JoeAirPort

My Feedback: (41)

My PAU 30% Edge has been punished ruthlessly for the past three years and the left inside aileron hinge is coming loose. It's actually loose inside the control surface. Ideas to fix this? I'm thinking of drilling a small irrigation hole and injecting thin or med CA. Then plugging with a tooth pic. Anybody ideas that have lasted a few seasons? What glue would fix this best? I used Pacer hinge glue on this one. All the other hinges are solid. I must have skimped on glue (or too many rolling harriers).

Thanks

Tired Old Man

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You try the irrigatin method using an expandable urethane glue. Protect the hunge joint from adhesive entry. I've done this a few times with various levels of success.

JoeAirPort

My Feedback: (41)

That's a good idea. I have yet to do Urathane glue on hinge points. It's always been epoxy or Pacer hinge glue.

I'm leary of CA even though it will flow the best. It tends to dry brittle and could just loosen up again.

Edit: I'm wondering if thinned 30 min Zpoxy would work too? It would flow. I think that nothing will surround it 100% with new glue but hopefully strong enough to last another season...or two.

Tired Old Man

My Feedback: (1)

The problem with using thinner (less viscous) adhesives with this type of repair is that you are dependant on their ability to flow and remain in the required areas. Then again, that's the problem with less viscous adhesives from the beginning. They don't always remain where they are needed unless there is something behind them preventing an escaping flow. Sort of like filling a bucket. If it has a hole in the bottom it all flows away from the container. That's the big benefit of the urethanes. Although they also will flow away if the avenue exists, their increased viscousity and expansion rate tremendously assists in keeping the adhesive where it needs to be.

Steve

My Feedback: (54)

If you choose to repace all the hinges, I've found that cutting the nuckle and removing the surface, then use a soldering iron to melt out the old hinge leavse a perfect hole. Then use a 3/16 drill bit to clean up the hole and re-hinge.

JoeAirPort

My Feedback: (41)

Replacing them all is the better thing to do but I'm going to try the easier route. That's a pretty cool idea of removing them though. Other people take a sharpened brass tube and cut them out.

propchief

My Feedback: (65)

Joe,
I agree with drilling a hole to the hinge and using gorrilla (or other) urethane glue. That stuff will expand and find its way into the gaps. Used the some method you are describing with that profile. Just drill the hole drop in the glue, and then cover the hole with some wax paper and clamp so it can't back out. I've yet to have a hinge come loose with these glues. Also, I've used it to fix some profile landing gear areas and it held under the abuse I put it thru ... lots of abuse!

greyhound man

My Feedback: (5)

Could you just drill through the hinge and pin it in place?

JoeAirPort

My Feedback: (41)

I could pin it but the hinge point is a little small to nail blind. Also there's so much slop in the hinge hole that it needs to be filled up. The urathane glue is looking like the best solution. I'll have to get some water in there and then the urathane glue, then keep it from oozing out all over the wrong places (especially the hingle jont). I'll probably do multiple holes on the top and bottom. I'll probably put a little drop of oil on the hinge joint to keep it from sticking when the glue is all set up and dry.

altavillan

My Feedback: (1)

Make a bit of sawdust. pack some in around the hinge point, drill a small hole to the hinge point, or evan make a slightly larger hole and pack it full of sawdust. Then give er a couple drops of ca. in the new hole and it should be as good as new.
My new way of keeping glue out of the hinge is to wrap a thin strip of blenderm hinge tape around the joint before glueing. Then remove it.

Eagleburger

Wont help you much but I did some hinge points on the weekend and didnt want to put grease or any oil on a plastic part. So I just cleaned the first large part of the hole that takes the knuckle with a cotton bud. 22 hinges and they all are very smooth. Another thing I did, was to rest the part being glued knuckle down so the excess epoxy pooled around the exposed base inside the wing. Looks very strong when looking inside the wing.

nonstoprc

My Feedback: (90)

i did the same kind of repair through the use of a syringe with a needle for muscle injection. Epoxy is injected from one side of the plastic knuckle and let it flow down to the other. Properly control the depth of the needle to assure a good coverage.

JoeAirPort

My Feedback: (41)

Will epoxy flow through a needle? That sounds like a good way to get it all the way in there but I bet that needle has big holes in it (the muscle injection type).

nonstoprc

My Feedback: (90)

5-minute cure type. Yes, the size of the needle matters. I just was patient enough to push it until all in :-).

propchief

My Feedback: (65)

Joe - you can skip the wetting of the surfaces and the expansion of the glue will be reduced making it less messy. You can use masking tape next to the hinge to protect your covering and make it easier to remove any excess glue.

JoeAirPort

My Feedback: (41)

A friend of mine in the med field is bringing me an 18 gauge needle to inject the hinge hole. Either urathane or epoxy, not sure which. What's the point of using urathane of you don't use water to make it expand?

propchief

My Feedback: (65)

Joe - urethane glue will expand without water just not as much or as quickly ... I'm sure either will work using the injection method.

Nogyro

My Feedback: (10)

HAHAHAHAHAHAHA

Now on to more serious matters. (if there are any)........ I just got done doing this same repair on my PAU 36% Edge. Inside hinge on the rt aileron. I use the syringe and needle method and shot in some expandable Poly glue(Gorilla Glue) in there. I put a drop of oil on the knuckle first.... I've put 20 or so flights on it since the repair, and everything is holding up just fine. After using the Poly Glue, I still had a small pocket right at the hinge line. I mixed up just a bit of 5 minute epoxy and micro balloons and filled the hole. This made a nice hard surface right next to the knuckle joint of the hinge. Check and make sure you don't have some binding going on with the hinge. After studying mine for a bit, I found that the hinge was installed just a tad off the hinge line and was binding at full deflection. Right where it is when practicing all those rolling harriers.

JoeAirPort

My Feedback: (41)

Frank, I thought I might have some binding too. Those hinges were probably not all drilled perfectly in-line....you should see the rudder. It's almost a rudderlon. Kidding, it's not that bad. The aileron lasted 3 years so it can;t be that far off.

Nogyro

My Feedback: (10)

Joe,

I'm convinced that my problem was caused by the binding along with zero hinge line gap. IMO you've got to have just a smidgin of gap to allow for some inaccuracies in the trailing edge of the wing and the leading edge of the aileron..... It looked like they glued mine in at the factory, and never moved the control surface back and forth. It they had, the binding would have showed up.

Good luck on your repair. I chose the syringe method first. Fast and simple. Just keep and eye on it and if it becomes a problem, then cut them all out and start over. That's what I'm going to do.

I like the idea of melting the old ones out with a solder gun..... That's a new one on me.

JoeAirPort

My Feedback: (41)

Guess what I discovered upon closer inspection last night? The hinge point hole was not drilled on the hard point....that or the hard point was in the wrong position on the left wing half. Either way my hinge point was not going into hard the wood block provided. I found this out by looking at the wing with a bright light behind it. The block is clearly an inch or two to the outside of the wing. I looked at the rest of them and some are very close to missing the hard points....but there are in them.

I did not drill these holes, they came pre-drilled from the ARF MFG.

There isn't much space to get a needle in the hinge. I tried to fish some very small music wire and it had to be jammed in to even go in a little bit. Drill baby drill !!

karmann34

My Feedback: (5)

Hey Joe- If you are going to inject the epoxy with a needle, you could mix in some micro balloons. If you find that the mixture is too think for the needle, make a few passes over the syringe with your heat gun and it'll turn it into water and let if flow nicely. I'd use at least 15 or 30 minute epoxy, and when it sets up, will be just like you want.

JoeAirPort

My Feedback: (41)

DUDE !! Man this is axactly why I post these things. I got so many great ideas here. The heat gun to get it to thin out is an AWESOME idea.

Thanks, seriously.

karmann34

My Feedback: (5)

Yeah, cool how that works sometimes.

I'm lucky, I hang out with guys that beat up more planes than just about anyone.

JoeAirPort

My Feedback: (41)

Yeah you hang around the right crowd for sure.

I was just at the hardware store before I read your post. They had two injection needle glue systems there. One was like an elephant needle, a 1/16 or so thick. Then they had a really thin one that only CA would flow through. With your idea I could use the thin one and heat the Epoxy. Then I don't have to drill these huge holes along the hinge point, possibly damaging it, in addition to removing preciously needed wood from the area.