How about the long term strength after several years of going thru the 4
seasons(if you have them). I bought a partially built large kit and
some of the joints gave away while handling it. I couldnt see
any dried glue on the joints but it was glued. I would estimate at least
10 years old.
The Natural Philos>
The one difference I see with the CA type glues, (aside from the health
issues) is the thin verity seems to give a brittle glue joint when used in
small butt type joints. Such as thin ribs and sheeting or formers and fuse
sides. There is almost no glue at the joint. IMO, thin CA soaks in to much and
the joint becomes susceptible to vibration and torsional failures. I build with
SIG Bond (wood glue) and use CA at times, usually to tack down a section. The
trouble with thin CA is most builders are not critical about their building and
the joints they are about to glue, they just simply hit it with glue. With
"fussy" ends to the wood or joints that are not a nice 90* butt joint, but
sanded at an angle, many times it`s not the glue used, it`s the joint. The wood
needs to also touch completly throughout the joint, not just a "section" of it.
Preparation guys, preparation. Another factor is the density of the wood at the
joint and the type of wood. I have never had much luck with thin CA and a
plywood firewall, have you? Do a little home experiment, take different types
of wood (and density`s) and glue up a few different joints with glues you have
in your shop. Also do some sloppy workmanship and see what seems to break
easier. Load on the glue and see if it makes a difference or not. I would be
willing to bet the trouble experienced lies in wood types and workmanship more
then the glue used itself.
My Model Aircraft Home Page
My oldest still active model is a Wild Thing 40, built 100% with CA in early
1992 -- It's survived two mid-airs, numerous 'arrivals' (verses landings),
and is still going strong -- and I might add with the original engine; an
Enya .46 4-c. Oh yes, it also was the first kit with CA-type hinges -- still
intact as well. Some covering got brittle and was replaced, but no
structural defects discovered.
Cheers -- \__________Lyman Slack_________/
\____Flying Gators R/C______/
\__Gainesville FL _________/
Visit my Web Site at:
My point exactly. If you can't make a good joint, you can't expect any glue
to work properly. Ine thing about CA, if it fills the gap it is stronger
than just about anything else. Wood glues (the yellow variety) are very
brittle and get worse with age if the joint isn't tight as well.
jim breeyear wrote in
Unfortunately, the mortality rate of my airplanes is not high enough for me
to have a lot of 10+ year survivors. Still, I have a few pieces from back
then, including a wing that dates back to Feb '88 and is still going
strong. It was built exclusively with CA. The covering is getting kind of
shaggy . . . (Black Baron film). And I think I still have 1 or 2 planes
from 1991, including a glider wing that a flew a few weeks ago.
We don't actually have seasons where I live, though - don't have any data
on whether extreme cold/dry cycles would make things worse.
Now, I've had problems with doped tissue - after about 10 years, it seems
to get very, very brittle. And I got to handle half of a 50-year-old old-
timer, and the wood itself had dried out so badly that it was completely
email@example.com (Aileron37) wrote in
Yeah. I use med/thick CA for most things anymore. Thin for hinges, of
course, or for repairing cracks or hardening TEs, but that's about it.
Also, I find that I use less glue with the medium because I have so much
better control of where it's going - the thin stuff seems to wick away so
quickly that most of it doesn't go where I want it.
I build with SIG Bond (wood glue)
Scary thought! If you kept pouring glue into the joint, I guess . . .
maybe . . . yech
Agree. Good workmanship with mediocre glue will beat mediocre
workmanship with good glue any day.
aileron37 wrote > I have never had much luck with thin CA and a plywood
Mark Miller wrote >Scary thought! If you kept pouring glue into the joint, I
guess . . .
Just for the record, I have never used CA for a firewall. My point was, I have
seen more then a few try it, even on larger aircraft. Makes you think.
My Model Aircraft Home Page
I have raced several warbirds with YS 91 engines (running 50% nitro) with
the firewalls, and everything else, glued with CA. Like I said previously,
if the joint is properly made, just about any glue will work. ALL of them
are stronger than the wood.
Cringe away. I've used CA on a giant Stinger, two 1/4 scale Dr.1's, and
everything else I've ever flown. Never had a structural failure.
What's REALLY scary is the guys using 5 minute epoxy on firewalls.
"There's a Hun in the sun!"
And you've likely used some extra bracing like tri-stock or the firewall was
interlocked with the fuse. Which I believe is proper with any type of
adhesive. I wouldn't trust a firewall with only a simple butt joint with
any type of glue. The joint design is very important.
You are quite correct. Either the plans called for tri stock or I added it. I
will also use 1/8" dowel through the fuselage sides into the firewall edge.
Sometimes I will make a rabbet joint between the fuselage sides and firewall.
ANY glued joint must also be mechanically sound. Trusting the glue alone to
hold a joint is asking for a failure. Look at how quality furniture and
musical instruments are put together.
However, in the case of CA, the wicking properties help make a sound mechanical
joint as the glue is pulled into the grain.
"There's a Hun in the sun!"
There's one thing bothering me about this praise of CA adhesives.
I remember someone trying to promote a "de-activator" to de-bond accidental
CA joints e.g. fingers stuck together.
The sales rep bonded a friend's finger and thumb together - they were quite
well stuck. Before the deactivator could be applied my friend simply gave a
quick shock to the joint by knocking a ball point pen between his finger and
thumb and the two sprang apart - much to the surprise of the "expert".
After that demonstration I have only used CA for quick, temporary field
repairs so as to be able to keep flying, and only then for lightly stressed
Gluing your fingers together is a hit or miss proposition. I have had times
where the CA would not bond my skin and other times I had to soak in
debonder for minutes (not good gor you!). Also, most CAs will peel off your
skin in an hour or two as the natura oils cause it to lose bond.