.
> Lou

[O-ring Seals]

On Wed, 19 Nov 2003 15:57:07 -0600, "MJC" > wrote:

>Don't do it. Liquid Nail (brand name) is not strong enough in the ways that
>count for spars.
>There's a reason why 30 minute (or longer) epoxy has been used for this
>purpose for so long.
>I'd give you a smart ass answer too but I can't think of one at the moment.
>
>MJC
>
>
MJC,

A question like that does not deserve even a smart ass answer.

O-ring

[Dan Thomas]

"Rich S." > wrote in message >...
> "Lou Parker" > wrote in message
> om...
> > Anyone know of any downfalls...

Apt use of the term.

Dan

[[email protected]]

On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:

:Anyone know of any downfalls to using liquid nails to glue spars together?
:And yes, I expect the usual ignorant smart asses, who really don't have an answer.
: Lou

Unless you're talking about tacking things together with liquid nails
while the real glue cures, the glue joint will be very, very weak in
comparison with the underlying material, and subject to creep. So you
will have to size up the material significantly. Probably to the
point where no amount of power will get you off the ground. Or,
accept a safety factor under 1. Better to use almost anything else,
even white glue from the drugstore.

Other problems -
Screaming on your way to the ground can irritate the throat
The crash may cause the surrounding brush to catch fire
A shameful waste of a perfectly good engine and instruments
Increased accident rates make EVERYONE's insurance rates go up

[Bob Kuykendall]

Earlier, (Lou Parker) wrote:

> Anyone know of any downfalls to using
> liquid nails to glue spars together?

Here's the data sheet for the most common formulation of Liquid Nails,
the one called Liquid Nails for Projects:

http://www.liquidnails.com/datasheets/ln601ds.pdf

It shows a best shear strength, achieved after 4 days of cure time, of
"Exceeds 400 psi." I suspect that's like 99-cent deer nuts being under
a buck. And there's no data about how reliably you can count on that
figure.

In comparison, most aircraft-use epoxies will give you a shear
strength of better than 2000 psi, of which you can consistenly enough
count on 1000 psi. Check out the epoxy strength curves on this Sequoia
Aircraft page:

http://seqair.com/skunkworks/Glues/Notes/Notes.html

That said, I've always got a tub or tube of Liquid Nails for Projects
up at the shop. The last time I used a lot of it was to glue on a
canopy for my HP-18. So far, it's held up better than the earlier two
glues that were used for that job.

Thanks, and best regards to all

Bob "never argue with the data sheet" K.

[- Barnyard BOb -]

>"Lou Parker" piped up:

>> Anyone know of any downfalls to using liquid nails to glue spars together?
>> And yes, I expect the usual ignorant smart asses, who really don't have an
>answer.
>> Lou
>
>I built a bird feeder with liquid nails. It lasted six months and then fell
>apart.
>
>Rich "ISA" S.
++++++++++++++++++++++++++++++++++++++++++++++++++ +++

I used only Liquid Nails and a smile.....
to hold 2 x 4 foot sheet styrofoam panels of
insulation to my raw concrete basement walls.
None of it rests on the floor for support.

No idea how long it will stay glued.......
it's only been up 20 years to date without
a single panel coming loose.


Barnyard BOb -- well known smart, smart ass.

[Stealth Pilot]

On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:

>Anyone know of any downfalls to using liquid nails to glue spars together?
>And yes, I expect the usual ignorant smart asses, who really don't have an answer.
> Lou

maybe I'll be the only one to give you a serious answer.

aircraft wood glues have a number of requirements on them that the
usual off the shelf glues cant satisfy.

wings out in the sun get quite hot and they may be in the air under
load in this condition. this means that thermo softening glues, such
as liquid nails, pva etc cant be used because they WILL fail under
load when hot.

wood will expand and shrink slightly with different moisture
conditions, sometimes one side of the joint can be moist and one side
relatively dry. this may seem insignificant but in actual fact is one
situation which anything but the best of joints will be destroyed by
over time. the differential wood expansion sets up large sheer
stresses across the glue joint. if you have a weak glue you may just
end up with only half of it remaining and half of it showing cracking
from the stresses. for this reason varnishing to water proof the wood
is essential for any glue, as is making the glue joint with wood that
has the same moisture content.

aeroplanes (wonderful word that) last quite a while so it is essential
that the glue last longer than the life of the aircraft. Acid
catalysed phenolics (like Selleys 308 in australia ) use formic acid
applied to one side of the joint to set off the resin mix applied to
the other side of the joint (it sets off when they are put together)
this acid catalyst has been found to continue working as an acid after
the cure and has led to wood failures beside the glue joint. people
have died in structural breakups of aircraft because of it.

currently there are two basic wood glues that have stood the test of
time in aircraft structures. they are Resorcinol Formaldehyde which
was developed all the way back in the 1930's and wood compatible epoxy
resin. (not all epoxys are suitable)

It doesnt cost anything more to use a wood glue that will last the
distance so I would implore you to use a proper, tested by time, wood
glue.

Both of the glues I mentioned as suitable have little factors in their
use which need to be understood. I'll leave it to you to research
those.

Btw I asked Australia's CSIRO about modern glue research a few years
ago for my work with the SAAA. "yeah we're doing lots of it but under
contract so I cant show you the results of the tests. I will tell you
that Queensland Hoop Pine is exceptionally easy to glue (it's not much
different from spruce) and in all of our tests to destruction
Resorcinol Formaldehyde glues have outlasted the wood."

I should mention casein glue in passing. it works but is eaten by
bacteria if it ever gets moist an is unreliable over the life of the
vaerage aircraft.

Hope that helps.
simple as it is it is critical that you get glueing right.
Stealth Pilot

[Ron Natalie]

"Stealth Pilot" > wrote in message ...
> On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:
>
> >Anyone know of any downfalls to using liquid nails to glue spars together?
> >And yes, I expect the usual ignorant smart asses, who really don't have an answer.
> > Lou
>
> maybe I'll be the only one to give you a serious answer.
>
I already pointed out that it doesn't have much sheer strength. Old liquid nails
joints also are real brittle. It only takes a few sharp blows to break the bond.
I've demolished a lot of stuff in my house that was put together with it.

[Lou Parker]

Stealth Pilot > wrote in message >...
> On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:
>
> >Anyone know of any downfalls to using liquid nails to glue spars together?
> >And yes, I expect the usual ignorant smart asses, who really don't have an answer.
> > Lou
>
> maybe I'll be the only one to give you a serious answer.
>
> aircraft wood glues have a number of requirements on them that the
> usual off the shelf glues cant satisfy.
>
> wings out in the sun get quite hot and they may be in the air under
> load in this condition. this means that thermo softening glues, such
> as liquid nails, pva etc cant be used because they WILL fail under
> load when hot.
>
> wood will expand and shrink slightly with different moisture
> conditions, sometimes one side of the joint can be moist and one side
> relatively dry. this may seem insignificant but in actual fact is one
> situation which anything but the best of joints will be destroyed by
> over time. the differential wood expansion sets up large sheer
> stresses across the glue joint. if you have a weak glue you may just
> end up with only half of it remaining and half of it showing cracking
> from the stresses. for this reason varnishing to water proof the wood
> is essential for any glue, as is making the glue joint with wood that
> has the same moisture content.
>
> aeroplanes (wonderful word that) last quite a while so it is essential
> that the glue last longer than the life of the aircraft. Acid
> catalysed phenolics (like Selleys 308 in australia ) use formic acid
> applied to one side of the joint to set off the resin mix applied to
> the other side of the joint (it sets off when they are put together)
> this acid catalyst has been found to continue working as an acid after
> the cure and has led to wood failures beside the glue joint. people
> have died in structural breakups of aircraft because of it.
>
> currently there are two basic wood glues that have stood the test of
> time in aircraft structures. they are Resorcinol Formaldehyde which
> was developed all the way back in the 1930's and wood compatible epoxy
> resin. (not all epoxys are suitable)
>
> It doesnt cost anything more to use a wood glue that will last the
> distance so I would implore you to use a proper, tested by time, wood
> glue.
>
> Both of the glues I mentioned as suitable have little factors in their
> use which need to be understood. I'll leave it to you to research
> those.
>
> Btw I asked Australia's CSIRO about modern glue research a few years
> ago for my work with the SAAA. "yeah we're doing lots of it but under
> contract so I cant show you the results of the tests. I will tell you
> that Queensland Hoop Pine is exceptionally easy to glue (it's not much
> different from spruce) and in all of our tests to destruction
> Resorcinol Formaldehyde glues have outlasted the wood."
>
> I should mention casein glue in passing. it works but is eaten by
> bacteria if it ever gets moist an is unreliable over the life of the
> vaerage aircraft.
>
> Hope that helps.
> simple as it is it is critical that you get glueing right.
> Stealth Pilot



Thank you. It looks like we have a couple of winners. Just for your
piece of mind, I have used nothing but T-88 on my project, but once in
a while a question like this comes my way.
Thanks
Lou

[Bob Kuykendall]

Earlier, Stealth Pilot > wrote:

> Acid catalysed phenolics (like Selleys
> 308 in australia ) use formic acid ...
> ...this acid catalyst has been found
> to continue working as an acid after
> the cure and has led to wood failures
> beside the glue joint. people have
> died in structural breakups of
> aircraft because of it.

The issue of acid-catalyzed urea-formaldehyde glues in Australia is
explored somewhat in the article I cited earlier in this thread. Not
being a wood enthusiast I don't really care one way or the other, but
I think that folks who do care should know that there is more than a
single side to this particular story.

Bob K.
http://www.hpaircraft.com/hp-24

[Gig Giacona]

"Bob Kuykendall" > wrote

> ...like 99-cent deer nuts being under
>a buck....


You owe me a keyboard Bob.

[Fred the Red Shirt]

- Barnyard BOb - > wrote in message >..
>
> I used only Liquid Nails and a smile.....
> to hold 2 x 4 foot sheet styrofoam panels of
> insulation to my raw concrete basement walls.
> None of it rests on the floor for support.
>
> No idea how long it will stay glued.......
> it's only been up 20 years to date without
> a single panel coming loose.
>

That doesn't really surprise me. The solvent in
the liquid nails probably melted the styrofoam a
bit creating a good bond. Those panels are not
subjected to any significant stresses, certainly
no aerodynamic stresses nor do I imagine, does
your basement get as warm as an aircraft on a
hot day in teh sun. Probably not much exposure
to moisture or cold temperatures either.

Besides, those panels didn't weigh dick in the
first place.

For spars *I* would only use epoxy or a urethane glue
like Gorilla glue. Resourcinol glue, used in boat
building might be good too.

I suggest that you only rely on something that
a siginifacnt number of other folks have used
and survived. Learn from other people's mistakes.

--

FF

[Fred the Red Shirt]

Stealth Pilot > wrote in message >...
> On 19 Nov 2003 10:01:51 -0800, (Lou Parker) wrote:

Got any info on urethane glues like Gorilla glue?

They're supposed to be good for outdoor wood projects.

Also a note on varnishing:

All film finishes for wood, paint, varnish, laquer, shellac (I think
that is all) will allow water vapor diffusion so that changes in
humidity will still cause the wood to expand and contract. What
these finishes do for the structure is to SLOW the rate of
diffusion so that any moisture gradient within the wood is
minimized. This in turn minimizes warping, but not the
overall dimensional change.

The expansion and contraction of wood with moisture content is
anisotropic. Wood expands and contracts the most along the
grain boundaries. This will be accross the fact of most boards
that you get by sawing the log through and through, that is
in the direction that was tangent to the circumfrence of the
tree. Wood expands and contracts less accross the grain, that
is in the direction that was radial in the tree trunk. It
hardly expands and contracts at all in length.

I have read that Doug Fir is uniquely stable among woods in
that it expands and contracts equally in both the radial and
circumferential directions and so it is the only wood commonly
sold as dimensional lumber while still green (others will usually
be kiln dried to 12 % MC) However, I have seen Doug Fir boards
cup and uncup with variations in humidity, indicating to me
that this is not true.

--

FF

[Bob Kuykendall]

Earlier, "Gig Giacona" > wrote:

> You owe me a keyboard Bob.

I'm sure glad somebody got that one.

Here's the full riddle:

What's the difference between beer nuts and deer nuts?

Beer nuts are $1.39, but deer nuts are under a buck.

Thanks, and best regards to all

Bob K.

[- Barnyard BOb -]

(Fred the Red Shirt) wrote:

>I suggest that you only rely on something that
>a siginifacnt number of other folks have used
>and survived. Learn from other people's mistakes.
+++++++++++++++++++++++++++++++++

You've got my vote, Fred.

However, there is a core of wannabees hell bent on
re-inventing the wheel in some ridiculous manner, at
least with their keyboards most every day - all under the
guise of *EXPERIMENTING*. Anyone that poo-poos
their nutty notions without great care are labeled as
anti-experimenters or worse and are subject to very
hostile and denigrating attacks. You know the drill...

<<<<< KILL THE MESSENGER >>>>>

Barnyard BOb - over 50 years of successful flight

[Morgans]

"Fred the Red Shirt" > wrote
>
> I have read that Doug Fir is uniquely stable among woods in
> that it expands and contracts equally in both the radial and
> circumferential directions and so it is the only wood commonly
> sold as dimensional lumber while still green (others will usually
> be kiln dried to 12 % MC) However, I have seen Doug Fir boards
> cup and uncup with variations in humidity, indicating to me
> that this is not true.
>
> --
>
> FF

Indeed, it is not true.

See http://www.woodweb.com/Resources/wood_eng_handbook/Ch01.pdf for all you
ever wanted to know about wood, and more.
--
Jim in NC

[Big John]

BOb

You got to remember that your panels are basically supported by the
glue in a shear situation. Even kids white glue will do pretty good in
shear.

When you put things in peal you get a different result so don't lead
the neophytes astray.

Bob, you got to remember that some of the young'uns don't have any
experience with the hot hide glues like they used to build the
'Jennys' <G>

Big John


On Thu, 20 Nov 2003 00:21:18 -0600, - Barnyard BOb - >
wrote:

>
>
>>"Lou Parker" piped up:
>
>>> Anyone know of any downfalls to using liquid nails to glue spars together?
>>> And yes, I expect the usual ignorant smart asses, who really don't have an
>>answer.
>>> Lou
>>
>>I built a bird feeder with liquid nails. It lasted six months and then fell
>>apart.
>>
>>Rich "ISA" S.
>++++++++++++++++++++++++++++++++++++++++++++++++++ +++
>
>I used only Liquid Nails and a smile.....
>to hold 2 x 4 foot sheet styrofoam panels of
>insulation to my raw concrete basement walls.
>None of it rests on the floor for support.
>
>No idea how long it will stay glued.......
>it's only been up 20 years to date without
>a single panel coming loose.
>
>
>Barnyard BOb -- well known smart, smart ass.

[Corky Scott]

On Thu, 20 Nov 2003 23:23:23 -0600, - Barnyard BOb - >
wrote:

>
>(Fred the Red Shirt) wrote:
>
>>I suggest that you only rely on something that
>>a siginifacnt number of other folks have used
>>and survived. Learn from other people's mistakes.
>+++++++++++++++++++++++++++++++++
>
>You've got my vote, Fred.
>
>However, there is a core of wannabees hell bent on
>re-inventing the wheel in some ridiculous manner, at
>least with their keyboards most every day - all under the
>guise of *EXPERIMENTING*. Anyone that poo-poos
>their nutty notions without great care are labeled as
>anti-experimenters or worse and are subject to very
>hostile and denigrating attacks. You know the drill...
>
> <<<<< KILL THE MESSENGER >>>>>
>
>Barnyard BOb - over 50 years of successful flight

Was this necessary?

Corky Scott

[- Barnyard BOb -]

>BOb
>
>You got to remember that your panels are basically supported by the
>glue in a shear situation. Even kids white glue will do pretty good in
>shear.
>
>When you put things in peal you get a different result so don't lead
>the neophytes astray.
>
>Bob, you got to remember that some of the young'uns don't have any
>experience with the hot hide glues like they used to build the
>'Jennys' <G>
>
>Big John
++++++++++++++++++++++++++++++++++++++

Heavens to Betsy, alpha dawg:

When I tell neophytes to stay the hell away from
auto conversions in the strongest terms known
to man and beast....who takes me seriously?
The neophytes?
HELL NO - I get roasted, toasted, sliced and diced.

When I post lite hearted tongue in cheek horse****,
what do I get? Yep... your post.

Can't win. <g>

P.S.
Outta' time. Gotta' go now....
and test fly my 300 mph Crazy Glue & Styrofoam special.
I'm having issues with the GM locomotive 2 stroke diesel.

P.P.S.
eBay Brooklyn Bridge reserve still not met


Barnyard BOb -- Union Pacific RR - tired and retired

[AL]

It was BOb. Why be necessary?


Al Mills

[Big John]

BOb

Guess 'hot glue' was really before your time? (tongue in cheek) <G>

I expected a dissertation on it and its properties and uses on
aircraft.

And here's an Irish toast to thee.

Always remember to forget
the friends that proved untrue.
But never forget to remember
those that have stuck by you...


Always remember to forget
The troubles that passed away.
But never forget to remember
the BLESSINGS that come each day...


May the Lord keep you in His hand
and never close His fist too tight...


HERE'S TO A HAPPY & SAFE HOLIDAY SEASON!
STARTING WITH THANKSGIVING

Big John



On Fri, 21 Nov 2003 10:03:54 -0600, - Barnyard BOb - >
wrote:

>
>>BOb
>>
>>You got to remember that your panels are basically supported by the
>>glue in a shear situation. Even kids white glue will do pretty good in
>>shear.
>>
>>When you put things in peal you get a different result so don't lead
>>the neophytes astray.
>>
>>Bob, you got to remember that some of the young'uns don't have any
>>experience with the hot hide glues like they used to build the
>>'Jennys' <G>
>>
>>Big John
>++++++++++++++++++++++++++++++++++++++
>
>Heavens to Betsy, alpha dawg:
>
>When I tell neophytes to stay the hell away from
>auto conversions in the strongest terms known
>to man and beast....who takes me seriously?
>The neophytes?
>HELL NO - I get roasted, toasted, sliced and diced.
>
>When I post lite hearted tongue in cheek horse****,
>what do I get? Yep... your post.
>
>Can't win. <g>
>
>P.S.
>Outta' time. Gotta' go now....
>and test fly my 300 mph Crazy Glue & Styrofoam special.
>I'm having issues with the GM locomotive 2 stroke diesel.
>
>P.P.S.
>eBay Brooklyn Bridge reserve still not met
>
>
>Barnyard BOb -- Union Pacific RR - tired and retired
>

[Corky Scott]

On Fri, 21 Nov 2003 11:25:03 -0600, "AL" > wrote:

>It was BOb. Why be necessary?
>
>
>Al Mills

He posts stuff like that and then wonders why people get irritated
over things he posts. Actually complains about it here in this very
group.

Corky Scott