Fold the hinge and dip the hinge line into heated petroleum jelly, then work
the hinge a few times to lubricate it...
If these are NYLON hinges I would not use CA to glue them. Use 30 min epoxy
after roughing the tabs and drilling anchor holes if none are present.
Also, ALWAYS(!!) pin nylon hinges after installation....
"Also, ALWAYS(!!) pin nylon hinges after installation" -
Unable to agree 100% in this instance. In most models, the use of pins or
the thick round toothpicks seen many times is not required = IF one has
carefully spread epoxy throughout the hinge slot and covered the Nylon hinge
tab on both sides with epoxy so that epoxy fills the holes "after roughing
the tabs and drilling anchor holes if none are present". ( pins maybe
desirable on models with high stress on the control surfaces, e.g warbirds
The epoxy will set through the hinges like an "I" beams and not weaken the
structure. Nylon hinges epoxied in this manner are not known to have pulled
out - only those where builder had pushed the glue into the slot and then
the hinge which simply pushed the glue into the wing with little remaining
to adhere to and through the hinge itself.
If repairs should be required at a later date, then a hot knife blade will
clean the old hinge and epoxy out with ease. A pin or similar may be
difficult to extract without causing damage to the surrounding wood which
must then be replaced with new wood.
Alan's Hobby, Model & RC Web Links
I also would suggest Gorilla or Elmers Pro Bond poly glue. A little goes a
long way as it expands when it cures. Coat the pins the same as for epoxy. I
usually check and remove the excess as it cures and expands. Never had one
pull out yet. Oh yes , if you dampen the area to be glued it speeds up the
Hinges made out of any material( fabric, plastic , CA, nylon, or
whatever) can be pinned. All this means is drilling a hole and putting
a toothpick or a pin in it. If the CA or epoxy has been applied
properly, this is probably unnecessary considering the control surface
is held on by more than one hinge. It's very unlikely they would all
fail at once. However, during very hard use, like my planes, hinges can
loosen up. With CA, you just add another drop or two. Epoxy is another
story and is sometimes difficult to repair.
I used to do this, and hated it.
It was a messy, finicky pain in the ...
I would always end up with petroleum jelly getting onto the flat
(thus compromising the epoxy bond), epoxy everywhere, and how do you
the epoxy gooped tab in the slot when its free to rotate as you hold
other piece ...
Also, if you had enough epoxy for a good bond, then some would squeeze
out, forming a shoulder that has to be removed later ....
(can you tell I hated hinging ?)
I eventually came up with a faster, cleaner, better way.
Cut slots as normal, perhaps a bit "thin" so you get a nice tight fit.
Roughen tabs as normal.
Slide dry hinges into place and align ...
BEFORE GLUING, drill hole for toothpick pin through balsa and hinge.
Cut pin to size and install dry with hinge in place (still no glue)
Check to make sure alignment is still perfect.
Drip a couple of drops of THIN CA onto the toothpick ...
When no more CA will wick into the pin/hole, blot excess w/ tissue
Flip surface over, and drip onto bottom of toothpick.
The CA would wick down alongside the toothpick, and then spread out
the slot. Because it was not applied near the front none would get into
When I first thought to try this I was worried about strength ... I
wasn't sure CA would be strong enough with nylon...
So I did some destructive testing :)
I know what you're thinking , but NO, I did NOT intentionaly crash
I made little trailing edges with some scrap wood ...
The first couple test pieces the wood would break before the hinge
... So I got some thicker harder balsa or light ply (I forget) and ran
test series number 2.
The wood was now stronger and did not break ... the hinge did NOT pull
out ... the metal pin holding the 2 halves of the hinge together would
bend and/or pull through the plastic.
In other words, the wood to hinge bond was stronger than the hinge
That was my standard method for many years until I found something even
better ... Robart Hinge points ...
MUCH NICER than flat hinges ... no slots to make ...
Just drill a (Slightly Undersize) hole in each surface.
Put a couple drops Titebond wood glue in each hole.
Insert hinges. (if enough glue was used, some excess WILL squeeze out)
The Titebond doesn't really stick to the Robart plastic all that well,
the excess that squeezed out (and all over the hinge pin) will simply
flake off !!!
But ... But ... But ... If the glue don't stick ...
... WHATS HOLDING THE HINGE IN !?!?!?!?
The shape of the Robart Hinge Points ...
They have little saw-tooth ridges on them. The moisture in the Titebond
expands the wood fibers, and the wood and dried Titebond form
that lock in the Robart Hinge Points.
Destructive testing was again performed ... the bond was again stronger
than the hinge itself.
Heck, with a properly sized hole it can be tough to get the little
buggers out after alignment tests -- even though no glue was used yet.
As a final note,
Alan T. suggested not pinning in case repairs are needed ...
Has this ever been an issue for anyone reading ?
I have had to repair/replace a CA type hinge that wore out,
(to be fair the alignment was messed up and thus higher stress)
but I have NEVER had to replace pin type hinges.
And if one surface got messed up enough to require replacement,
I was able to cut it off the hinges and reuse the existing hinges.
I also did have hinges that were installed as well as I could (using
epoxy but no pins) pull out before. I got severe flutter on a
trainer/floater, and both ailerons pulled out ... luckily it had enough
dihedral to be able to land using rudder & elevator. That convinced
me to pin them from then on.
I'm certainly not suggesting that anyone NOT pin their hinges , cause
it's a 'good thing '.....but I have never had a failure and I never
pin them. I've been using the CA hinges for close to 20 years. The
first ones I ever bought were called Radio South Pro hinges as I
recall. I now buy an 8x10 sheet and cut out what I need.
My opinion is that many people put too much glue on the hinges and
make them brittle at the hinge line. Just my opinion.