hinges frozen

[Al Williams]

How do I free up doped cloth hinges???  The plane is a brodak Yak. The wing has silk span with two coats of clear dope and the ailerons are installed with cloth hinges.  In doping the silkspan and doping the ailerons the dope got on the hinges and now the ailerons will not move.  I still have to paint the plane with colored dope which I planed on doing by spraying with an air brush.  This again will get the dope on the hinges. The elevator has sewn hinges which do not seem to have a problem but probably will when color is sprayed.
Thanks

[Dave_Trible]

If they are really bad you may have to apply some acetone and just pull them off and replace them.  Then when new ones are put on be careful not to get much dope down in the hinge line when you dope them.  A little will wick down anyway which is needed to keep engine oil from rotting them out right away.  You need to dope with a brush-spraying is near impossible to stop getting too much.  In any case the controls will be a little stiff to begin with and will loosen with a little flying.  This is a prime reason airplanes didn't last for more than a few years in the old days.  Oil soak would get to the hinges and it was often too much work to re-do the whole thing. 

Dave

[pmackenzie]

Hmm, seems like a lot of work for something that does not hold up!
Is there a better method of doing these sort of  slab elevators, 1/8" thick like some of the kits use?

Tape, or sewn hinges perhaps?

[944_Jim]

I can't help with stuck-fast cloth hinges, but I do like sewn hinges. Another hinging method that produces absolutely floppy hinges in smaller models is floppy disk hinges. I don't think  I'd use this method on anything above 1/2A.
Slit elevator and stabilizor with a razor, insert 1/4" wide by 1/2" (5/8" is better) long pieces of floppy disk material into the slits. Secure material in place with CA glue. If you carefully drill a hole or two per slit into each slit, the the CA will wick to the bottom of each and hold the material securely. Scuff the material a bit before inserting. This is basically home-brew mylar hinges.
The stab and elevator must be bevelled to prevent binding in the hinge line. It is easiest to make the slits before working the bevels. I use a surgical scalpal so I can go deep in the balsa. Alternatively, make the stab and elevator from two layers...that is, laminate them with the material trapped between laminations.

[EddyR]

Send a picture. Maybe the entire flap is filled with dope not just the hinge

[Avaiojet]

How do I free up doped cloth hinges???  The plane is a brodak Yak. The wing has silk span with two coats of clear dope and the ailerons are installed with cloth hinges.  In doping the silkspan and doping the ailerons the dope got on the hinges and now the ailerons will not move.  I still have to paint the plane with colored dope which I planed on doing by spraying with an air brush.  This again will get the dope on the hinges. The elevator has sewn hinges which do not seem to have a problem but probably will when color is sprayed.
Thanks

IMHO, and a due respect, I think you've made a few mistakes from the get go. They have nylon hinges with pins which you insert. You can see these all over the Forum and how to work with them.

Clear dope on balsa is OK, but I generally apply a few coats before I attach any control surface, In my case, I even do the covering and primer before attaching.

Some guys even "finish paint" these surfaces and connect the hinges afterwards using Epoxy.

Cloth hinges or stitched hinges I would never consider, but that's me. "to each their own."  If the kit thickness of the tail feathers are 1/8, you could remake them to 3/16" allowing a bit more forgiveness to insert a nylon hinge.

I used nylon hinges on my kit built Flight Streak with little difficulty. 1'8" balsa.

I wouldn't cut the cloth hinges and replace them with cloth hinges. I'd use a nylon pinned hinge.

I've never had to "free up" doped hinges before or a control surface stuck with dope, but I'm guessing dope thinner should do the trick? Possibly.

Nylon hinges weren't available when the earth was formed. CL products have come a long way.

Good luck.

Charles

[Mark wood]

Hmm, seems like a lot of work for something that does not hold up!
Is there a better method of doing these sort of  slab elevators, 1/8" thick like some of the kits use?

Tape, or sewn hinges perhaps?

 Like Jim, on surfaces this thin I prefer to use laced hinges. There's lot's of ways people do them. Me, I do two or three locations on each side. For a half A One hole 3/16 from the hinge line on the fixed side and on the moving sides. I use monofilament the size of whatever is on the bench, usually 8 pound. Begin with a simple overhand knot pulled in to the hole and figure eight through the hinge line 4 four times and finish on the opposite side with an overhand knot pulled in to the hole. A drip of thick CA + activator in each hole will prevent the hinge from moving. On larger models I'll do the same thing but add a hole at each location. Some people do a baseball stich across the entire TE. I've never found that much to be necessary but if'n you like the way it looks then by all means do it that way. Laced hinges are far better than cloth hinges IMO.

[Leonard Bourel]

I know this may sound crazy but I have used cloth hinges on lots of planes over my 45 years of controli line modeling and many times I have got the hinges stuck with glue dope etc What I do is just gently grab the flaps where the horn enters the flap and near the tip and maybe get a helper to do the other flap at the same time  gently bend them both directions slowly at first and after a few cycles up and down they will begin to free up I have never not been able to salvage them Good luck

[Avaiojet]

Like Jim, on surfaces this thin I prefer to use laced hinges. There's lot's of ways people do them. Me, I do two or three locations on each side. For a half A One hole 3/16 from the hinge line on the fixed side and on the moving sides. I use monofilament the size of whatever is on the bench, usually 8 pound. Begin with a simple overhand knot pulled in to the hole and figure eight through the hinge line 4 four times and finish on the opposite side with an overhand knot pulled in to the hole. A drip of thick CA + activator in each hole will prevent the hinge from moving. On larger models I'll do the same thing but add a hole at each location. Some people do a baseball stich across the entire TE. I've never found that much to be necessary but if'n you like the way it looks then by all means do it that way. Laced hinges are far better than cloth hinges IMO.

Mark,

Could you put up a photo or two of your stitched hinges? Especially you're larger models.

Maybe I should try it.

Charles

[Mark wood]

Mark,

Could you put up a photo or two of your stitched hinges? Especially you're larger models.

Maybe I should try it.

Charles

Well, they aren't the purdiest things on the planet but they are reliable. I don't think I have ever used anything different on speed or racing models. I don't have any older large models and all of my recent models have used Klet style hinges with pins. The reason being is I can pull the pins and use one long wire which fills the gap. The red one is a trainer and the yellow one is a formula 40. If you're after super nice looking they may not be for you. If you're after good, easy and reliable, definitely an option better than cloth. In fact, slicing through cloth hinges and replacing with laced hinges is one of the ways we kept those models flying.

[Avaiojet]

Well, they aren't the purdiest things on the planet but they are reliable. I don't think I have ever used anything different on speed or racing models. I don't have any older large models and all of my recent models have used Klet style hinges with pins. The reason being is I can pull the pins and use one long wire which fills the gap. The red one is a trainer and the yellow one is a formula 40. If you're after super nice looking they may not be for you. If you're after good, easy and reliable, definitely an option better than cloth. In fact, slicing through cloth hinges and replacing with laced hinges is one of the ways we kept those models flying.

Mark,

That's not what I expected. You do really nice clean work and it's not overdone. Good for you! 

Charles

[John Park]

Recently, I've built several small models with 1/8" sheet tail surfaces, and employed sewn hinges using the Spectra line I use for control lines.  This gives nice free hinges that should be durable. I used to use Terylene (Dacron) thread, but it tended to stretch and produce a rather gappy hinge-line.  I gave up using tape hinges many years ago, as they always failed after a couple of seasons, if not sooner, and had to be replaced by sewn hinges.  A neighbour once gave me some of the Mylar sheet (about .004" thick, as I recall) that he used for R/C hinges, but I didn't find it free enough for C/L use, even on larger models.
One final thought: I was worried that Spectra, being so thin and tough, might eventually cut its way through 1/8" balsa, so my most recent small model has the tailplane and elevators capped with 1/8"  sq. spruce, suitably radiused, just to be on the safe side.

[Mike Griffin]

Maybe I am really confused here or don't understand the problem but I use nothing but cloth dacron hinges for flaps and elevators and I dope them down to adhere to both the stationary and moveable pieces.  When they dry I just grab the flap or elevator and move them back and forth to break them free and there is very little resistance to this and the parts move freely.   I guess I do not understand the problem.

Mike

[Dan McEntee]

How do I free up doped cloth hinges???  The plane is a brodak Yak. The wing has silk span with two coats of clear dope and the ailerons are installed with cloth hinges.  In doping the silkspan and doping the ailerons the dope got on the hinges and now the ailerons will not move.  I still have to paint the plane with colored dope which I planed on doing by spraying with an air brush.  This again will get the dope on the hinges. The elevator has sewn hinges which do not seem to have a problem but probably will when color is sprayed.
Thanks

     Al;
    If you can post some photos, that may help. You need to make sure you have the leading edge of the flap shaped properly. If not. and you have the hinges laid in nice and tight, you might not get them to loosen up. Like some of the others, I have never had them lock up completely but got stiff, then just moving them by hand broke them free and they got better with time.
   HAPPY NEW YEAR!!
  Dan McEntee

[Peter in Fairfax, VA]

I'm sure it is obvious, but sewn hinges can be added after painting.  Sewn hinges are also easy to replace.  I used them a lot on combat planes, such as Bear Models Sidewinder.

I like pinned flat nylon hinges a lot, (Klett, etc.) especially when they are secured by being pinned in place on both surface with a toothpick.  I'm curious how you do with your 1/8" surfaces, as I would like to try Klett on some trainers I am building  The tip to cut the square part into a triangle sounds good.  I plan to experiment on a mock-up before constructing the whole plane.

thanks for sharing,

Peter

 

[Mark wood]

I'm sure it is obvious, but sewn hinges can be added after painting.  Sewn hinges are also easy to replace.  I used them a lot on combat planes, such as Bear Models Sidewinder.

I like pinned flat nylon hinges a lot, (Klett, etc.) especially when they are secured by being pinned in place on both surface with a toothpick.  I'm curious how you do with your 1/8" surfaces, as I would like to try Klett on some trainers I am building  The tip to cut the square part into a triangle sounds good.  I plan to experiment on a mock-up before constructing the whole plane.

thanks for sharing,

Peter

1/8" isn't hard, it just takes careful slot cutting and clearing. I actually like the Great Planes hinges which are no longer available but, I call of the hinge style Klet hinges as that how we knew them back in the day. I have used a bunch of different tools over the years and recently found these guys. They're a bit pricey but worth it.

http://aerobroach.com/

[Dave Hull]

Another example of a sewn hinge. This one actually is painted. It is a clearcoat and ready to fly. A few comments if you decide to try them:

--Use Spectra line as it performs better than anything else I have seen or tried. (eg. not Dacron, not kevlar, not monofilament, not dental floss, not....)
--Use a hardwood spar so that you can cinch down the hinge tight and not have it pull thru a balsa surface
--For a thin surface (maybe up to 3/16") you don't need to bevel either side. Make one and you will see why this is so.
--Secure the knot with thin CyA. If you can manage to tie the knot so that it is over a hole on the under surface, you can push the knot into the hole and make things smoother
--Install the surfaces after all the painting is done. You can do it the other way around, but sometimes getting paint on the hinge and especially into the gap looks much worse than otherwise

Dave

[Al Williams]

Thanks for all of the replies.  To bring to a conclusion I put acetone on the hinge joints and they freed right up.  From now on I will use sewn hinges and they look cool.

[Serge_Krauss]

Late as usual, but count me in on those who see no problem with - carefully applied - cloth hinges. If applied with dope, the above suggestions should work, although I don't see why they would not move at all, unless you have some wood-to-wood adhesion.

For future reference though, I think that aliphatic resin or (better) simply "Elmer's" is the way to go. After doping the sanded, rounded or beveled edges, I use Water-soluble glue as the best start, with ONLY the actual hinge contact area at the flap or elevator surface coated. I pre-coat with thinned Elmer's, using a small brush along the entire hinge line, but only under where actual cloth hinges rest. Then I glue each hinge piece (top and bottom, first picture) along one edge (wing or stab). After preparing the moveable piece the same way, I splay the hinges and hold the flap or elevator between them and glue first the root and then the tip pieces to align them. The rest follow. When painting, papering, or glassing, whether with dope or epoxy, I mask off the hinge line and do not BRUSH enough along the edge to run into the hinges. The rest can be sprayed - or whatever. I have been veneering balsa/glass over the stabs and tapering them toward the hinge. This may or may not help aerodynamically, but with a recess, they shield the hinges from engine spray.

The control surfaces don't fall freely as pinned hinges allow, but they are free enough for me. Just a couple of pictures. You can see where patches have been pre-coated with white glue.

[pmackenzie]

Late as usual, but count me in on those who see no problem with - carefully applied - cloth hinges. If applied with dope, the above suggestions should work, although I don't see why they would not move at all, unless you have some wood-to-wood adhesion.

For future reference though, I think that aliphatic resin or (better) simply "Elmer's" is the way to go. After doping the sanded, rounded or beveled edges, I use Water-soluble glue as the best start, with ONLY the actual hinge contact area at the flap or elevator surface coated. I pre-coat with thinned Elmer's, using a small brush along the entire hinge line, but only under where actual cloth hinges rest. Then I glue each hinge piece (top and bottom, first picture) along one edge (wing or stab). After preparing the moveable piece the same way, I splay the hinges and hold the flap or elevator between them and glue first the root and then the tip pieces to align them. The rest follow. When painting, papering, or glassing, whether with dope or epoxy, I mask off the hinge line and do not BRUSH enough along the edge to run into the hinges. The rest can be sprayed - or whatever. I have been veneering balsa/glass over the stabs and tapering them toward the hinge. This may or may not help aerodynamically, but with a recess, they shield the hinges from engine spray.

The control surfaces don't fall freely as pinned hinges allow, but they are free enough for me. Just a couple of pictures. You can see where patches have been pre-coated with white glue.

Good write-up

What material are you using for the hinges?

It also looks like you are using them full span, on some plans I only see them used in a few places.
Or perhaps the draftsman got lazy, and only drew a few?

[Dan McEntee]

   An advantage to making the hinges full span of the flaps, no need to seal the hinges. I think it was an interview with Bill Werwage where he explained that he used cloth hinges full span on his original Area models. He had built a replica years later but used pin hinges instead, and had some issues trimming the model. Then it occurred to him that the hinge line was open and after sealing them with tape, then the model behaved like his original. I think that if you make them full span you can make them just a bit smaller and they may be easier to complete and finish off.
  Type at you later,
   Dan McEntee

[Serge_Krauss]

Good write-up

What material are you using for the hinges?

It also looks like you are using them full span, on some plans I only see them used in a few places.
Or perhaps the draftsman got lazy, and only drew a few?

I think this was taffeta - probably whatever I got from Brodak or Tom Morris, but I've bought a sheet of fabric from JoAnn fabrics since then.. Yes, as Dan says, I used them full span to seal the hinge line and to minimize flexing.

[dale gleason]

When installing (sewing in hinges), always start threading on the inside hole and then sewing toward the outside. and. similarly. do the inside hinges first and then work outwards. 

That's a lot easier, quicker, and neater.

dg

[Mike Griffin]

I struggled with pinned plastic hinges for a long time until I spent a few days with Tom Morris in his shop years ago.  Tom used nothing but Dacron hinges and applied them full span on flaps and elevators.  He doped them down.  They were the most flexible of any hinges I had ever seen.  Ever since that day, I did the same and never looked back.  He cut his hinges for flaps, 2" long and 1" wide.  Elevator hinges he cut 1" x 1".  All of the flaps and elevators i attached this way would collapse under their own weight when you held them in a neutral position and released them.  I know a lot of people that were hinge snobs and would turn their nose up at cloth hinges but I figured Tom knew what he was doing.  I learned a long time ago in business if you wanted to be successful, observe successful people and copy what they do.  I think the same principle applies in building model planes.

Mike

[pmackenzie]

I just looked at the never-flown Tom Morris built Cavalier I have - cloth hinges Lots of paint on them as well.

(Got it second hand. Never flown because it has some other issues that I have not figured out how to deal with)

[Les Akre]

Lately I've been using an Iron-On Gapless Hinge that was manufactured by GRANITE STATE R/C PRODUCTS, INC. Each package has hinge material that is 46 inches long. I decided to test the application on the stab of my first Clown Racer. I was impressed with how easy the installation was. When ironed on, they produce a continuous "no-gap" hinge. I cya'd the edges on mine just to be sure they wouldn't come loose, then glassed over the stab/elevator including the hinge flap almost up to the hinge edge on each side. Even after painting, the hinge area never really got stiff, and the model is now over 10yrs old and the hinge area is still fine. I've been able to find several packages over the years, and hoard them like good modelers do.

Les

[Brent Williams]

TDM (Traian) has a good method for using 1.7lb Kevlar cloth cut on a 45° for the hinges.   
Saturate the kevlar with thin CA so it can be cut with regular scissors. 
Cut a 1/2" strip of kevlar on the 45° bias of the weave, and cut into small hinge size sections. 
Make a slit in the balsa on each side of the hinge, slide the kevlar into the slots. 
Drop a bit of CA onto the hinge to wick into the balsa. 
Once cured, flex the hinges to fracture the CA. 
Thin, light, flexible and simple.  (But not removable like a pinned hinge)