News:



  • June 22, 2025, 06:35:49 AM

Login with username, password and session length

Author Topic: Smoking CA  (Read 1287 times)

Offline Dick Pacini

  • 25 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1649
Smoking CA
« on: June 05, 2011, 11:42:16 PM »
Why is it that CA will sometimes give off a whiff of smoke during application and other times it doesn't?
AMA 62221

Once, twice, three times a lady.  Four times and she does it for a living.  "You want me on that wall.  You need me on that wall."

Offline PJ Rowland

  • AUS - 29541 AMA - 809970
  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 2056
  • Melbourne - AUSTRALIA
Re: Smoking CA
« Reply #1 on: June 06, 2011, 12:42:23 AM »
Normally, superglue in the tube is made up of lots of little units (monomers), which, when the glue cures, link up to become long chains of those units (polymers).

In order to start the reaction off some water is normally needed.. damp things stick better/quicker than dry ones and the glue goes hard faster on a humid day.

Only about 40% of the volume of a piece of balsa is solid substance. To give a balsa tree the strength it needs to stand in the jungle, nature pumps each balsa cell full of water until they become rigid - like a car tire full of air. Green balsa wood typically contains five times as much water by weight as it has actual wood substance, compared to most hardwoods which contain very little water in relation to wood substance - it is then klin dried.

Since the reaction gives out heat, the balsa therefore gets hot (and as it becomes hotter so the reaction goes faster - there would be a reaction occuring faster than normal visable via smoke )

I wouldn't like to guess what the fumes might be, as I don't know which out of the cyanoacrylate or the balsa would break down first, and to what extent any nasties would be burnt before evaporating. The gas might be C02 and some other carbon/hydrogen molecules, maybe H2O as well.
If you always put limit on everything you do, physical or anything else. It will spread into your work and into your life. There are no limits. There are only plateaus, and you must not stay there, you must go beyond them.” - Bruce Lee.

...
 I Yearn for a world where chickens can cross the road without having their motives questioned.

Offline Tim Wescott

  • 25 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12897
Re: Smoking CA
« Reply #2 on: June 06, 2011, 09:39:14 AM »
The 'smoke' is CA monomers.  The bonding reaction gives off heat, if it goes fast enough then un-reacted CA will evaporate, then immediately condense as monomers.  Hence the smoke, and the smell even if you don't see smoke.

See http://en.wikipedia.org/wiki/Cyanoacrylate, "reaction to cotton" for an extreme example.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Steve Fitton

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2278
Re: Smoking CA
« Reply #3 on: June 06, 2011, 10:16:13 AM »
Heh heh heh, time to test "reaction to cotton"   VD~
Steve

Offline Steve Fitton

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2278
Re: Smoking CA
« Reply #4 on: June 06, 2011, 10:49:56 AM »
Well, that didn't do squat....
Steve

Offline Steve Helmick

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 10265
Re: Smoking CA
« Reply #5 on: June 06, 2011, 11:05:02 AM »
A very small dab of CA won't smoke. A large (too large) quantity will, when it finally "goes off".  Many things help set the glue "off", including humidity (exhale on it), sanding dust, baking soda, micro balloons, "kicker", etc. If you have the right combination of too much CA, some sanding dust and high humidity, you've got "CA smoke" coming your way. Don't inhale that chit! It's bad for you, even badder than gluing your finger in your ear.  LL~ Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4058
Re: Smoking CA
« Reply #6 on: June 06, 2011, 11:13:18 AM »
CA usually only smokes during the fire season in the fall.   Oh, you were referring to the glue, not the state!  LL~

We do have seasons: Earthquake, Flood, Fire and Riot.
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Dick Pacini

  • 25 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1649
Re: Smoking CA
« Reply #7 on: June 06, 2011, 11:20:12 AM »
Heh heh heh, time to test "reaction to cotton"   VD~

And strangely enough, the instructions for the P40 ARF said to use Q-tips to remove excess CA.  I saw no reaction, other than the dang Q-tips would glue themselves to the bench (or me) when I put them down.  I tell you, the whole concept of instant adhesives is really something to get used to.  In the days of yore, glue was liberally applied and then sometimes, an extra blob was issued to the joint.  After all, if you didn't have glue oozing out of all the joints, it wasn't going to be a very strong airplane. HB~>  Learning to replace that glue loogie with a tiny drop of CA that scoots into the joint, never to be seen again, is a brain boggler.
AMA 62221

Once, twice, three times a lady.  Four times and she does it for a living.  "You want me on that wall.  You need me on that wall."

Offline Andrew Borgogna

  • Andy
  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1188
Re: Smoking CA
« Reply #8 on: June 06, 2011, 11:33:22 AM »
Years ago a rep from Pacer Zap came to our club meeting and told us that only one thing kicks off CA glues that was raising the PH of the glue.  That's why way back then we used baking soda to get the glue to set when the wood was too dry.  For what it's worth I still use baking soda.
Andy
Andrew B. Borgogna

Offline Chuck Feldman

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 543
Re: Smoking CA
« Reply #9 on: June 06, 2011, 02:06:04 PM »
Dick,

Back in the day we did not smoke CA. We had grass.
Chuck Feldman
AMA 15850


Advertise Here
Tags: