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Building Tips and technical articles. => Paint and finishing => Topic started by: Avaiojet on October 18, 2011, 09:38:44 AM
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I've painted many models. CL with only a brush, (I was a kid), plenty of RC models using the best of spray equipment. In all cases the control surfaces were already in place permanently.
I see that some prefer to paint their control surfaces removed, and they are put in place after paint.
My interest is advantages and disadvantages? Hinges stay in place? Slow Epoxy used? Preferred hinge?
What's your view and what do you do?
Thanks,
CB
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Hi.
I cannot think of any advantages in painting a plane with control surfaces assembled. It's more difficult to control how the paint goes into certain areas (hinge gaps, for example), and there is allways a risk to stiffen the control mechanics. And, if you like to sand & buff your plane after painting, the hinge gaps etc. are pain in ass to make nice.
Besides, smaller parts are easier to handle. L
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I inspected Paul Walker's Impact at the Fireball's Spring Tuneup this year. All of his surfaces use barrel-type hinges, with long music wire pins. Combine that with access hatches or plug-in elevator and flap horns, and that means that you can fit everything up when it's in bare wood, disassemble, get the paint perfect, then reassemble. It also means that if you need to take a surface off for maintenance or crash repair -- zip! it's off.
I'm not sure what the best time to glue the hinges in would be -- probably either at the bare wood stage, or about 1/2-way through priming, to give you a least-frustration opportunity to fix up any appearance-destroying boo-boos in the hinge installation.
I'm no Paul Walker, but my next plane is going to have long music wire pins holding the hinges together...
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I'm no Paul Walker, but my next plane is going to have long music wire pins holding the hinges together...
Interesting,
I'd like to see a visual of this? Any photos here or there?
CB
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I'd like to see a visual of this? Any photos here or there?
For how nice it looks, or for how it's done? You have to get your nose pretty close to the plane to see it at all. Basically you bend the end of the wire into a square "U" shape, then thread the wire through all the hinges, to replace the individual pins that would otherwise be in there.
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What material (and size) is suitable for the "hinges", or tubular parts? Or is some commercial hinge about right?
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For how nice it looks, or for how it's done?
Nice? I haven't seen it yet. How it's done? Absolutely.
I've used Kleet hinges that hold a wire with a 90 degree bend. Not rocket science there.
Just a guess, but placing these hinges close then use only one long wire to reach first hinge to last hinge?
How do you get the wire in place?
Photos?
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Paint first, then assemble.
No more Kletts, so I use Dubro Heavy Duty 1/4 scale hinges (cat#257), remove the cotter pins, replace with a single long hinge wire .047". I detail every hinge to get rid of the flashing click they seem to have right at neutral. I trim a little sliver off the length of the 2 inside barrels of each hinge. Every hinge must swing free of it's own weight before it goes in the plane. I install hinges after painting is complete. I use a 25 or 26 guage hypo to put glue inside the hinge pocket only, no glue on the hinge itself, result no mess. Seems they stopped making the Pacer Hinge glue so now I use the 560 Canopy glue, also good for plastic to wood. Its water soluable so if any ooze out (hardly ever) it's easy to clean up. After glue dries I do a pull test on each hinge. Flap and elevators have pockets built in to accept horns. Control surfaces are removalble.
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Nice? I haven't seen it yet. How it's done? Absolutely.
Trust me, they're nice. I used to do my RC planes like this, then got out of the habit. I need to get back in...
I've used Kleet hinges that hold a wire with a 90 degree bend. Not rocket science there.
Any pinned hinge. The ones that I've seen all have what looks like a sewing pin, either installed and pre-bent, or supplied with the hinge. Set those aside (or take them out). Then find the size of music wire that fits best through the hole. Put a bluntsh point on the end -- enough to ease it into the hinge, but not enough to hurt if you bump it.
Just a guess, but placing these hinges close then use only one long wire to reach first hinge to last hinge?
Use your normal number of hinges, and a wire that reaches from the outer edge of the surface to at least an inch inside the inner hinge, or the center of the aircraft. There's no real reason not to have the wire extend the entire width of an elevator, if it works out.
How do you get the wire in place?
Bend the surface to its full deflection, thread in the hinge pin from hinge to hinge. You may need to "coach" it a bit with tweezers or needle nose pliers, but with the surface deflected you should be able to get in there OK. The way I retained the pin was to just stick the end of the "U" bent section into the balsa of the surface -- it looks like that's what Paul Walker does, too, but I couldn't say for sure.
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Allen,
Doesn't the wingtip faring get in the way of putting the wire in?
Thanks for the info. Got photos?
I'll be finishing up a project and do have to make a decision on the hinge configuration.
Whatever information I can gather will be helpful with this decision.
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Flap and elevator, I leave a gap between the surfaces just big enough for the continuous pin wire. Bend a "U" in the end about .75 each way, push into balsa and put a little clear drying glue on bottom of wire.
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Allen,
Doesn't the wingtip faring get in the way of putting the wire in?
SV-11 is an example where flaps are not full span, with fixed sections at the tips.
So before I glued on the fixed tabs, I cut a slot and put a plastic tube in the fixed tab section so I could slide hinge wire thru it when installing flap.
Plastic tube has to be in line with the hinge barrels.
No comments about the finish on this one.
ARC's are not a serious plane for me, so the finish is just utilitarian.
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Allan...thanks for the tip...I haven't used the long wire yet but I'm about to put together an ARF SV-11 and I think
I'll do it your way.
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I got it!
I never considered the wire doing through the wing tip then being bent.
You only bend one end, correct?
Is this your only method?
I think both models look nice. Could you provide information about the covering and finish?
Did you know that actual aircraft, some of the 30's, used a method quite similar to what you gents are using?
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You only bend one end, correct?
Is this your only method?
I think both models look nice. Could you provide information about the covering and finish?
Yes only the outboard end is bent.
Yes my only method.
Finishes on both are transparent, covering is Polyspan.
I basically followed Pete Petterson's method as he outlined in Stunt News article, Jan 2009.
Clear dope tinted with House Of Kolor Kandy Koncentrates. 10oz dope, 10oz thinner, 1/2oz tint
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Allen,
Thanks, and I see your on line.
Polyspan? I must learn about it. Colors available?
Your hing line detail. The wing tip faring has what looks like a thin layer of covering, 1/64" or 1/32" thick.
Nicly made and attached to the faring. Spacer? To close the gap or just a finishing touch?
Also it appears as though you have a darker color on the flap side of the TE. Applied color?
Thanka Allen, you do good work.
CB
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Polyspan is available in colors other than white, but a number of people reading this are raising their eyebrows and saying "oh, really?", because as near as I can tell it's mostly the free flight community in the US is aware of the other colors.
At any rate, the technique he's talking about is to use white Polyspan, then use clear tinted dope for color.
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OK,
So the builder started out with white and just tinted the material with translucent no opaque paint. Correct?
I've had, and expect to have good results with silk. Comes in many colors if you elect to have some of it showing. Easy, just simply clear the stuff.
Polyspan? Why not just use a color for starters?
Polyspan is applied same way as silk?
The models do look good.
CB
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OK,
So the builder started out with white and just tinted the material with translucent no opaque paint. Correct?
I've had, and expect to have good results with silk. Comes in many colors if you elect to have some of it showing. Easy, just simply clear the stuff.
Polyspan? Why not just use a color for starters?
Polyspan is applied same way as silk?
The models do look good.
I think there may be at least two different products called "Polyspan" -- the stuff that I've gotten through Hobby Lobby is denser, and the colored stuff is definitely toward the opaque end of translucent. The stuff that I've gotten from control line channels is less opaque than silkspan, and that's what I've seen on Pete's planes.
And yes, the the House of Kolor tints are just that -- tints, like food coloring in water.
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I only know of one Polyspan and it comes in white only. You can get it from CLC, Tom Morris, Peck Polymers.
Its a heat shrikable polyester fiber.
I apply it dry with dope same as you would silkspan and then heat shrink it.
On the red plane (SV-11), I covered the flap with cf veil, thats why it darker.
Spacer ? Not sure what you are talking about.
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On the red plane (SV-11), I covered the flap with cf veil, thats why it darker.
Spacer ? Not sure what you are talking about.
Allen,
I like the tint idea. Much can be done with that. Just about any color?
What is cf Veil? There's a tiny piece of material, applied to the tip faring at the end of your flap.
Do you have photos of your other CL builds?
Thanks,
Charles
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Tint available in many colors. Google "HOK Kandy Koncentrate" Other brands available.
End of flap and inside edge of tip tab are capped with 1/64 ply to keep them crisp. I painted the hinge line gap black.
cf veil = .2oz/yd carbon fibre tissue used as a covering to add torsional rigidity to flap
Go to "BrotherHood of the Ring" website, in my album section under "perretar" for full pictures of the yellow plane above (RMD-3) and my Chevelle.
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Allen,
I'll go there, I'm a member of that site.
cf veil = .2oz/yd carbon fibre tissue used as a covering to add torsional rigidity to flap
Where do I get this product?
What do you do around the area where the control wire goes into the flap?
CB
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Allen,
I'll go there, I'm a member of that site.
Where do I get this product?
What do you do around the area where the control wire goes into the flap?
CB
Scroll down the page to Carbon Fiber tissue
http://www.acp-composites.com/home.php?printable=Y&cat=251 (http://www.acp-composites.com/home.php?printable=Y&cat=251)
The most common way flap horns are attached to day is by capping the inboard edge of the FLAP / Elevator with a 1/32 ply followed by a 1/8th or 3/32 ply piece cut with a slot for the horn wire followed by another 1/32 piece to cap it off. The horn wire fits into the slot of the 1/8th or 3/32 slotted ply.
Some use lucky boxes just search the forum for Lucky Box.
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As far as the original part of when to permanently install control surfaces, I always have every thing finished then I glue in the hinges.
I also have made a few different size "sanding sticks" to allow the barrel of the hinge to sink into the control surface. Simple tool made from ply with a scrap piece on the back to grip and the face holds a strip of ply the width of the hinge barrel and is the same "thickness" (depth off the backing plate).
Big Bear
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On the yellow RMD-3 I made the horn pockets out of spruce sticks seperately and then glued to inboard edge of flap. The slot is 1/8 high, 1/4 wide,
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Look Allen,
Just send me a few of those. :-)
OK, The "pocket" is separate and you don't drill the flap.
Glue the "pocket" to the end of the flap, then sand flush. Trust the glue?
Finish with a layer of silk or Polyspan, or 2oz CF Veil.
Am I getting it?
Allen,
PM me for my address.