I am getting ready to install some CA hinges on my second plane. My first ARF plane I built said to drill a 3/32 hole in the hinge slot about a half inch and clean the slot out so the CA can wick into the slot. The instructions for my second plane doesn't mention this drilling step although the directions are not the best. I have not drilled any holes in the hinges slots yet and wanted to make sure that if I don't that I wouldn't be making a big mistake by not drilling the holes.

Thanks in advance.

Harley, here's the procedure I use on all ca hinges. After the hinge slot is cut in the flying and control surfaces, make it a tight fit, I use a sharpened piece of 1/16th piano wire and poke a hole in the center of the hinge slot on both surfaces. I then mark a centerline on each hinge. Then slide the hinges up to the centerline on the flying surfaces. Put a couple of drops of thin ca on the top and bottom of each hinge. I then slide each control surface on the hinges. After flexing the control surface to get the proper gap I then put a couple of drops of ca on the top and bottom of each hinge on the control surface side. The hole in the center of each hinge slot allows the ca to wick in completely.
Hope this helps

I had a couple CA hinge failures when I first started using the stuff. If you put
too much CA on the hinges, they get too hard, and break in a short time.

Now I use only three drops on each side, 6 drops total per hinge, and have not
had a failure since. The CA seems to wick in nicely. I have not used the hole technique.

I trim the covering away around the hinge slots, so it wicks right in.

FBD.

Dave, all the hole does is let the ca wick in a little deeper, maybe. It's a simple step for a little perceived peace of mind.

I agree that it could well be of benefit. [sm=thumbup.gif]

Dave.

I might miss out pinning fuzzy mylar hinges and rely on the cyano.

But buy some cocktail sticks drill a 1/16 th hole from underneath and stop after drilling through the hinge. You soon get the touch. Put a drop of slow cyano in the hole and push in the cocktail stick. Wait till the cyano goes off and use side cutters to clip off the excess. If you want a flush finish grind the excess of with your Dremel. Takes longer to describe than do.

Belt and braces are good on this mission critical item.

WARNING ALLWAYS PIN SHINY MYLAR HINGES. WARNING

Tashley has the proper technique. Properly installed CA hinges do not need to be pinned and will last the life of the plane.

j.duncker, I didn't know anyone still made ca type hinges without the backing material applied. I certainly wouldn't use them now as the "backed" hinges bond so well to balsa. I do know this, if you slot for your hinges properly and install them properly and put a pull test on them you will remove a large chunk of balsa when they come out.

I did a test with one drop of CA and a hinge in a scrap of balsa....

....I could not pull it out.

Dave.

I would never ever ever "tack glue" a CA hinge in place. what that effectively does is seal the gap between the hinge and the wood which will not let further "wicking" at a later time. Mark the center of the hinge. If you cannot pinch the trailing edge to keep the hinge from moving, insert a pin through the center of the hinge to keep it in place as you slide the control surface on. Remove the pin prior to CA application. Do one side of the hinge at one time. Drop CA and as it wicks in, immediately put another drop until the wicking action takes several seconds to wick and then stop. Turn over and do the other side. Move on to the next hinge. It is very important that once you start applying CA, finish the application for that hinge.

I cut a slot with a exacto knife, just a slice, install the hinge, put a t-pin on the front edge down through the middle; slide on the control surface, add 2 drops of ca to top and 1 drop to the bottom using thin ca. you will never pull them out, I have tried.