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CA (and other delights!)
#1
Wink 
OK, when I started in this crazy hobby two years ago, I depended upon Elmer's Yellow Carpentry glue (and still do) for my low power builds.

But very quickly, I kept running into advice from old hands to use "CA" or "CA this" or "CA your balsa", etc.

It became apparent to me that this was "superglue" by the nick-name for the chemical that it represents.
But still, I resisted, until I saw an old hand repair my balsa wood fin in the field with a combination of a CA squirt and then a spray "hardener".  He pronounced it "fit to fly" immediately.  And he was right!

So, I invested in a bottle of "thick CA" with a needle nose applicator on it.  I used it a couple of times, but then discovered that it was gluing the needle nose cap onto the bottle, making it useless.

I went to a hobby store and bought another needle nose applicator, but this time, stored the bottle in an empty JIF jar, with the lid screwed on and a decanting (humidity busting) packet that had come with some electronic something-or-other.  This seemed to work well, until someone knocked the JIF jar over, and the bottle laid on it's side in the jar.

Yes, it leaked somehow, and almost refused to come back out of the jar.

I bought a smaller, half an ounce bottle of THIN CA and laid it in the top of my tackle box to take along to club launches.

Though I didn't get to last month's launch, I was shocked to see at this launch, when I needed it to repair a cracked fin on my Goblin rocket, that this bottle had not only leaked from under the screw top (not out the needle nose) and adheared itself to a plastic ball point pen that it was laying next to.  By prying it  up, I was able to get it free, plus about an inch of the plastic pen that broke off with the bottle. The pen remains glued tight to the tray in my tackle box.

But worse yet, despite getting the screw top head off the CA bottle with a pair of channel locks, a tooth pick has failed to help me get any CA out... it's all turned to a thick jelly inside, and refuses to spread or apply at all.

So now, I  am left with the point of this posting.
IS there a shelf life to CA?

Is it known for leaking out of a plastic squeeze bottle?

How often do you buy new CA, and in what quantity?

Is there any way to revive an "old" or "Turned" bottle?

What is best for rocketry?  Thin? Thick? or other 'brand'?

What "brand" CA do you prefer?  And in what quantity?

And what do you think of this accelerator stuff?  Is it trustworth?  Does it harden at the risk of brittleness? Or other drawback?

Thanks for any insight and advice, guys!
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#2
I sure hope someone with experience on this posts, as CA is not my favorite for what you described. On mod rocks (I must admit i dont build many of those anymore) I used a rubbery cement rather than a quick set or elmers wood. Elmers was not good when wet and to brittle.


Bill Clune L3 | NAR#88583
Been a launch Director
Founded a Club
MARS Club|SRC|MDRA - Forever
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#3
First up -
Don't use Super Glues to glue on fins, launch lugs or engine mounts.
In construction it's only good for strengthening up a lip on a body tube or lightly tacking things in place.
Follow up with yellow or white glue.
Never use Super Glue on knots or shroud line knots. It runs up the line making it brittle.
Super Glues get hard and brittle over time.
A older rocket constructed with Super Glue will have parts pop off during boost and on landing.

IS there a shelf life to CA?
To extend it's life, keep it cold in the refrigerator.
Don't store it in the door, it might fall over and leak.

Is it known for leaking out of a plastic squeeze bottle?
Only when it's turned on its side! Don't let in fall over.

How often do you buy new CA, and in what quantity?
I buy small bottles as needed.

"Is there any way to revive an "old" or "Turned" bottle?"
Not that I know of.

What is best for rocketry?  Thin? Thick? or other 'brand'?
I have thin and medium. I buy the thin in a small bottle at a hobby store.
Unless you use a LOT of thin super glue, buy it in small bottles.
If the smaller bottle dries out, you are only losing money on a smaller bottle.
The medium I buy at the dollar tree store, two small bottles for a dollar.

What "brand" CA do you prefer?  And in what quantity?
You'll find your hobby stores name imprinted on Bob Smith CA.
Bob Smith makes all the different styles of CA glue.
The stuff from the Dollar Tree store is the original Super Glue brand.

And what do you think of this accelerator stuff?  Is it trustworth?  Does it harden at the risk of brittleness? Or other drawback?
I've never needed or used the accelerator. Thin CA dries pretty fast by itself. Medium CA just takes a longer time to dry.

You might try to find some Teflon tubing to slip into the pointed nozzle end.
You will have to cut a little more off the nozzle end to get the Teflon tube in.
Cut off 1/2" of Teflon tube and use tweezers to push it into the new cut hole.
When the tip gets logged, use a wire (I use a "B" string off a guitar) to clear it.
When the tube gets bad, pull it out and put a new length in.

When using the Teflon tube, you don't put the cap over the nozzle.
Put it in the fridge withe the tube in place and it should be fine.
Hans "Chris" Michielssen
Old/New NAR # 19086 SR
www.modelrocketbuilding.blogspot.com

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#4
CA is, IMHO, only good for 1) hardening balsa parts and 2) quickie field repairs when you want to fly the model again immediately and don't have time for a "proper" repair. I know some will disagree with that statement, but that's their opinion, and this is mine.

CA (cyanoacrylate glue, or "super glue" to the uninitiated) gets brittle over time and while it has terrific strength in tension, it is easily broken in "shear"-- exactly the kinds of forces trying to tear fins off aerodynamically (and via acceleration) during flight, and trying to pop the fins off at landing when they hit the ground first and take the shock of the entire rocket landing through the fin joint.

Balsa hardening is the method of making the balsa tougher via soaking CA into the wood grain-- the ultra-thin watery types of CA will quickly and easily wick deep into the large pores of balsa wood, going deep into the wood before curing, which basically turns the balsa into a type of "composite material", as the CA "resin" hardens in the balsa wood "substrate", sorta like the glass "cat hair" and epoxy resin used to make fiberglass... The CA hardens inside the wood, binding the wood fibers together and making it harder (but not bulletproof-- the balsa does have a breaking point, as everything does).

Attaching fins or launch lugs or other structural components to the rocket using CA is, IMHO, asking for it to fail at a critical moment. Some folks use CA to "tack the fins on" and then use wood glue or white glue to complete the joint, thinking they're getting a better bond and the strength of the wood glue joint. In fact, the CA has in fact wicked into the wood pores and "sealed them off", preventing the wood glue from wicking into the wood pores and making a good strong joint-- in effect, it's basically the same as trying to glue plastic fins on with wood glue at that point...

The strongest joint you can get with balsa and paper joints (as in fins to tube joint), is with yellow wood glue. If you want the convenience of an "instant bond" like you'd get with CA, with unparalleled strength, use a double-glue joint. Apply a thin layer of wood glue to the fin root edge, and another thin layer on the tube where the fin will attach (after lightly sanding the tube to rough up the glassine for maximum strength if desired) and allow that to dry until it's tacked up (not quite dry, although if it dries it's okay). Then apply a second thin layer of glue to the fin root, carefully align it, and then lower it onto the tube and hold it for 20 seconds... the fin will "lock on" to the tube almost instantly, so align it carefully before allowing the parts to touch. The parts will glue together nearly instantly, eliminating the need for complex and/or expensive fin jigs to hold the fins on while slobbery yellow glue runs everywhere. Double-glue joints are stronger than the materials you're gluing together... the balsa will break or the outer layers of the tubes will rip off before the glue joint ever lets go... and once the joint is stronger than the materials, there's no sense in worrying about making a stronger joint-- a chain is no stronger than its weakest link, after all...

When I use CA, I get the ultra-thin stuff in the pink bottle from Hobby Lobby. Basically, get the smallest bottle you can-- the stuff has a notoriously short lifespan. No matter HOW carefully you pack it away, using sealed jars, refrigeration, dessicants to absorb moisture, etc, it's still going to eventually thicken and/or harden... once that process starts, forget it... it's done. There's no way to "undo" it once it starts to gel or has outright hardened. Basically, the timer starts running the moment you open the bottle... you can slow it down, but you can't really completely stop it from going to pot eventually.

I've heard of some folks only using the little dinky tubes of 99 cent stuff from the dollar store... personally I prefer the little pink bottles of ultra-thin CA from Hobby Lobby-- it soaks right into balsa wood like water into a paper towel, and hardens it up nicely. It similarly will harden paper transitions and cones and other paper parts and make them MUCH tougher and stronger. There's really no sense in buying big bottles of CA-- it will harden and go to pot before you use up even half of it, unless you use it for everything (not recommended) and build 30 models a month...

For paper-to-paper joints, the strongest joint is actually made with a good PVA (white) glue. It's also less prone to shrinkage than yellow glue, which can cause a "coke bottle" effect when gluing centering rings or motor mounts inside body tubes... For gluing in tight fitting couplers or long/complex motor mounts (stuffer tube types come to mind), one needs a good NOT TOO TIGHT fit and LOTS of slobbery white glue to ensure things don't "freeze up" halfway through the installation. Epoxy, since it will basically "lubricate the joint" and doesn't rely on evaporation or absorption of the 'solvent' (water in the case of yellow/white glues) but instead on a chemical reaction between resin and hardener to cure, it ensures the joint won't "lock up" before the parts are in their final position. Of course epoxy comes with it's own set of problems, so that's one of the few things I'll use it for.

For most joints, wood and/or white glue is still the best and strongest adhesive available for the typical balsa and paper tube rocketry materials. For plastics, epoxy and even some plastic glues are preferable. The main thing is use the right adhesive, the right way, for the right materials...

Other than that, I don't use the stuff (CA).

Later! OL JR Smile

Later! OL JR Smile

(10-22-2015, 10:04 AM)hcmbanjo Wrote: (snip)
And what do you think of this accelerator stuff?  Is it trustworth?  Does it harden at the risk of brittleness? Or other drawback?
I've never needed or used the accelerator. Thin CA dries pretty fast by itself. Medium CA just takes a longer time to dry.

Yes, accelerator or "kicker" will cause CA to be even more brittle than it normally is, or to get brittle faster. 

I picked up a bottle one time cheap for S&G's, but other than gluing on tiny detail parts on scale models I don't use the stuff (CA or kicker). 

Later!  OL JR Smile
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#5
+1 to what the others said. I now only use the thin. It's good for strengthening parts, making sure the edges of papered fins stay in place, repairing cracked fillets and BT repairs. I'll also add that the kicker not only sets the glue immediately but it also makes the glue surface kinda gnarly. Especially with thin CA, you often get a thin layer around the part you are gluing. If you use accelerator, you will need to sand those areas. And the stuff is hard to sand.

Oh, I also get thicker CA in tiny little tubes to keep in my range box. That way you use one and toss what you don't need. I find this in the check out aisle at my local computer store. They last several seasons but, as I found out this year, even unopened it has a shelf life.
Member of MDRA, NAR and NARHAMS;
Level-2 certified but mostly fly G and under;
Volunteer compiler of manufacturer's news for ROCKETS Magazine.
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#6
"CA is, IMHO, only good for 1) hardening balsa parts and 2) quickie field repairs when you want to fly the model again immediately and don't have time for a "proper" repair. I know some will disagree with that statement, but that's their opinion, and this is mine."

I've also used thin CA to stiffen up a card stock shroud. But I keep it away from the edges to be glued.
You are right it can come in handy for quick field repairs, but it's not a permanent bond.

"Some folks use CA to "tack the fins on" and then use wood glue or white glue to complete the joint, thinking they're getting a better bond and the strength of the wood glue joint. In fact, the CA has in fact wicked into the wood pores and "sealed them off", preventing the wood glue from wicking into the wood pores and making a good strong joint-- in effect, it's basically the same as trying to glue plastic fins on with wood glue at that point... "

I should have gone into more detail. I don't use CA to tack on fins -
Sometimes when you are "bending" a piece of wood to go around a curved area (like a plank on a ship or the intakes on the QCC Explorer) CA works well.
Again you are right, CA glue can seal up a root edge of a fin preventing the white or yellow glue from soaking in.

"When I use CA, I get the ultra-thin stuff in the pink bottle from Hobby Lobby. Basically, get the smallest bottle you can-- the stuff has a notoriously short lifespan. No matter HOW carefully you pack it away, using sealed jars, refrigeration, dessicants to absorb moisture, etc, it's still going to eventually thicken and/or harden... once that process starts, forget it... it's done. There's no way to "undo" it once it starts to gel or has outright hardened. Basically, the timer starts running the moment you open the bottle... you can slow it down, but you can't really completely stop it from going to pot eventually."

I've had great luck keeping CA usable by storing it in the refrigerator.
I have two small 1/2 oz. bottles of thin CA in my refrigerator, both have Teflon tubes inserted into the nozzle tip.
The blue cap is not on the nozzle, just the open Teflon tube.
I rarely use them. I just checked them and both are still liquid, flowing and did stick two fingers together.
The two bottles are over a year old.

"For most joints, wood and/or white glue is still the best and strongest adhesive available for the typical balsa and paper tube rocketry materials. For plastics, epoxy and even some plastic glues are preferable. The main thing is use the right adhesive, the right way, for the right materials..."

Well put and Agreed!
Hans "Chris" Michielssen
Old/New NAR # 19086 SR
www.modelrocketbuilding.blogspot.com

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#7
Great information and tips, guys. This was just what I was looking for.
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#8
(10-22-2015, 05:21 PM)Kirk G Wrote: Great information and tips, guys.  This was just what I was looking for.

Kirk,

Not sure where you live, but higher humidity could be your enemy.  I live in Colorado and its pretty much bone dry here.  I used to keep my CA in my "shop refrigerator" in the basement, and it lasted FOREVER.  I jut now keep it in my workshop in the basement, and it basically still seems to last forever.  

I use it more in woodturning, where I want to toughen up spalted woods (soft, decayed woods caused by fungi).  I've turned woods that could be crsuhed into pieces by hand, and after CA, can be turned pretty easily.  I've also used it to toughen soft balsa for turning nose cones, or justt to toughen up fins.

CA has its use, but for me, seldom gets used for construction.
Lee
NAR 55948, L2
In Build:   Estes Saturn 1B
Next: complete Semroc Mars Lander, upscaled Orbital Transport
In Finishing:  Interceptor-E 
______________________
Rocket Pictures
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#9
I never have had problems with the thin going bad. I just keep it upright and squeeze some of the extra air out of the bottle before I pop the cap back on.

I generally don't keep any around but I have had good luck with the black rubberized CA on plastic-to-plastic applications. Almost forgot about that stuff!
Member of MDRA, NAR and NARHAMS;
Level-2 certified but mostly fly G and under;
Volunteer compiler of manufacturer's news for ROCKETS Magazine.
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#10
Quote:Kirk,
Not sure where you live, but higher humidity could be your enemy.  I live in Colorado and its pretty much bone dry here.  I used to keep my CA in my "shop refrigerator" in the basement, and it lasted FOREVER.  I jut now keep it in my workshop in the basement, and it basically still seems to last forever.

I live in Florida, very humid here. Stored in the fridge the CA bottles seem to last a long time.

Quote:I never have had problems with the thin going bad. I just keep it upright and squeeze some of the extra air out of the bottle before I pop the cap back on.

That's a good point Dick. After use I hold the bottle upright and squeeze out any glue left in the nozzle tip into a paper towel.
Hans "Chris" Michielssen
Old/New NAR # 19086 SR
www.modelrocketbuilding.blogspot.com

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