Model Forum / General / Models / October 2007

yeah I would definately use regular wood glue, liek titebond or
something but, I read that the CA glues have a 12-second set time as
opposed to the 30-minute set time with the wood glues, which means I'd
need to use clamps most likely, correct?

Yes, use the GEL variety, the thicker, slower setting stuff.  I also
use white glue, which is cheaper. I use the white glue for assemblies
that are going to be pinned down for awhile, CA when I need the
quicker set.  I also use the CA for areas that will be finished,
because the white glue is harder to sand and paint.

Also, I have built these as shelf scale models, covering the metal
covered areas with sheet styrene. I use CA for gluing the styrene to
balsa.

If you're nostalgic and/or have a peverse amount of compulsive masochism,
you could use traditional (e.g. 50
+ years ago) acetate  model cements  such as Ambroid, or testors.  >However,
they are likely to be hard to find because they have been abused in the past
.. the notorious "Glue sniffing"  that provided a cheap but ultimately
deadly  high.
 As an  old-time balsa wood flying model builder and a present day, wooden
ship model builder, I can't imagine going back to the glues of last century
when when infinitely superior products such products as CA glues are
available  .. you might as well go back a few centuries and use hide glue or
fish glue as use Testor's.    CA from several manufactureres are available
in four grades, from very thin, medium thin,  thick (gap filling) to
gel(really thick. ).  The thicker the formula the longer the setting time.
Very thin sets in 15-30 second.  Gel in 10-15 minutes.  All of them can be
accelerated by using an accelerator such a "Zip Kicker"  The thin stuff,
even without an accelerator gets hot.  For balsa, especially soft balsa, the
thin stuff socks into the wood  an reinforces wit so that the material
around the joint is much stronger than the raw wood.  .The closer
wood-to-wood  fit, the stronger the joint.  The main reason for using the
thicker stuff is not for a stronger joint, but to provide various degrees of
gap filling.   CA glues are generally employed without clamping.  CA glues
are used by some modelers to provide a temporary "clamp" for use in
conjunction with wood glues these CA glues are available at any good hobby
shop that sells flying models or ship models
 Now as for using a modern wood glue, such as tight bond. These also come
with different setting times.here, the slower setting (e.g. tight-bond III)
. versions are stronger.  Setting time is measured in hours (24-48)   .The
joint is generally stronger than the base wood.  All are available at a good
woodworking supplier. There is no reason to deal with the long setting and
clamping times of wood glues in a flying model,.  In the wooden ship model
community, there is an ongoing discussion over the use of Wood glues (tight
bond), versus CA glues.  The question revolves around whether or not CA will
last 100  years or more.  We know that epoxy joints  and epoxy gets weaker
and brittle with age, the verdict isn't in for CA.  Since balsa models are
usually flying models, and since most don't survive the first attempted
flight, the issue of lasting 100 years is moot.
BTW-- violin makers use traditional hide or fish glue precisely because the
are known to last 100
+years, an also because it is possible to safely undo an old glue joint.

Boris

gap filling

)_

About the time it takes to set, I see.  You made several mistakes.  Once you
rectify those errors, you'll find that CA's are THE adhesive s of chi=oice
for wood nmodels,specially, balsa models.

1.  I mentioned the fact that the closer the wood-to-wood fit, the better
the joint.  Use really sharp tools and get a very good,accurate fit before
you apply the cement.

2. parts should be held together by pins to the board and/or other kinds of
clamps.  Never use your fingers as a clamp. with CA. What were your fingers
doing any where near the joint.

3.You used far, far, far too  much of the stuff,  so it slopped all aver the
place and on to your fingers.  The tip, rspecially fo thin CA is much too
gross.  You can buy applicator tips that are like a fine hypodermic needle,
so you squeeze out only one tiny drop at a time ... just at the joint and
bowheres else.  I sometimes put a drop on a toothpicjk nd touch that to the
joint.
it wicks in an without any slop.  I also use dental pick, which have the
dvantage that you can clean them.   There are many other rypes of
applicators you can use.

Which is great, because it really strenghtens the joint.
but it went right through the balsa to my fingers.

Goes to show, yet again why theGullows kits were the worst ones on the
market.  They used only the cheapest, softest balsa.  Better balsa does not
wick so violently.

Good hobby shops also sell de-bond (bond disolver) which is far  more
effective than nail polish remover.  Acetone also works better.  Always have
some debonder around, because we all make mistakes.. and even after years of
using, also occasionally glue fingers together.

A poor substitute for tight-bond
or plain Elmer's White Glue.
An even more inferior product compared to tight bond.

Since you're new to CA, note that it is the adhesive of choice when you cut
your finger with the sharp scalpel.  Jut push the joint together to a good
approximation, dab the excess blood off and put on a drop of CA.  Stings,
but works perfectly.Can often (and is used by doctors to avoid stitches.  Of
course you can use the "medical" CA at$5.00 /cut,  but hobby CA is just as
sterile an works as well.    Let's see you do that with Elmer's

Boris

That is why you need to use the gel form of CA on balsa.  It dries
slower than the regular CA, but far quicker than white glue.