CA HINGE INSTALL HELP
 

I'v read several methods of installing CA hinges. MinnFlyers suggests CAing all the hinges on one side while the surfaces are flexed and then turning it over and doing the other side the same way but with the surface flexed the other direction. Another suggestion is to :

For glue application take one hinge at a time. Put a drop using the fine capillary tip on the glue bottle. Place one drop at a time on one side of the hinge and watch for it to soak into the fiber hinge. Too Much glue will run down the hinge line and make a mess only a small drop right on the fiber of the CA hinge. This drop will soak in, and then add another drop. Continue this process until the drops don’t soak in as fast. Then flip it over and drop by drop the same process on the other side of the same hinge. Never use Accelerator this will make the hinges brittle.
Once the hinge can’t take anymore CA move to the next hinge. Again drop by drop until it will not soak up anymore… Be sure to apply some to both sides of the hinge in the drop by drop manner. The reason to do one hinge at a time is if the CA kicks off before the hinge gets saturated it will not let anymore glue in and will not have enough for the bond. The idea is to keep it wet and absorbing until it can’t absorb anymore. Then it has enough….So watch the drop soak in then apply another immediately until it is saturated. Once you have all the hinges on a surface glued set it aside. Don’t go messing around with the moving the hinge just let it cure.

My question is whos right ? I can see the reason for wanting to work as fast as possible since CA sets up quickly but is the ONE hinge at a time method the right one or MINNS ? Also is it necessary to push the surfaces together AFTER the centering pins are removed before CAing ? And how long do you let everthing set before you flex the hinges and loosen them up ?

Thanks in advance for your help ....................

RE: CA HINGE INSTALL HELP
 

Minn Flyer also is wise and correct in recommending you slit and remove the covering on either side of the hinge slot for 1/16" and to drill a 3/32" hole into the center of the hinge slot. If you do this it will accept the five-or six drops of CA per side with no run-off and form a very strong bond and saturate the wood, also strengthening it.

As far as one or many per side - with a large wing it is much easier to set the wing down and hit all the hinges on one side, then flip it and do the other side. Is it more "right" than one at a time? Can't say. I believe both would work, but I do all on one side and then flip and repeat. There is a membrane (Mylar?) in the center layer of the CA hinges that does not allow the CA to pass through to the other side.

Yes, push the control surfaces together BUT flex them to the max away from the side you are working on. This will guarantee full range of motion. If you add the CA to a flat surface and try and flex it later it may "bottom out" because the hinge line was too tight. Variations in hinge slot's center-line and straightness of the hinge line will cause this.

Once I have finished both sides I flex the hinges immediately and to their full travel.

RE: CA HINGE INSTALL HELP
 

Do like Minn said. After you remove the pins, push the surfaces together to make the gap as tight as possible. Then gently flex the surface to it's max. I say gently, because the gap will probably open up a bit but you don't want it to get excessive. Then slowly drip the CA into the first hinge. Five or six drops are enough. Go to the next hinge and so forth until you've done all of them on one side. Then turn the wing or fuse over and repeat the process on the other side. Set it aside for a while, an hour or so. CA that is still exposed to the air can take a surprisingly long time to cure. You don't want to glue yourself to the plane.[:@] After the CA is cured, flex the surface back and forth a few times to loosen it up. Once the CA is cured, don't add more, 'just to make sure', you'll just weaken the hinge. If you over do it and some CA runs down the covering, use acetone to remove it. Acetone won't hurt the covering at all.
Paul

RE: CA HINGE INSTALL HELP
 

I read several posts on installing CA hinges and I find the descriptions confusing. Lets talk about one aileron hinge only. With the top of the wing facing up I apply several drops to the wing side and several drops to the
Elevator side OK got that is this hinge completely installed?

This is were it is unclear do I need to turn the wing upside down and more glue to that same hinge on the wing side and the elevator side again only from the bottom now?

RE: CA HINGE INSTALL HELP
 

This is where I get confused, two very good and informative responses - and I thank you both - but one says he flexes the hinges immediately after doing both sides , and the other says he lays it aside for an hour or so before he begins flexing. I would think this step of the process would be as important as the gluing itself. What I'm not catching I guess, and I apologize for my lack of understanding here, is how long does it take for CA to comletely dry, and does workng the hinge before it does weaken the joint. Your flexing the joint immediately in my opinion by the fact your bending the surface to a max position to get the glue in the joint, and then bending back the other way for the other side. Still confused. Maybe I just need to glue the d__n thing and get on with it.

RE: CA HINGE INSTALL HELP
 

I think you're trying to make more out of this than there really is. It's not rocket science. Basically you put the hinge in, glue one side, turn the wing over, glue the other side and you're done. Just go do a couple hinges and you'll figure it out.:)
Paul

RE: CA HINGE INSTALL HELP
 

I have a little bit different method:

There is a slot for a hinge and the hinge is sitting inside.

I push a pin through the surface and the hinge to hold it in place for the right gap between the surfaces.

No CA yet, i drill through the surface through the CA hinge with a drill bit.
Then I insert a tooth pick all the way through.

Spray some CA kicker on the CA hinge from the exposed section between the surfaces.
(can do without the kicker as well but you need to play with the surfaces while the CA is curing)

Then I drip thin CA through the tooth pick!!!

I play the surfaces just to make sure they move freely every few minutes for about an hour.

I cut the excess tooth picks and sand flash.

This way I prevent from the CA hinges to harden from the CA and brake.

This method is good for hinging first then sanding and covering over the hinge line.

RE: CA HINGE INSTALL HELP
 

Do it MinnFlyer's way. The only reason you insert a pin in the middle of the hinge is to make certain the same amount of hinge materiel is used on each end. If your CA hinge is slotted in the center already you're good to go. If your CA hing materiel is solid its a good idea to drill a small hole in the middle of your hinge slot (on both surfaces) to help it wick in better. This is not absolutely necessary but doesn't hurt and might help.

After you have all CA hinges in place, centered, and make sure each one is truly in both sides in their slots and you are satisfied with the fit...then sit down where you are comfortable, have good lighting, and can see clearly and flex the control surface as far as you can and still not expand the gap between the surfaces. In the case of the aileron for instance; hold it such that the wing is also tilted up so that the CA will run down into the slot. Dribble some CA onto each hinge on the wing side, the while holding everything together and still bent..tilt so that the aileron is now down and CA will run down into the hinge...and dribble some on each hinge.

Once all are done and you've held it together with the surface flexed the entire time; Flip the wing over, flex the other way, hold it, and dribble some CA on each hinge while tilting the assembly so that the CA will run down into the slot you intend.

Once all of them are CA'd in and you've held it so that everything has set up firmly, flex the surface back and forth to make certain it will flex without undue strain on the servo.

Do only one aileron at a time. Do each surface the same way. Don't dawdle yet don't rush either. You don't want the CA to set up too much before you apply to the other side since that may weaken the connection yet you don't want to rush so fast you make an unnecessary mistake.

In order to do this you need to be certain you are comfortable, can see clearly, and your CA tip is clear and ready to go, all hinges are in all slots, centered, and straight.

[sm=spinnyeyes.gif]


:D

You'll do fine,

Clay

RE: CA HINGE INSTALL HELP
 

42etus
this is were I get lost! When you say turn the wing over do you mean from elevator facing up to elevator facing down OR
top of wing facing up to bottom of wing faceing up?

RE: CA HINGE INSTALL HELP
 

CA'ing a hinge is not complicated, just as most above have stated. Look at the wing or the fuselage (if doing elevator) or right (or left) side if doing the rudder. There is a top and a bottom side or a left and a right side. Pick one.

Ok, let ME pick one. The wing, aileron, bottom to start off with.

Insert the ca hinge as previously described in the wing trailing edge. I usually put a pin in the center of the hinge so I know that equal amounts have gone into the trailling edge as has gone in the aileron itself. You can start at the extreme outside end working toward the center, or from the center to the outside edge. Push the hinge all the way in the wing trailing edge until the pin touches the trailing edge, then repeat all the way out to the other end of the wing. Now push the aileron onto the hinges starting at one end or the other, carefully pushing the aileron in until all hinges meet the pins. Then collectively, push to make sure that all the hinges are all the way in to the pins.

Carefully pull the pins out.

Open your container of CA, and if you have one, use the smallest applicator tip that you have.

Now, pick a side (top or bottom.. we've already gone through this) top or bottom. Carefully flex the aileron down so that the V enlarges as you flex the aileron down.. but be careful not to flex to far so that the hinges begin to pull out.

Put your 5 or 6 or 7 drops of CA (or however many drops are recommended in the construction manual). It will set up pretty quickly. You can wait a minute or two, but it will be ready for the other side almost right away.

Turn the wing over so that the other side (the one without the CA applied) is exposed, and carefully flex the aileron like you did above. Now put yoru 5 or 6 or 7 drops of CA (again, or however many drops are recommended by the construction manual) on this side of the hinge.

Now leave it alone for a few minutes.

Now flex the aileron several times.

You're done.

DO NOT re-apply CA. Once you have applied the CA and it wicked in to the hinge, you cannot put more. You're done. If you DO put more, you take the chance of it actually weakening the hinge joint and take the chance of it all coming apart at the worst possible moment.. while flying.

It's really easy.

If you wish, go to your local hobby store and pick up a length of balsa aileron stock and a length of 1/2" x 1/2" x 3' balsa strip, cut both into 2" lengths, and practice a few times. Put two hinges on each trying to get the closest possible gap and see for yourself how strong this bond becomes, and how easy it actually is.

CGr.

RE: CA HINGE INSTALL HELP
 

dont use kicker on CA hinges. The hinges are treated with a chemical to SLOW the curing of the CA, allowing the CA to wick deaper into the wood.

RE: CA HINGE INSTALL HELP
 

yes you can do without the kicker as well.
i just dont like to apply CA through the 1/8 drilled hole into the TE, it makes the CA harden the hinge and then it takes me hours to soften the hinges.

RE: CA HINGE INSTALL HELP
 

I rest my case .....

RE: CA HINGE INSTALL HELP
 

It's a very good thing to be clear on this and I think you're correct in being certain - once you have hit the hinges with CA they are done. No take-backs.

So here's another play-by-play (assuming you've followed MinnFlyer's procedures).

This will be for an aileron on one side of the wing with four hinges - matters not a wit whether the wing is upside down or right side up or which aileron.

Get your CA (I like to pre-load mine in one of Dave Brown's dispenser bottles with a narrowed tip), calming music, a bottle of CA debonder with the top on but lose if you have it, pull the T-pins that have assured you have the hinges evenly placed.

I set my wing or wing half in a padded cradle; one I would use to support a fuselage. Now - push the aileron with your "off" hand in about the middle of the strip (DO NOT HOLD IT WITH YOUR FINGERS UNDER A HINGE) up snug against the wing and flex it to the maximum deflection you desire - or approximately so - downward from your current viewpoint. Drip six drops into the center of the OUTBOARD hinge. Move to the next one and repeat (no flexing yet, hand on the aileron still unmoving yet firmly pressing to snug the assembly). Repeat, repeat. You've now hit all four hinges with six drops, the first hinge has been settling 30 seconds or so. Now, flip the wing over.

Flex the aileron, just once, downward (opposite direction of the propr downward push from the wing's point of view) and hit the INBOARD hinge with six drops. (See the devious cleverness here - this is the hinge that was hit the first time in the first pass and so, in the large scheme, all hinges will "rest" for about the same time - 40 seconds or more - for the CA to be absorbed. Six, drops, move, six drops, move. Done.

Take this opportunity to see if any CA is on the covering and wipe it off with CA debonder on a paper towel (or acetone). If you catch it on the covering you can usually kill it before it has set. Now, take a deep breath and flex the aileron gently but to the full extremes about six times. Do not be alarmed if there is some crackling.

Now for the heart-stopping part. Wait a couple hours. Grab a(nother) beer, down it, and tug on the aileron. It should support the weight of the wing. Better to find out now than have it come unattached at 200 feet.

RE: CA HINGE INSTALL HELP
 

its not as complicated as we make it sounds like, including you.

do what minnflyer suggested in his tutorial.

and I always make a "dry" run to practice everything without the glue (closed bottle), the "wet" run comes after i feel confident and everything is in place.

RE: CA HINGE INSTALL HELP
 

Charley - Thanks for taking the time to go into detail on this subject. Its the details that us beginners are looking for and although most of the help on here is solid and proven in the field, sometimes the experts leave out the details that may lead to failures. I bought this SSE as a fourth plane and the good reviews its had, but also because it would give me some experience in hinge installation. I feel confident now that I'v gotten some good help from all of you. Thanks ......

RE: CA HINGE INSTALL HELP
 

It really helps to use tips on your thin CA, like these.

http://www3.towerhobbies.com/cgi-bin...&I=LXL490&P=ML

Allows you to get the CA right where you want it.
Paul

RE: CA HINGE INSTALL HELP
 

Yeah, those tips are great. You can get right down to the hinge and apply the CA where you want it to be and not all over the covering, or on the floor like I do all the time..[>:] You don't realize it's there until it sets up in a lump and you see it there on the floor.

Once you work all this out, you will develop your "own style" and do what you feel is best. We've tried to point out the few issues that may come up during this process, and the pitfalls we've probably all have run into with our hinges. I did double coat the hinge with CA and it caused probems about a month or so later when the surface started to get loose on me. I ended up cutting both ailerons away from the wing and re-installing the CA hinges. This, of course, was after I got the advice from a friend.

You have the benefit of hearing it from us, those that have made the mistakes, so you don't have to make the same ones we did. That's not to say you won't make mistakes, but those that you do make will be all yours!! :D

Enjoy the hobby, and don't make a major project of installing hinges. Once you've done them, and done them right, you will see that all this was worth while and not really rocket science.

CGr.

RE: CA HINGE INSTALL HELP
 

afternoon CG.

Nice today 56* and muddddddddd.. suppose to have winds of 40 to 60 tomorrow. Did you fly that diablo yet.

RE: CA HINGE INSTALL HELP
 

Hi Irish.

Nope. It's in the car, though. I went to the field on Sunday, was warm.. so it was muddy. But it was also windy.. even more wind than I would fly my glow so no electric flying that day.

I'm off tomorrow and if we don't get the rain they promised, well, I'll be out there giving it the old college try!!

CGr.

RE: CA HINGE INSTALL HELP
 

Just remember to throw it like you are in left field. If we get the wind they are saying, we will have to button down the hatches. I think we have hatches. If your diablo flys good then I am going to get one. The ones at our club have been modified so I never seen them in the original configuration.

Hummm I think it is "batten down the hatches" Thats what happens where you are a city boy

RE: CA HINGE INSTALL HELP
 

I did my first set of hinges when I was assembling my 4*60, and was a bit intimidated by it, mostly because it was the first time having done them. After reading through some of the instructional information here and other places, and following them to the letter, it turned out to be no big deal. As you said, it's not rocket science.

I felt the same way the first time I had to do a covering repair. It's not the most beautiful job, but it's OK. :eek:

It's amazing the amount of information one can find here, and on other similar boards, and the folks here are more than willing to explain things to first timers. It's been a huge help for me.

RE: CA HINGE INSTALL HELP
 

Batten down the hatches... jeez.. :D I learned that in CG Boot camp!!! :D Actually, I went through Boot Camp in the Navy then turned coat and went in the CG [X(] .

RE: CA HINGE INSTALL HELP
 

SIG recomends NOT flexing the hinge until its well set due to the CA retardent.

RE: CA HINGE INSTALL HELP
 

Well, it can't be me, just ask my wife :D

Your method has its merit, but you DO want to do this as quickly as possible. Which I why we usually say, "4 or 5 drops of CA"

Obviously (Or maybe not so obvious to some people) if the CA is running all over the wing, you're using too much. But if all is right with the hinge, the slot and the wood, the hinge should easily soak up several drops.

But you have to remember, when dealing with the masses, you have to take into account that not everyone reading an article will be as astute as you are. So generalizations are usually necessary for the "Rest" of the people.