Yes, but they are very expensive, since the S-Mart stores only sell them in
small tubes. I'm not sure if they sell a thin CA, usually they are in a gel
form. I've used them in a pinch, late at night when the hobby stores are
Where's the cheapest place to buy ca's, I
usually buy a load when I buy and I
think Balsa USA is as cheap as anybody I've
found. But I don't know everything so
that's why I'm asking.
Randy A. Hefner wrote:
When I was building to pay for my hobby, I bought the 8oz bottles and a
bunch of tips from Bob Smith. It worked out to a little over $1.00 an
You can store larger bottles in a refrigerator for a year or more.
The best place to store unopened bottles of CA is in the freezer compartment
of the frig.
I have some that is over a year old and it still works OK.
allow to get to room temp before opening
According to the manufacturers (when I was usimg POUNDS of the stuff a
week), it should be stored between 35-40 deg F. Looking at current
manufacturers web site, none recommend freezing. All recommend COOL storage
with none I could find recommending storage below 5 deg C.
I am not saying that your experience isn't valid, only what the
They MAY be the same and maybe not. There are a LOT of different formulas
made for different applications. Some plastic formulas don't work worth
crap on wood and vice versa.
I would stick with something known to work.
Just want to agree and add that I've used the stuff for field repairs
before and it's not as good. They tend to not penetrate the wood as well
and form a very brittle joint. You're also going to pay a lot more per
once for the stuff.
I had to do some research on "CA"s for an industrial (product assembly) use
and I do a lot of RC building. I am by no means an adhesive expert, but
here is some information.
"CA" (Ethyl Cyanoacrylate) is actually a "plastic" that starts as a liquid
and then polymerizes into a solid when it is in contact with a catalyst.
The environmental catalyst is water moisture that is present in or on the
surfaces to be bonded. That is why we see CA curing much more slowly when
the weather and the materials are very dry. "Kickers" are formulated with
additional chemical catalysts that speed the cure. Accelerating the cure
too much can adversly effect the properties of the joint.
CAs "don't like" an acid environment. CAs formulated for use with wood are
designed to better cope with the acidity found in wood material than is the
"X-mart" and other general use CAs. As a side note: When we use a dusting
of baking soda at the joint, the soda contains moisture AND creates an
alkaline environment and this speeds the cure.
The initial quality of the CA and the curing environment will determine the
Personally, I never use CA on any of the flotation areas of sea planes.
The purity of the liquid adhesive in the container (percentage of the active
chemicals versus general impurities and moisture) has a huge impact on the
bond strength. The better the purity, the higher the cost to formulate and
the higher the cost of the packaging container. There is no "cheap" way to
manufacture and package high purity CA. Generally speaking, adjusting for
"what the market will bear" retail pricing and pricing based upon "logo
reputation", the retail cost of the CA reflects the purity and the cost of
formulating for special viscosity properties.
Extremely high purity CAs formulated with very low inherit packaged moisture
(super dry CAs) may be great for critical product assembly, but have a
shorter life once the container is opened. I received some samples from
Germany that were as "pure" as possible and they were very difficult to use
for building models. They started to "kick-off" too quickly and required
special applicators in our humid environment.
Manufacturers who market to the model aircraft industry formulate for our
applications. When you see a big difference in the retail cost in CAs in
our market it usually means that the cheapest stuff has some of the quality
or characteristics compromised. Calculating the strength of the bond with
various levels of CA purity and "general use" formulations can be difficult.
If you compare the cost of purchasing high quality CA that has been
specifically engineered for our applications with the total cost of the
model materials, engine, and radio equipment - why compromise the structural
integrity of your model to save a little money.
CA is very strong in tension and very poor in shear. We do use CA in some
applications where the joint experiences shear forces. The higher the
quality of the CA, the better chance you have of the adhesive being able to
deal with a minor shear component of the joint stress.
When CA "cures" it forms a polymer joint between the two materials. If the
CA is "wicked away" from the joint, the amount of the polymer left may not
be sufficient to have the strength required at the joint. That is why balsa
joints where one of the members to be joined is end grain can be
significantly weaker than "face" grain joints. Capillary action in the
balsa can wick all of the CA away from the joint. The "medium" and "thick"
CAs are better suited for end grain joints than the "wicking" formulations.
However, there are times when the joint can be made even stronger by first
using "thin" CA to wick a little into the end grain and then quickly
applying thicker CA to the joint faces.
There is a caution about wicking CA into the end grain of small structural
members to "make them stronger". Unless specially formulated, CA doesn't
like "shock" stress at all and wicking it fully into a length of soft balsa
can reduce the elasticity of the balsa and cause a "brittle"failure. Also,
using "gap filling" CA to bridge spaces at poorly fitting component joints
can make the joint more susceptible to brittle failure.
I hate kits that are shipped with longeron or spar stock that is smaller
than the cut-outs in the formers or ribs. This defect couples the
difficulty of making good CA joints in end grain with the limitations of
"thick" CA joints. I always take the time to cut balsa shims to fill the
High quality, true "aircraft ply" with face laminations made from wood with
tight grain can present another problem with CA joints. This ply is
fabricated under a lot of clamping pressure and the face laminations can
have a "shine" from the compression. You will often see this with Birch
ply. It is a good idea to "rough up" the gluing surface with some 220
abrasive paper. This permits the penetration of the CA that is required.
Conversly, some "laminated wood products" that are shipped with kits have
face laminations that are so porous that thin CA will wick away from the
face joint. This is where you need to use "medium" or "thick CA" to get a
Finally, some notes on storage of CA. Moisture is the enemy. This moisture
can be a "as packaged" quality issue. But, it is often a major issue once
the container is opened. High quality UNOPENED containers of CA can be
stored in the freezer and then slowly thawed, unopened, until they reach
room temperature. Many manufactures say this is a no-no even with unopened
containers. Most manufacturers will tell you to NEVER put opened CA into
the refrigerator or freezer because of condensation of moisture in the
You must be very cautious of moisture condensation in the container when you
have kept the CA in any chilled environment. This even applies to having
the CA in an airconditioned house and moving it into a higher humidity
environment like a garage shop.
Once you have opened the container, use both the inner cap and the outer cap
on the container when ever you are not actually applying the CA to a series
If you are using a "kicker" - never store the kicker in the same area as the
CA. And, never spray the kicker toward the container on your bench.
I store opened bottles of CA in small "zipper closing" plastic bags into
which I have placed a small package of dessicant. I save all of the little
bags of dessican that come with electronic items and some food items.
Friends/neighbors know to save theirs for me. It is interesting to note
that without the dessicant in the bag, I have seen a "blush" of CA on the
inside of the bag even with both container caps in place. This means that
the caps don't seal perfectly once the inner cap is opened and CA vapor
escapes into the bag.
I hope some of this will be of use to you.
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.