Covering This Wingtip??
 

I'm having a heck of a time with this wingtip. Its basically a Sticks tip, and the compound curve is severe. Has anyone done one like this, and can you please explain the technique involved. I've been heating, and stretching the MonoKote, but am always left with too much at the leading edge. Thank you for your help, and suggestions.
http://www.rcuniverse.com/forum/atta...mentid=2085678

That's why I like a soft balsa block from the gusset at the spar to leading edge shaped the same that the covering should look like.You need to form the covering over something.jeffo

I'd at least block the front and add some cross pieces between what's already there to help hold the covering up so that it's at least close to the desired shape

Really?? I know stick airplanes have wingtips like this, and I've seen many of them covered with the same compound curves, and no filler block.

It will be easier if you use two pieces of Monokote: one for the part from the short brace back and another for the front. I usually replace these with a carved and hollowed-out balsa block.

I see what your saying. I guess its the fact the covering doesn't have a surface to adhere to for when your stretching, and heating it.

Just iron a piece over lapping the blue part by about a 1/2in. Take your heating gun and stretch and stretch and stretch over the wing tip. Use a glove so you don't get burnt and sometimes you can get help with someone heating while you stretch. If there are still wrinkles after you stretch just heat them out with your heating gun. It might take a few tries but you can do it. Monokote stretches pretty good. Make sure you have plenty of extra monokote to pull on, atleast 2 or 3 inches.

Maybe that's what I've been doing wrong. I leave about an inch an a half. I guess I'm not leaving enough covering. I've pulled, and heated quite a bit. I try to preshrink the covering before attaching it but the taper at the leading edge is so severe I'm always left with extra material.

I guess instead of trying to preshrink I should try to stretch the covering around the tip.

I get close, but just can't get it to be tight. I know if I lock MonoKote down, and try to remove the wrinkles there already locked in making it all, but impossible to remove.

I'll practice. I just hate trying to remove MonoKote as it leaves the residual color behind if I want to do a redo.

What you need to remember is that with stick models, the area being covered is considerably less than what you're trying to cover in this build. Most use the supplied tissue to cover the model with so a little water tightens it right up. Along with the dope needed to hold the tissue to the wood, there's not a lot needed to cover with. I've built several Guillow's planes and, other than not breaking the sticks, putting your finger through the tissue is the hardest part

If you had used UltraKote, it would have been easy, especially if you had covered the tip prior to covering the wig itself

My past experience with Monokote/UltraKote this kind of tip, should have been done with one piece for the whole bottom of the wing and one whole piece for the whole top of the wing. Starting from the center of the wing. Trying to cover just the tip is extremely difficult, as you are experiencing. Do the bottom of the wing first. Iron down the covering at the center of the wing. Do not attach the leading edge of the wing or the trailing edge of the covering. With a heat glove and gun, pull the whole sheet of covering over the center of the tip. As it attaches, continue to pull the covering working forward and towards the trailing edge of the tip. Once secure, then heat and pull the leading edge of the wing covering until secure. Repeat for the trailing edge of the wing. The one mistake I see, is that you are trying to have very little edge on the blue part of the main wing. There just isn't enough material to stretch. Has to be a whole wing panel. Thus, as you pull it, the heat pulls off of the blue too. Repeat for the top of the wing. You are trying to do it with too small of a piece. Has to be one whole panel.

Here is a method I use when covering open structure wingtips. Hope this makes sense. Just let me know if you have any questions. The key is to keep the seam and edges cool when you shrink the open areas with your heat gun. Don't stay in one place to long, keep moving. Good Luck!

http://www.rcuniverse.com/forum/atta...mentid=2085801

Great diagram! I will try it that way, but I have to say using MonoKote at least to me isn't easy. It seems like it doesn't shrink enough to pull tight. I have no experience with Ultra Coat, but have to say I'm more than curious now to try it. This plane holds more sentimental value as its over 20 years old, and my father, and I learned to fly on this model prior to him passing.

I will do whatever it takes to get it right, but these tips aren't making it easy.

I tried preshrinking MonoKote again, and still didn't see really any shrinking. the covering appears to only form heat blisters, and become stiffer, and less pliable after applying heat. I'm only talking about 220-240 degrees with the iron. I'm not sure if its just my technique, or its this difficult to work with.

http://www.rcuniverse.com/forum/atta...mentid=2085804I was given a NIB ARF Ultra Stick and there was a lot of wing damage, this wing tip was so bad I just used my heat gun to soften the glue stick crap they used and removed the old tip and made a complete new one. Ribs were also broken on both wing halves so to get in and do all the repairs I removed all the covering from the bottoms then recovered. With these Horizon pieces of junk at least they used Ultrakote so getting the correct matching covering is easy. I just warm up the covering at the tip with my iron and stretch it over the tip and iron it down tight at the edges. I leave all the waste covering then turn up the iron a tad and run the iron over the top of the covering to shrink it tight then trim the waste and iron it down to the edge.
Nothing secret or needing any tricks. Ultra shrinks and holds very well so it is easy. The Chinakote from Hobby King is every bit as good if not better then Ultra and at 13 bucks for a 5 meter roll you can't beat the price.
After I ran my iron over all the open bays and sheeting to remove the sag and wrinkles I also went over the top of the wing and removed all the wrinkles and bubbles that were from the factory. The wing now looks better then new and no longer has all the broken ribs.
The covering isn't touching any of the supports inside the tips, it just lays tight from the last rib and the edge of the tip then gets tightened.

I prefer Ultracote. I have used both for number of years and switched to Ultracote exclusively unless recovering a plane that already has MonoKote. This is just my opinion as this topic appears to be like Chevy vs. Ford in the threads. All I know is I have actually covered wheel pants with ultracote because I can pull and stretch that stuff like crazy. Also I have found you need to use fairly fresh stuff whichever one you choose. I wrap all my covering rolls in plastic wrap once I am done to keep if fresh longer. There is nothing like the smell of hot Ultracote in the morning... LOL

I am assuming that the exisiting wing covering is Monocote. Monocote is a higher temp covering than Ultrakote. I would use a lower temp covering to patch over the Monocote so that you would not need to get very hot and affect the existing covering. I think UltraKote would be good here because you won't need to get it so hot, plus Ultrakote shrinks quite well. Also, you can use the Topflite Monocote adhesive/dissolver to rub off the coloring smudges that stuck to the existing covering, but make sure the dissolver is removed before you iron on the new covering. But the dissolver usage is optional and does add some complexity that you may not want.

As mentioned already, stick the covering around the perimeter with a lower temp setting just to make stick, but not shrink (the temps will vary based on which covering you are using). After you are 100% sure that the covering is glued down around the whole perimeter completely, then raise the temperature of the iron or heat gun and shrink it.

Nice work G.B. I have recovered 2 airplanes with the Chinacote recently and they came out nice, considering my lack of talent. I will recover a warbird next, now that I have had some good practice with the Chinacote.

Thanks, I had to repair both wing halves and removed only the bottom covering, I wanted to keep the graphics they have on the top. I have covered two planes with the Chinakote and found it goes on even better then Ultra. I had both planes out with me a couple times with the temps close to 90 degrees and like Ultra is doesn't sag or wrinkle in the heat. I'm very impressed with it and will now be using it exclusively from now on. Like Ultra the white glue that will squish out if too hot or too much pressure is used is removed with a rag and acetone.
This is the first time I have used the Ultra clear tinted covering and was also impressed with it too. Went down easy and shrunk well.

The chinacote I used has white backing instead of color that matches the covering. So, I also learned to rub off the white exposed edges with acetone or Topflite Monocote adhesive/dissolver. I also used transparent yellow chinacote and it was very good too.

Great information guys. That seems to be the majority opinion on Monokote. Ultracoat seems like a more viable solution along with the technique written above. Gray Beard excellent job on the rebuild, and wingtip. I would never know you touched it. Honestly after doing some research on Oracover which I know is Ultracoat in the states it seems to be a more well engineered covering. They didn't make it with the color integrated in the glue layer, so removing, or repositioning is possible without covering, or model damage.

The model I'm working on is a plane popular in the 80-mid 90's. A Rick Stick Cmodel edition, which I removed the included engine which was a Tiger Shark .46, and installed a Rossi .45 black head. The only reason I went with MonoKote was that's what was used on the model when I found her at my hobby shop. She was showing the typical signs of her coverings age of wrinkles, and lifting in certain areas. I just wanted to touch her up, but didn't realize recovering with TF MonoKote would be so difficult. I can't see literally any shrink take place when heated. I was thinking it was simply my lack of skill, but after doing a little research found that apparently it's an epidemic with it. I won't debate which covering is better, cause I haven't used UltraCoat yet, but looking at Oracover's website, and how they provide a temperature to tack then another to shrink simply is pure logic.

I also couldn't believe the amount of covering color choices they have, and even exact color matched paint! I look forward to trying it, and posting my results.
Gray Beard clarified what I thought about no special tricks are required with it once the proper covering is used.

I started out using Mono and then they changed the formula and shrinking was hit or miss depending on the color so I went to the Ultra and was amazed at how easy it is to put on and how well it shrinks. They don't have as many colors as Mono though. They did have there matching paint too but we can't get it in the states any longer?? I have some of the paint on hand but when it's gone it's gone!!
I was given a roll of the Chinakote last year to try and wow, really good stuff!!! I have only used the yellow though but my next order I will try the other colors.I still use Mono but only for trim work. Here in the desert our summers are quite warm {Understatement!} and MOno tends to sag and wrinkle in our heat. Once Ultra has been cured it has no problems with the heat. I do most of my work in the summer and when I finish a plane I set it in the hot sun before I do any trim work, take it back into the shop and shrink it again then repeat until it no longer sags.
So far the Chinakote hasn't sagged and I haven't cured it on either plane.
People have there favorites and to debate the brand of covering here on RCU has been beaten to death over the years. So far for me it has been Ultra and China and because of the price I have now become a big fan of the Chinakote and sticking with it. When I got this ARF it came with a roll of the Ultra so I knew there wouldn't be a problem.
I have had a problem with the Ultra chrome/silver and the Mono was a lot better so even Ultra isn't fool proof.

I don't like Monokote I don't think it stretches as well as Ultracote, but none the less, Leave about 3 inches overhang and use only the heat gun and with a gloved hand, stretch the covering while
heating. Work all wrinkles out with heat. I've done it on stick wing tips and it works great.

CModel, try taking a piece of monokote about 2" larger all around compared to the area you are covering, adhere it to the edge of the wing first, keeping at least a quarter of Monokote at the edge, then pull it by hand down to the center edge of the wing and all around the edges, for myself the secret here is to keep the heat off the Monokote that you are putting on, Just enough heat to stick it to the edges. Making sure all the edges are adhered, use a heat gun and keep it fairly far away just enough to start seeing the wrinkles go away, they will continue to go away even after the heat is taken away. Patience is the key here. Try not to shrink the Monokoe with the iron when putting it on, so that when you are ready to use the heat gun, you will have all the shrinkability the monokote has to offer, because you have not used it up until the heat gun is applied, Bob.

Pre-shrink monokote? Please define. I've used a lot of monokote over the years and have never heard of, much less thought of, such a thing.

I've done a repair like this before. It can be done in one piece of covering. The trick is to use your heat gun for application and stretch the covering at the same time you are shrinking it. Iron the covering down without shrinking it on the flat part of the wing, stopping where the curve at the leading edge starts to tighten. Then you can pull on the covering at the front to stretch it as you use the heat gun to activate the adhesive. That will pull most of the wrinkles out of that annoying section between the spar and leading edge on the wingtip. Then use the same pulling technique to adhere the covering to the edge of the wingtip by wrapping the covering around and pulling from the bottom while heating the top. You'll need to aim the heat away from the first seam you made, so you'll need a glove to protect your hand. Once it's stuck all the way around, you can keep using the heat gun to wrap the covering around the radius of the wingtip. The last step, if needed, is to use the iron at shrinking temperature to shrink out any looseness that remains over the open structure.

What I am saying is if I take a piece of monokote say 6" by 3" and touch it with the iron and get it to shrink before it is adhered to an area where I would like it, when I do get all the edges stuck down and try to shrink it with the heat gun or iron, it will not SHRINK as much as it could have, because I shrank it before the edges where adhered. So if I go around the edges and stick it down and not heat up the main body of the monokote, I will be able to get more shrinkage because I haven't partially shrank it already, Bob. If you read the instructions that come with the roll, somewhere it used to say that Monokote is tri-axisually stretched when it is made so that when it is heated and shrunk it shrinks evenly. For the most part, all I am saying is that Monokote will only shrink so much, so if you heat this piece and start shrinking it before all the edges are stuck down, you lose a small bit of shrinkability, which in this case the area is really small and you need all you can get. Directions also say when covering a wing panel, smooth out the Monokote and seal all the edges securely and the start shrinking, so covering will pull tight over the full panel. That is why you do not adhere covering to each wing rib bay, because in so doing, the covering can only shrink in this small area and not the whole panel, Bob.

I have to say thank you for all your suggestions, but I've tried working the MonoKote almost going through an entire roll. A tip with this many compound curves is very difficult, and while talking about tacking ,and shrinking the covering when it adheres sounds plausible I simply am left with to much covering at the leading edge. If I try not to shrink the covering, and simply attach it then the amount of excess becomes even larger. MonoKote only has an available shrink of about 10%, so I'm not saying it can't be used on these tips, but with an investment of how much "trial, and error time"?

I'm about to buy some Ultra Coat, and give it a shot. I have researched their site, and they offer some outstanding instructions for download on Oracovers website. They really explain in great detail about using the two temperatures one to adhere, and one to shrink. They also explain that the covering when shrinking at 300 degrees does so in percentages easily exceeding MonoKote.
I know it's been a long time debate as which covering you prefer, but that's a very hard detail to overlook considering how much time it saves, and error correction is as simple as heating an lifting the covering without fear of the color being left on the model.

Check out the chart I attached with Ultra Coats details on its ability to shrink. MonoKote simply doesn't offer that. You must apply MonoKote virtually wrinkle free from the start, or you risk locking them in place. http://www.rcuniverse.com/forum/atta...mentid=2086008

If you will do what I described, you will get a smooth finish. The trick is to stretch it along the line where you are attaching it to the existing covering. That will pull the wrinkle out of that tight compound curve at the front. It won't pull all of it out, but it will pull it enough that a secondary shrink will finish the job.

Jester,

I'm trying to envision what your describing in my mind. I have stretched MonoKote to apply it multiple times, and one thing I know for certain is that when you stretch it you distort it. If I stretch the covering towards the leading edge while its tacked to the flat area of the wing the seam from the new piece of covering will distort, and no longer be straight. It's like stretching pin striping you can stretch it, but the stress on the material makes its line uneven. Maybe you could do it as I'm certainly no expert, but I believe the real issue here is the amount of shrink I have to work with. The leading edge taper is tight with a radius bend as well. I thought even pulling the covering diagonally towards the leading edge while being heated would work, but I simply can't produce the amount of shrink required to tighten the covering, while pulling, and trying to keep the covering from attaching itself to the wing to soon.

Honestly it should never be this difficult. It could very well be my technique, but judging from all the hundreds of posts on how difficult this covering is to work with I might as well try Ultra Coat. I've spent at least 6 hours trying to accomplish two wingtips, and could have literally built a new wing in that amount of time. I think MonoKote is fine for flat surfaces, and typical wingtips where the compound curve isn't quite as extreme. I had no problems applying it to other surfaces, it's simply not modeler friendly in this case.

A roll of covering for $16 is well worth my time, and effort to see if it's a matter of skill, or product.

Not all Mono will shrink at all so it may be the covering itself. Have you tried starting at the leading edge first and moving the covering from front to back? It may help but if you have a roll that isn't going to shrink there really is no good answer at all. Last time I bought a roll of Mono it was for a students new plane. The kid spotted a plane at an IMAC event that he fell in love with so I had him take a photo of it so we could cover his kit built plane just like it. The plane had a lot of a green in it and sure enough the green we had wouldn't shrink. This was on an open bay wing no less. Sometimes it's no an operator problem. There are several colors that are made by all three manufactures that are a good color match.
It just sounds more like a product problem then anything else.

Gray Beard I totally agree with you. I think its a product issue. I'm going to post my results with Ultra Coat when I get it. Thank you for your support. I've read many threads on how user friendly it is, and like you wrote earlier there really isn't any tricks required it simply does what its meant to do.

Mono used to be like that, I started using it in the 60s when it first came out. Used my mothers iron until I got caught!! About 15 years ago they changed the formula and it sometimes works very well and sometimes not at all. That's when I tried Ultra and never went back.
I enjoy covering, I find it relaxing and don't feel like it should be work or have to be manipulated too much. I do need to do a few things differently then others but it is due to the climate here, really can be hot and it's always dry so I cure the Ultra before I put on the trim. I covered my last two builds during the winter or late part of fall and it wasn't hot enough to cure the covering. It has been warm here already and I took both my new planes out when it was close to 90 and so far I haven't gotten a sag or wrinkle in this Chinakote from Hobby KIng. At half the price and a 5 meter roll I really am sold on the stuff. It's even easier to put on then Ultra.

http://www.rcuniverse.com/forum/atta...mentid=2086077http://www.rcuniverse.com/forum/atta...mentid=2086078This is just a photo of before and after on an elevator half using the Chinakote. It is on a 90 inch span plane with a big cord and I did the yellow with one roll and had some left over. I never used my heat gun to shrink the covering at all. The covering may be in the build thread? Prime Cut +20 in kit building. I don't recall if I showed the covering or not, maybe??

It's amazing at that price. I look forward to trying their brand as well. I research all the components I buy from China, and honestly haven't been disappointed in any. Clevis's, pushrods, carbon, all have been excellent, and cheaper than typical stateside prices.

The first pic looks almost perfect even prior to shrinking. It looks like you just touched it up on the second after pic with a slight shrink, and no need for a heat gun. I'm personally not a huge fan of the heat gun as I feel I can control the exact heated area with my irons.

Excellent work!

Hobyhing stocks chinacoat in their USA warehouse so you dont have to go to china for it.
Hobbyparts carries it under a different name as does several other importers.
I am done with monocoat.

I buy everything from the U.S. warehouse too. I don't buy very much of anything from HK and other then a roll of covering I haven't ordered from them in about two years. Then it was just items for my electric plane. The prices can't be beat but there is no customer service and shipping will kill you. We have a group of guys here that ordered a lot from them so everyone got together and placed one big order.
The covering is usually in stock here state side and shipping is cheap plus it is in your hands in about three days.

Gray Beard, your were dead on. It's the covering. I will post my results shortly. Oracover aka Ultra Coat is almost to easy to use. I practiced with a small piece to see how well it shrunk, and to get used to the glue adhesion. I can actually feel the adhesive unlike MonoKote, and the repositioning without the color bleeding is amazing. This is my first time using it, but Ultra is by far a better product.

I will post pics shortly. The wingtips didn't require really any special technique other than what I did when using MonoKote.

Thank you all for your support.

If you think that is easy then Solartex will freak you out, it will make anyone look like a master coverer. The Chinakote is just like the Ultra but I haven't tried lifting it to see if the color stays on or not?
I read all the time how people manipulate Mono to get it to go on without wrinkles but yadayadayada, who needs to mess with it and why bother when there are better products on the market and for a lot less money.
Covering should be fun and easy, not work. At one time Mono was that way.
One thing is that you can't always find a color match for the Ultra. They used to have a very good paint that was a perfect match but we can no longer get it.

Grey,

This may sound odd, but now the only issue is I keep getting the color separating from when I shrink the leading edges compound curve. I can get it drum tight, and perfect, but around the edge of the tip it appears the covering is under, so much stress from shrinking its breaking the pattern of black, and white checkered Ultra Coat like color separation, but with no wrinkles. I'm not sure if I'm actually shrinking it to much, or missing an application technique. Other than the solid wood edge of the tip where the severe compound curve is at the leading edge the rest of the tip comes out perfect.

I'm not sure if I'm just splitting hairs, or if I can try a different method.

Photos help but if your talking about some color squishing out the seam then just remove it with acetone or alcohol. I have never seen ultra separate as I'm seeing it in my minds eye. Are you overlapping the covering so it's being glued onto the other side or is it slipping off the wood as you shrink?
Your just covering the wing tips? You iron it down with an overlap then ironing it down to the outer wing tip wood then with your iron shrinking the covering? Covering sticks to covering the best, once they touch they are there until you pull it off. I just don't understand what problem your having.