Is there any article on how to use CA glues properly. I am more concerned about correct gluing techniques lets say on the SIG LT-40 wing structure. If the pieces fit tight do I use a thin CA for wicking purposes or do I use a CA+ to form more of filet in the assembly. Whats a good brand of CA's?

Most important technique : Use it in well ventilated areas and get a fan to blow the fumes away from your face, or you might develop CA allergy quickly.

For balsa-to-balsa joints, run thin CA ( with a CA tip installed) along the joint line. Don't use too much especially on surfaces that need sanding later. Then run a little medium CA to form a fillet to reinforce the joint. Ca joints are brittle, and the fillet radius reduces the stress concentration.

For ply-to-ply joints, run medium CA, followed by another run with medium or thick CA to form the fillet. For thicker CA, I like to apply some accelerator to quicken the cure. Just lightly soak a swab in accelerator and run it lightly over the joint. You could spray it on, but I find it wasteful.

Make sure that the joints butt together well as this will have impact on the joint strength later. If you have CA islands on surfaces that will be covered, you could sand it away or use a nib file (which doesn't eat the wood away )

Pacer CA works well for me. Good luck !

A great technique I picked up from the Balsa USA instructions is to glue the parts together (balsa or ply) with the thicker Ca+, then go back over the joints with thin Ca. This makes a very strong joint. If there's any gaps I go over those again with the thick Ca.

Jim

Hi Jim, Does the instruction say to apply thick ca on the mating surfaces first, then assemble ?

If the balsa parts are assembled first, then glued, I would recommend running thin ca first.

You assemble the parts first with the thick Ca, then saturate the joints with the thin afterwards.

Jim

Thanks Jim, that makes sense.

I normally do a dry assembly, ensure everthing is aligned and fitted properly, then hit the assembly with ca. I find it easier and faster that way. Again, it's my preference.

With wood glue, I have to apply first, then assemble. Since wood glue takes a loger time to set, I can still align all the pieces after assembly. I am using more wood glue now due to ca allergy, but I still use ca when I need a quick build, with all precautions of course.

If the joints fit tightly, as in say, ribs to spar, then a couple of drops of thin CA on each joint is plenty. I have never added fillets of Medium and have never had a joint fail. In my opinion, adding medium after the fact is a waste of time and money, and only adds weight. (Build to fly, not to crash.)

I have tested these joints and the wood will tear away before the joint fails.

Try applying a couple drops to a joint and watch it closely, it will "wick" along the joint, and travel a surprisingly long ways.

Definitely get the long thin tips for your CA bottle. They allow you to apply the glue more accurately, and you'll waste less.

Any of the name brand CA's are good. I've even had good luck with some "house" brands. It's really a matter of purity. The best I've used to date is Jet thin CA. I had a 2 ounce bottle that lasted through construction of two planes, plus some repairs, over an 8 month period! No special storage other than replacing the cap immediately after every use.
Dennis-

I appreciate everyones response. One more question. Does pre-gluing lets say on a grain end piece of balsa really necessary to form a strong joint so that the glue does not soak in resulting in a weak joint?

DO NOT preglue with thin CA! The joint must be seated firmly before applying the CA. Thin cures so quickly that it's doubtful you will get the pieces properly aligned before the CA sets. I wouldn't even recommend pregluing with medium CA, but it's okay with thick.

Here's another technique for you...

If you are gluing something like a doubler, that requires a lot of glue, just put a few strategically placed drops of CA and smear carpenter's glue around the rest of it. The CA will hold it in place while the carpenter's glue dries. Saves CA and money! (Makes a better glue joint too.)

CA clamp ! Neat idea. How much margin do you need between the ca spot and the other adhesive ? I guess the ca would not work well if it gets mixed with the other.

You have repeated what I have read in other posts, that CA joints are brittle. Well several days ago in my shop, I turned over a bottle of thin CA without noticing. Today I went to pick it up off my workbench and the CA had flowed around the bottle gluing it firmly to the paper I had covered my work surface with. I cut the hardened glue away from the bottle and was suprised to find that it is quite flexible. It was hard to cut and was extremely tough but could be bent back over itself without breaking. The hardened glue was at least as strong and less brittle than epoxy. I may have to reevaluate my understanding of CA. Some of the weakness seen in CA joints may be as much joint fit up as it is due to the CA.

I'm a geezer, I admit it... I remember reading in Popular Science about CA when it was first invented. Then it got marketed as a wonderful adhesive, but only for non-porous surfaces. I got an RTF trainer about a month ago, and an ARF Ultra Stick kit a couple weeks ago. I was shocked to see people bonding porous balsa and other wood with CA. Then again, it always worked good on my tennis shoes... I've since bought super thin (hinges) and gap filling CA and some mid-cure Epoxy. Do people use plain wood glue anymore? Like the real old stinky stuff made from horse bones? How about Liquid Nails for projects and such? Or is CA and Epoxy the best of the best, and the old stuff has no advantages? - Joe

I've been wondering for a while now and I guess this is a good thread to ask my question :
What is CA? Looks like some sort of fast drying glue when I read the posts. I know epoxy, but whats the difference?
Is it an abbreviation for something?
thanks

A10......forgive me if I'm oversimplifying the answer to your question. It's early, and my brain is not quite working yet.

'CA' is an abbreviation for 'cyanoacrylate ester'.
Commonly known under the trade name of 'Super Glue' to most non-hobby enthusists. "Super Glue" is a pretty generic, low quality type product, but chemically the same as what we use in our little hobby here.
It comes in a number of formulations, from a thin type, which wicks into pourous materials, and dries quickly, to a thick, nearly gel like formulation, which is VERY strong, and takes a few moments to cure, and a few types in between.
This adhesive is used in numerous ways......the folks that posted before me have kindly pointed many of them out.

Epoxy refers to any number of catalyst type adhesives that use a mix of a hardner agent, and a resin agent. When mixed together, a catalyst reaction takes place (you can feel the heat given off by this reaction...try holding your mixing cup in your hand after mixing up a batch), and the mixture begins to solidify. Many applications for this type of adhesive; fuse to bulkhead joints, applying fiberglass cloth to , say, a wing, to name a few.

Both products have many applications in our hobby, and I'm sure you have used both for many of them.

I think many would agree, but I believe the 'ZAP' line of CA products are the best ones out there.

Brg,
Jeff

thanks for the info jkirkon, now at least I know what ppl are talking about whenCA is mentioned. Its that stuff I've glued my fingers together with and also that product that caused my eyes to be irritated when I wanted to use it to close an hole in a football. Good I've grown up now, but the self pain inflicting hasnt stopped : now I cut my fingers with the hobby knife, ...
Thanks again, sorry for going somewhat off topic

When gluing those small pieces inside a tight space, the only clamp that you can use ( your fingers) will most likely end up being glued to the piece better than the piece is glued to the airplane! So what I have been doing is applying a very thin layer of Petroleum Jelly to the finger tips I am going to use to set and clamp the piece in place. Being extremely careful not to get any of it on the gluing surfaces.

When I'm sure the glue is set, I can remove my hand without leaving any DNA behind or ripping the piece back out.

All great ideas. has anyone tried CA on thier fingers. doesnt matter what kind you use thin thick medium, its all the same. your screwed !!!!!!!

I was working on a plane holding a wing rib in position. Meanwile trying to remove the stuck cap from a bottle of thin CA with my teeth[X(] Please don't try this at home
As Murpheys law would dictate; the neck of the bottle snapped off, and I quickly found my "yap glued shut"
At the time, there was a Revco drug store across the street. So I ran in and grabbed some nail polish remover (acetone).
At the checkout, I was using it to try to release the glue from my mouth with the product. Then the local police showed up. Called by a cashier, concerned by my behaviour[sm=tongue.gif]

FREDSTERMAN:

AWESOME DUDE... I live about 40 miles from NASA in Florida. If you ever need a good paying job try that place, that are always looking for some good ROCKET SCIENCETIST!!!!!!!!!!


Thanks for a good laugh.