I've got a question for you guys, which mewtod is better and if you have an alternative, lets hear it as well.


After fitting my parts I tack everything together with CA and then go back and hit all joints with elmers wood glue. Is this joint stonger or would it be stronger if I used strictly CA?


Thanks for the input,


Neo

I do it the same way you described. I use a dental syringe to meter the glue exactly where I want it and cover every joint. It gives you a nice glue line and not too much. Works really well. You can get them for next to nothing at a med supply place. I have a box of them, and when I fill it, I tip it upright to get the air out, and store it in a cup of water to keep it from plugging the tip up. Works great and makes for a really strong joint.

Gee I hate having to do things twice! For the most part, I try to get the right amount of glue (Titebond II usually) the first time. Extra glueing is extra time and extra weight. I even scrape/wipe away some of the excess squeezeout.

Anybody KNOW if adding fillets of GLUE actually adds much strength?

I have been doing it for over 27 years and never had one come apart so it must work. I build with zap and tack it all together and then glue all the joints with wood glue. It doesn't add much time. I build a gentle lady in a night, covered it the next and never took less than third with it in a contest, electra the same build time, just built a Something extra that took about 4 nights, most of which was talking on the phone and not doing much building. Takes me longer to cover it than to build it.

The fillets on balsa to balsa are great, ribs to spars work well too. I wouldn't do it on firewalls though.

After some 26 years of RC building, I almost stick exclusively with CA. Sometimes thin, on tight joints, not on plywood or lite ply, and the normal thick for most others. I do use slow dry epoxy for firewalls and landing gear plates on the larger planes. My current fleet of 19 planes includes 120 and 1.5 glow aerobatic airplanes.

The next time you crash a plane, try to take apart the CA joints. Or make some test joints and allow them a full 24 hours to really cure, then destroy the joint and see if you don't break wood instead of the glue joint.

As Don Lowe said one time when the TOC was just going to the larger airplanes, you could build the whole plane with CA and not worry.

Clair

They are stronger than heck. I have built many planes with just instant glue. I have some that are built that way that are pretty old and they hold together too. I prefer to double glue like I stated in the earlier posts, but all CA works well too. Lots of people doing it.

Yep, strictly CA joints are plenty strong assuming the joints are tight. Thin CA will not fill gaps, so keep it in mind.

"Is this joint stonger or would it be stronger if I used strictly CA? "

You asked which is stronger. Obviously, using both glues will be stronger, but using either one alone is a toss up.
Dennis-

Most common model glues are stronger than the wood itself. This includes CA, aliphatic, polyU, epoxy. The first trick to a strong joint is the tightness of the fit. The second is penetration into the joint. Here, thin ca excels with balsa. Thicker ca's may fill gaps, but it penetrates less. With ply and spruce, CA penetrates less than aliphatic or epoxy. The glue dries faster than the wicking time. Use no less than 30 minute epoxy and don't use Pica Gluit. Gluit is altered to make its dry time very fast. Selecting the right glue based on its penetration is more important than brand.

Good answer MikeS.

A good method to get a good joint with aliphatics is to coat both parts, let them sit for a while to allow the glue to penetrate, then put them together...wiping off any excess.