Hello, I started a thread about the CA fumes not even noticing another similar thread just before mine. Without continueing THAT subject...I would like to know how you guys are glueing "SOME" kits
without using CA. I am speaking of... not just the glue but PROCEDURE too!!!
Example...... this little Sig LT-25,(and most of the Sig 120 I just finished), calls for a "DRY ASSEMBLY" first. You line everything up and then hit it with CA. This kit.... and maybe others?, had 90% locking parts in the wing, that just seems like it HAD to be done their way. The shear webs fore and aft, are all in one piece with notches that HAVE to lock into the ribs. (from the bottom). So....I couln't do it the old fashioned way of setting down one rib at a time. There just isn't reasonable time to put this together with glue on all the parts without any glue starting to set up. AND... just "surface glueing" with all the other types of glues on a dry assembled wing or fuse, just would not be good procedure. OR... am I missing somthing here??? NOTE......
On my 4* 120..... I did cheat on the pre-assembled fuse and applied epoxy to the firewall, and a couple forward formers. I LOVE epoxy!!! Putting aside the fumes....I just don't trust CA like I do Titebond and epoxy.....lownslo.....

when ca is used correctly, it should never fail at the joint, only beside the joint. one thing not to do is to tough the parts to be glued with your fingers, you are now adding your oil into the glue joint, which will now decrease the strength by a lot. also, for a good strong joint, the parts should be snug, a loose fit is no good. try to avoid sanding a joint that is to be glued, you are covering the wood pores with sawdust and foreign materials being pressed into the wood, now decreases the strength, you should cut or saw.
glue is only reguired on the joint itself, when you apply glue on the outside all you are adding is weight, there is no structural strength in glue. all that glue does is bond two surfaces together.

take fiberglass for example, the epoxt resin when hard has no strength, it is brittle. so if you have glue on the outside of a joint, you can just peel it off.


just try to have a good tight joint, free from foreign objects, and you'll have one good glue joint. ca is good for most of the model, in high strength areas always use epoxy. for a firewall, never use ca.

good luck,

GB

If you mean you don't trust CA because the fumes will make you sick, I can understand you. But if you're saying you don't trust it to make a good joint, I can't understand that. CA (like most glues) will make a joint stronger than the wood, and there's not much point in stronger than that. Further, CA is almost foolproof, because it sinks so deeply into the wood.

On the issue of the kits being designed (and the instructions too) for CA, I think you are correct. The job of the kit designer is to produce a kit that maximizes the chances of the builder creating a great airplane. The modern designs that rely on dry assembly, and then count on the CA to seep into the joint have really revolutionized kit building. It the past, great skill was required to keep everything square and parallel. Now the kits are designed so it's almost impossible to build out of square, and the assumed use of CA makes that possible. Further, the kits go together faster. (I wish someone revolutionized covering!)

I would guess that most people who build kits just use CA. And many who try to avoid it, still use it sometimes, when it's the most logical (or only) choice. Where you have balsa parts tightly assembled dry, thin CA is pretty much the only choice.

On the positive sign, you can get the gluing done faster, and get out of the room until the fumes dissipate.

I believe your right, many kits with the interlocking parts are sort of designed for use with CA. Could you do your gluing out side while still wearing gloves, mask, etc.

I would have no concern about the strength using a medium CA in this kind of assembly. The medium will wick into the marginal fit joints. Everyone uses epoxy in the engine mount area, but one of the main reasons for this is the resistance of epoxy to fuel. Of course the cured strength (tensile strength) of say a filet of epoxy is much stronger than CA, so anything that is a sloppy fit epoxy is best. Epoxy is better where there is a lot of vibration as well, so again good for the engine mount.

I am unable to use regular CA, so I use odorless where necessary, but am not excited about $10/oz. glue. On tight fitting joints I have loaded a syringe(no needle) with yellow carpenter's glue and then forced small amounts into the corners/crevices/wherever. The glue is forced into the tightest spaces. I have also used polyurethane glue and squeezed it into corners beside ribs. It expands as it cures and the fillets seem to offer additonal strength. This is based on my very limited building.

Some aliphatic glues are as thin as milk, you can apply them pretty much like CA. Of course they won't cure in seconds, but that's not always a problem.

Personally I always use SuperPhatic, it is ideal for this sort of application. In fact, the description on their website says: "Highly penetrating yellow aliphatic glue with "wicking" action. Penetrates joints after assembly ;dries fast and bonds wood, foam, paper.
Penetrates and bonds pre-assembled joints.Ideal for slot together kits."

http://www.deluxematerials.com/aero-products.html

Hello guys, and THANKS for your replies. To pinball.... I know deep down your thoughts ARE correct about CA's strengh. Were I have a problem with it's use is in any "marginal" fit of parts situation. I will continue to use CA, (in selected, and required situations only), but be MUCH MORE careful than I was in my first estensive use of CA. On those loose fitting parts, or gaps, I will trust epoxy or Titebond more than thick CA.
To those that offered alternative glues.....my sincere thanks..... I will be experimenting on my next plane!! ....lownslo...

Bob

This SuperPhatic glue sounds like a terrific solution to your problem. I plan on getting some myself, as I'm not in love with CA odors either, but so far no allergy.

Morning lownslo,any time the material has a loose fit it is a weak joint regardless of which glue is used as a filler.

I wouldn't be afraid of CA. I have built many .60 and up size planes entirely of CA. Never had a part fail yet. I use epoxy on some cent wing joints and firewalls, but CA for the most part. I have built some planes of entirely CA. Never had a worry.

I agree with TerrellFlyer. Marginal fit is not good with any glue. Just cut a new part, or stick little bits of balsa in the gap. That's what so nice about CA. It will sink into all the cracks.