Paint or covering?

I'm building a Top Flite Cessna 182, 81" wingspan, from the kit. This is
only my second plane so I'm still quite new to building. The wing is done
and the fuse is nearly done, so I need to decide between painting or
covering it soon. For those not familiar with this plane, it is completely
sheeted with 1/16" balsa on the wing and tail and 3/32" on the fuse. My
covering experience is limited to covering one 40 size trainer with
monocote, which turned out pretty good.
I've been following the thread started earlier today about prepping balsa
for paint and it seems that it is more than just sealing the balsa and then
applying the paint. Question: Is the step of applying tissue or a
lightweight cloth necessary? If so, what is the purpose, strength?, smooth
finish? or ????
My next question: If I decide to cover it with monocote, how should I prep
the balsa surface? Do I just need to clean it well, or does it need to be
sealed?, How and with what?
Last question: Can anyone tell me just what the difference is between
Ultracote, Monocote, Econocote, xyz-cote. I've asked guys at the club and
everyone seems to have a different answer.
Thanks for bearing with me here, I've got a lot of time into this plane and
I don' want to screw it up now.
TIA
Paul
Reply to
Paul in Redland
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Nearly all kits are designed with the covering adding significant strength to the airframe. Even fully sheeted surfaces are not nearly as strong uncovered. Paint over bare balsa WILL crack eventually without some supporting cloth or tissue underneath. It will also be very difficult to fill in the grain without adding a lot of unnecessary weight.
The Cessna (full scale) is an aluminum skinned plane. The models can be covered in chrome or aluminum Ultracote and trimmed with color and look great. I don't use Monokote for this because it looks too shiny and is more prone to producing bubbles when overlapping colors.
Reply to
Paul McIntosh
I don't paint, so I can't give you any advice about painting. But I can say a thing or two about polyester film.
Monokote: My favorite covering. I have tried the rest and always came back to Monokote. I have a large assortment of colors on hand, and that's what I use. The advantages are that the colors (except different shades of red other than missile red) are opaque, you can write on the balsa with ball point pen and it doesn't bleed into the monokote, you stick it down once and it stays there, it is very strong and tear proof, and it has a definite temperature range for sticking and shrinking. Disadvantages: it looks like shiny plastic instead of a real plane, but all the films do. If you use metallics sometimes they don't stick as well, and the pigment bleeds out of the edges. But who can afford metallics? The fluorescent colors fade in a matter of days, but they are as ugly as a mud fence to start with, so why use them?
Ultracote/Oracover: Good stuff that pulls around compound curves like nobody's business and is strong like Monokote. It has a lower temperature adhesive that will allow it to go straight on bare foam. Disadvantages: The adhesive isn't permanent, which means that you stick it down around the edges and then apply heat for shrinking and the edges will come undone and the whole panel will pull together in the middle. I hate that. The colors are not opaque, meaning that you can see wood grain through them, and if you have any ink on the wood it will bleed into the pigment. This isn't usually a problem, but it happened to me once or twice and I found it irritating. Some say that having adhesive that will release with heat is an advantage, but I say put it where you want it, stick it down, and it had better stay there. This is particularly bad if you use dark colors and put the plane in the sun on a hot day. I hate it when I take a pretty plane out to the field and the covering sags right off of it. Also, they used to sell a product called Ultracote Plus. I don't know if it is still available. I hated that stuff. It was sticky on one side, which meant that it stuck to itself and everything else before I could get it on the airplane. It was a really bad idea.
Other brands of cheap-o-kote: Balsa USA, Hobby Lobby, etc, have sold various brands of cheaper covering that are a real bargain for the low budget model airplane builder. However, most of these products will tear if you get a nick in the edge and won't stop tearing until you reach the opposite side. Also, if you are unfortunate enough to peel the plastic off the sticky side and have the covering fold over and touch itself, you might as well just throw the piece away because you will never get it to come apart without ripping it to shreds. And there usually isn't much of a color assortment. But these products generally pull around curves better than any of the more expensive brands. And when you stick everything down the seams disappear because the film is thinner than the more expensive brands. Also, these films usually have lower temperature adhesive that will stick on foam. I know of at least one brand, Econokote, that is NOT fuel proof. I am pretty sure that Towerkote isn't either.
If you were building combat planes with a short lifespan, I would wholeheartedly recommend the cheap stuff. But if you want to have a plane that comes out to the field every summer for 15 years you probably ought to put Monokote on it.
Reply to
Robbie and Laura Reynolds
0.6 oz glass cloth and epoxy. Lots of work and sanding but the finish (properly done) is superb.
Reply to
Tommy
Not very many modern 182's with a polished bare aluminum finish around. In fact none are that way from the factory. I think that model has fiberglass wingtips which would be difficult to cover. If using the kit color which is probably white and would match white Monokote. If so I would cover with white Monokote, then trim to match a factory trim scheme. If the wing tips need to be painted then I would use Ultracote and either Ultracote paint or a differant color paint for the wingtip. You can prep it with Balsarite if you like, but not really necessary. If you decide to paint the polyurethanes do not tend to crack, that is why they work so well on fabric. The main reason to use silkspan or tissue is to reduce the amount of primer which adds a lot of weight, it does not add significant strength. If the instructions do not say that it must have either plastic or fabric covering, or be fiberglassed before painting, then the wing is strong enough to be flown with just the bare wood, though it would soak up a lot of oil that way.
Reply to
Sport_Pilot
Hi, I usually use Balsarite on the bare balsa before covering with monocote. Balsarite will seal the wood without adding much weight. Then I sand the balsa, with fine paper, just enough to smooth it down. Balsarite, when it dries (right away), will harden any "hairy" wood, making it easy to sand.
Then I apply the covering. Here in Kansas, where you can be flying in 100 degree, 99% humidity in the morning, and 45 degrees, 18% humidity that same afternoon, covering develops wrinkles. Balsarite keeps the covering where it's supposed to be, no matter what.
I trim the covering with real, old fashioned safety razor blades, mounted in my own home-made holder. The hobby blades and paint scraper blades as sold in hardware stores/hobby shops, are just too dull to do a good job.
If you are adding trim over the film, wet the surface, lay down the trim, squeegee out the air and water with, say, a credit card or cotton cloth, and then heat it. This eliminates air bubbles if done carefully. Practice this technique a little. You can also use a small diameter sewing needle to puncture a few holes in the covering film, to help insure no air bubbles.
opinions will vary, JK
Reply to
jnkessler

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