An instruction video that teaches you how to use brown kraft package wrapping paper to laminate and strengthen foam wing cores. The result is a very light but very strong model airplane wing, without the need for any sort of spar.
Thank you. Scouring youtube for scratch building I've only seen one other paper-covering foam video. I'm glad to see such an excellent example of just doing it - You even mentioned little tidbits of info that I had bouncing around in my head, like just exactly how-much-heavier it gets. Great vid - thanx again.
What we have here is stressed skin construction which has amazing torsional strength,it is cheap to build and highly practical,I have used such panels on high wing braced monoplanes with simple stub spar joiners at the wing root,howevr butt joining and taping up with something like open weave bandage is very strong and spreads the load along the wing for strutless construction,brown paper really has its uses in foam model construction.
I'm trying to get back into RC, most of my flying was in the mid 1970's. Back then I would sheet foam wings with balsa but this looks like a much better idea. Thanks for posting the video, great job!
This has been by far an amazing video. I'm literally just getting into the hobby and have started designing my own wing, and was gonna go with foam cutting so I can control the root and tip foils. I was really worried about having to go to the trouble of trying to incorporate spars, but your video has saved me lots of hassle.
I have used thinned wood glue to adhere both brown paper and balsa skin to foam. I thinned the glue and added a little food dye so you can see that the glue is evenly spread, let it dry then use a covering iron to soften the glue to join the surfaces. I have done this on my Byron BD5J and on a scratch built wing that has been stuck 30 feet up a gum tree since 2006, and there is no sign of delamination!
Good job sir! I do have one trick that we used to do for extra strength regarding wing loading. We would put a strip of fiberglass filament shipping tape on the underside of the wing along the spar line before covering. It acted like a tendon and would keep the wing from snapping in a hard dive or turn.
yo hace treinta años por falta de monocote, usaba este metodo con el mismo papel pero en alas de extructura de balsa y quedaba bien, no era tan pesado como algunos piensan. se pegaba todo el borde exterior del ala, un centimetro apriximado con cola blanca y cuando se secaba, se mojaba el papel con la misma cola blanca rebajada con agua, al secar tensaba como un tambor,se lijaba con lija fina y se pintaba encima.En fin el metodo de aviacion antigua pero en lugar de tela se hacia con papel. buen trabajo Brian.
Excellent video, Brian. I have seen where Flite Test used a similar technique using water based acrylic to laminate some of their planes, but I believe that using the glue would provide a stronger wing. I have not tried the hot wire foam cutting technique yet but build my planes out of the Dollar Tree Foam board. I am going to try and remove the paper from the DTFB and laminating with your process and see how that turns out. I would suspect that if i used the "waterproof" type of glue it would help.
You could use waterproof glue....or use another trick shown on FliteTest.....paint the finished plane with Minwax fast dry polyurethane.....SPIRIT based.....NOT water based. It doesn't add much weight and when dry, is completely water proof. It is also an excellent base/primer for any top-coat paint you might then want to use. Seach my name as an author on FliteTest and you will find some planes painted this way. Brian.
I've used white glue sealer for epoxy for years , since the 70's I would go with vinyl acrylic either or Gorilla Glue clear( it doesn't foam up) because white glue is flexible when it dries vinyl acrylic is Superior in all Ways , if that's just plain Elmer's it is susceptible to water and solvents such as acetone
I just bought a roll of brown paper at the dollar store yesterday wondering if I could do this. Now all I have to do is learn how to cut foam wings! LOL
People who have never tried this method will think, oh! that can't be strong. They sure will be amazed at the strength of paper and glue. The glue soaks into the paper, and when dry turns into a kind of thin plywood sheet. When it's totally dry it leaves a beautiful sound as you touch it, almost a hollow feeling, I love it. It's idea for small to medium size wings and anything bigger I'd add somekind of reinforcment. I wouldn't go adding CF spars cause then it's becoming too much like hard work, which would defeat the whole purpose. This method is for the guy who wants a super fitted wingskin with great strength but doesn't want to invest too much of his time. If you really have to have a spar, I'd use strips of fiberglass wetted out, top and bottom of wing, and when dry, cover with paper......phew😩
Thanks for the excellent video Brian - still relevant after all these years! Two questions however: what "grade" - i.e weight - of Kraft paper do you use for these wings? Second - any tips on what kind of insulation foam you use? Many thanks . . .
The brown craft paper is relatively heavyweight. It was a large roll of packaging paper that I still have. Lighter paper would work just fine, the heavier paper isn't an issue weight wise. The foam is pink or purple insulation foam from big box store. I usually buy it in 4x sheets and either inch and a half or 2-in thickness.
This is a great way to cover foam wings and nice and cheep too,. But I find that you need to seriously weigh down the wings overnight as the paper shrink is seriously strong, or you may get warps in the wings Best to use water based emulsion paint first and let it drive for a couple of days and then thin coats of car aerosol arylic
I've used 60 lb brown paper with very slow laminating epoxy for a wing. I spread out the epoxy, then squeegee it in after a few minutes, then do the other side. After that, I vacuum bagged it onto the cores. That was a lot of trouble, but less trouble than using fiberglass. The result was a very tough hlg wing of about 150 grams, which was a bit over my weight budget. I stepped on the tip by accident once, and it didn't break, though I think it distorted a bit. The trailiing edge was a bit wobbly, but I'm sure I could figure out that problem. I suspect that with 40 lb paper, it would have been light enough, and adequately tough. You can get lifetime sized rolls of different weights of kraft paper from Uline. The prices aren't too high, considering how much you get. I wonder if anyone has explored gummed paper tape for use on foam model airplanes? It might be more consistent and easier, though perhaps it ought to have a finish put on the outside later. At some point, I did some testing of kraft paper/epoxy vs fiberglass/epoxy. In bending, the paper was at least as stiff, for the weight, as the fiberglass. I had to do some calculations, though, because the fiberglass was not exactly as heavy as the paper. Stiffness/weight gets higher as the material gets thicker, so it's necessary to adjust the results to reflect this. I wonder how other types of paper would do?
Thanks very much for all this information. Kraft paper is the one to go for I've heard - longer fibres make for stronger paper. Available in different weights. And Eyeball Aeronautics here on RU-vid uses newsprint - also from Uline or similar suppliers - with white glue. My requirements are: inexpensive, light, strong, quick to make. Not asking too much, eh? I plan on doing some experiments . . .
Tips: The paper comes off much easier if you mist it with a water spray. The paper should be removed from both sides, then the tape applied, then bend. The results are better. If you leave the paper on, it will NOT be waterproof and even high humidity could cause it to peel off.
I think you are missing a couple of important points. Yes, it's a lot of elmer's glue but that doesn't matter for several reasons. FIRST: the main reason for using the construction method is COST...it is dirt cheap. Insulation foam, craft paper, and white glue. The wing costs pennies. SECOND: It is incredibly strong. There is no spar and no spar needed. THIRD: the finished weight of the wing simply isn't an issue. Elmer's glue is mostly made of water and the water all goes away, leaving behind the alphatic resin only. I don't know if you watched the video to the end but I showed the weight of the bare foam and then the weight of the finished wing with glue and craft paper. I have built and flown a half dozen planes with wings built this way, including a version of the Midwest Hots that I call the Hots-e (electric hots...my own design). It has a 3 foot wing span, is fully aerobatic, flies for 6 minutes on a 1000mah pack with lots of maneuvers, or 8 to 9 minutes with very lazy flying. It penetrates the wind quite well and can fly easily in a 10 to 15 mph wind. It has a great glide. It is NOT heavy; it's flying weight is perfect. I've been flying R/C for 35 years. I have seen and flown lead sleds (not my planes but fellow club members). I know when the weight is a good match to the wing loading. The planes I've built with this wing construction method have been great fliers. The wings could be built lighter, at the cost of much more time and money, but being lighter wouldn't be better. A lighter Hots-e would be pushed around more by the wind, wouldn't penetrate the wind as well, and doesn't need any more glide than it already has.
I probably could use a little less glue, but the weight, with the glue that I used, is NOT an issue. The panels shown in the video ended up being 84 grams ( a bit less after trimming the ends and the dihedral angle. 1 ounce = 28.35 grams. Divide 84 by 28.35 and you get 2.96 ounces. The assembled wing is therefore just shy of 6 ounces and this is a 4 FOOT wing with a 7" chord (before adding ailerons). Show me any other wing that big (and that STRONG) that weighs less than 6 ounces. One of the first planes that I built with this technique is my own design, loosely based on the Midwest Hots .40. It has a 38" wing span, and measures 35" from the rear edge of the rudder up to the tip of the spinner. This plane (Hots-e) fully stuffed (except for the fligth battery) weighs 15.1 ounces. I use a 3s 1000mah zippy compact 35C battery to fly this one. The battery weighs 3 ounces, so the all up weight is 18.1 ounces. It flies like an angel. I put 3 flights on it this evening in the calm air. I loafed around on the last flight, keeping the throttle at about 40% for the entire flight. I did lazy circles and a few loops and rolls. I was airborne for 11.5 minutes before the battery was done. I would NOT want this plane to be any lighter. It is perfectly balanced all around. If it was lighter, I wouldn't penetrate the wind nearly as well.
Wow I never even thought of using a table saw to get the angles. A question about your finishes of the paper covered wings, do you prime first? I'm thinking of using some type of water based paint and applying it with an airbrush, any thoughts? Thank you
I probably could use a little less glue, but the weight, with the glue that I used, is NOT an issue. The panels shown in the video ended up being 84 grams ( a bit less after trimming the ends and the dihedral angle. 1 ounce = 28.35 grams. Divide 84 by 28.35 and you get 2.96 ounces. The assembled wing is therefore just shy of 6 ounces and this is a 4 FOOT wing with a 7" chord (before adding ailerons). Show me any other wing that big (and that STRONG) that weighs less than 6 ounces. One of the first planes that I built with this technique is my own design, loosely based on the Midwest Hots .40. It has a 38" wing span, and measures 35" from the rear edge of the rudder up to the tip of the spinner. This plane (Hots-e) fully stuffed (except for the fligth battery) weighs 15.1 ounces. I use a 3s 1000mah zippy compact 35C battery to fly this one. The battery weighs 3 ounces, so the all up weight is 18.1 ounces. It flies like an angel. I put 3 flights on it this evening in the calm air. I loafed around on the last flight, keeping the throttle at about 40% for the entire flight. I did lazy circles and a few loops and rolls. I was airborne for 11.5 minutes before the battery was done. I would NOT want this plane to be any lighter. It is perfectly balanced all around. If it was lighter, I wouldn't penetrate the wind nearly as well.
You'd just use the vacuum bag to draw the skin tight. It's a trick used when laying up the fiber glass. The vacuum flattens wrinkles and the like. The practice is most common in prepreg and is done between layers in order to keep problems from compounding..
I'm not sure what you mean by laminating film....are you talking about Monokote or one of the other iron on coverings? Or are you talking about the clear film used in a laminating press? Either one can't provide anywhere near the strength of glued paper. Monokote will stretch, even if you could get it uniformly bonded to the foam (probably impossible to do). The WHOLE reason for using paper and glue is STRENGTH. The finished wing is so strong that it needs no spar. Full size aircraft used a similar technique. The WWI Albatrosses had a plywood skin on the fuselage; the british Mosquito bomber had a stressed plywood skin over the entire aircraft that made it light but incredibly strong.
I think he means temperature sensitive laminating film sold by the roll & used to cover large pictures and charts/maps etc. It is also sold as "pouches" to cover books etc. It increase the weight by approx 30% if you use the 75 micron(3mil) as I do for planes the size you are building @@kuehn1953
Great video - thank you. Why make the ends pretty before trimming them off? Seems like wasted process. And yes, folks, there are 473 different ways this nice fellow COULD have done this, but this is what he showed. If YOU are so much better, where is the link to YOUR video?
John, I don't understand your question. I don't recall doing anything to make the ends pretty. If the question is about snipping the kraft paper and folding it over the ends in short pieces, that is done to get solid adhesion of the paper right out to the wing tip. If you don't do that, as the paper and glue shrink and dry you sometimes get some of the paper at the end of the wing panel that doesn't stay down firmly and you can end up with parts that are loose. This is seldom more than 1/2" or so, but I like to get it glued down solidly right to the tip of the panel. Hope that answers your question. If not please give me a clarification.
do you place the core in the foam saddles to ensure they cure straight? how do you finish them? this looks quite strong and light and easier than conventional balsa sheathing.
No, provided that the weather is nice, I put them outside in the sun and the wind, with minimal support so that they can dry on both sides at once. They WILL bow somewhat to one side....The side in the sun dries faster and shrinks BUT the other WILL catch up. I usually turn the wing a couple of times to even the drying. They will make you think that they are going to dry with a bow to them, but they straighten out. Brian Kuehn.
A friend of mine tried this technic few years ago and he allways had problems, on the drying process the wing was warping/bending... How to avoid this issue?
Do both sides at once....if you do just ONE side, you guarantee a warp because the paper shrinks as it dries. I do both sides at the same time (as per the video) AND I usually set the wing outside in the sun...and go out and turn it over a couple of times during the day. Even in sunlight it can take hours to dry. My finished wings end up straight.
Juan, sorry I haven't checked the comments here in a long time. I've never tried putting multiple layers of paper on a wing but it could certainly work. I think that instead of multiple paper layers, I would instead cut a spar slot in the foam. For a 2 meter wing I would suggest a 3/8" x 3/8" spruce spar, glued in with elmer's or wood glue or epoxy. If a sport model, put the spar on the top of the wing. If its a 3d plane, pattern plane, high wing loading, put spars top and bottom in the wing. Sounds like you may be building a glider? That adds a little to the complexity to the construction but its a good addition. Assuming a 2 piece wing joined at the center, adding a plywood plate in a slot behind the spar(s) adds a lot of strength. Fiberglass tape around the center joint is also a good addition. Hope this helps.
Yes, Elmers is a form of PVA (PolyVinylAcetate) glue. Any tan or brown wood glue would work just fine. Elmer's is cheaper than wood glues, so I use Elmers.
@@kuehn1953 actually that's not the case. Yellow glue like Titebond II is PVA. Elmer's and other white glues are alphatic resin. Elmer's makes a PVA glue. It's called Elmer's Carpenters Wood Glue
BEFORE wrap paper to wing you need sure add garbon fiber rod in wing center glued first. then can wrap paper top.but lot better have srhrink film cover than paper. no need paint or anythink have fulol ready and lot better cover wrap.need only cover film and iron heater and little heat hotairgun. lot better than this system. ofcourse this is good for poor men and if no need outside fly. but if use paper need paint this too and no good. lot better have cover plastic film.
I just completed construction of an 80-in photo drone to shoot to videos from a fixed wing using this technique I did cut a slot with a table saw for an 1/8-in by 3/4 full-length spar on the underside other than adding that spar the construction is exactly the same. The plane has flown it flies well the wing is plenty strong.
Brian Kuehn I probably could use a little less glue, but the weight, with the glue that I used, is NOT an issue. The panels shown in the video ended up being 84 grams ( a bit less after trimming the ends and the dihedral angle. 1 ounce = 28.35 grams. Divide 84 by 28.35 and you get 2.96 ounces. The assembled wing is therefore just shy of 6 ounces and this is a 4 FOOT wing with a 7" chord (before adding ailerons). Show me any other wing that big (and that STRONG) that weighs less than 6 ounces. One of the first planes that I built with this technique is my own design, loosely based on the Midwest Hots .40. It has a 38" wing span, and measures 35" from the rear edge of the rudder up to the tip of the spinner. This plane (Hots-e) fully stuffed (except for the fligth battery) weighs 15.1 ounces. I use a 3s 1000mah zippy compact 35C battery to fly this one. The battery weighs 3 ounces, so the all up weight is 18.1 ounces. It flies like an angel. I put 3 flights on it this evening in the calm air. I loafed around on the last flight, keeping the throttle at about 40% for the entire flight. I did lazy circles and a few loops and rolls. I was airborne for 11.5 minutes before the battery was done. I would NOT want this plane to be any lighter. It is perfectly balanced all around. If it was lighter, I wouldn't penetrate the wind nearly as well.
Wow I never even thought of using a table saw to get the angles. A question about your finishes of the paper covered wings, do you prime first? I'm thinking of using some type of water based paint and applying it with an airbrush, any thoughts? Thank you
Elmers glue is too heavy, even watered down...so to are water based primers & undercoats...they are full of heavy fillers...use aliphatic resin is a little lighter but...it has a MUCH higher compressive strength & just as good in tension as elmers...is much more ridgid & sands well...if want light...use nitrocellulose laquer...Duco...it binds to the paper wood fiber at the cell level & drys VERY light & fast...be mindfull though that cellulose laquer cracks easy if dinged...you can add a little..a little...pva as a flexi agent...& cellulose laquer is easy to repair or refinish just by spraying or rubbing thinners over it...re-melts it...there is a much stronger & lighter glue but gets more tecnical to handle with this paper & foam method...this is old skool stuff...from an oldy learned back in the 60s & 70s
