RC guys! I need help with Monokote

[DrewBlows]

I'm building a .40 Cub by Great Planes. It's the first RC that I have built and have been able to get to the point were I need to cover it. The only problem is that I can't figure out how to put the Monokote covering on without wrinkles. I have put a lot of time and effort into this project and am very proud of the work that I have already done. I think that if the skin is wrinkled it will look like crap.

Anyway, I bought a small modeling iron to apply it, but I just can't seem to get the wrinkles out. From what I have read it is supposed to shrink, but it doesn't look like it is shrinking very much when I apply heat. I have tried a little heat, a lot of heat (this just leaves black marks), and every thing in between. Is this stuff really this hard to work with? I am getting frustrated to the point that I really don't want to work on it anymore (why have a hobby if it makes you mad). The only thing that I can think of (other than my technique really sucks) is that due to takeing a new job, moving, general laziness, ect. I took a year and a half break while working on this project. During that time the monokote (still in the package) sat in storage where the temperature ranged from zero in the winter to over 90 in the summer. Is it possible that while sitting it lost some of its shrinkability?

Any advice would be helpful. If I can't do it I will try to find someone to do it professionally. But as much work as I have already put into it I would like to finish it.

 

[jarhead]

Have you tried a heat gun? I'm not talking about a hair dryer. I had success on a model I built many years ago, circa 1982. I used an electric heat gun that can be used to blow extremely hot air onto a surface, typically sold in hardware stores for people to remove old paint from siding on a house. I practiced with pieces of scrap material until I got the technique of getting the distance from the surface right, and the time applying it right. It seemed to work for me, and I did get a wrinkle free result.

You must practice, as it is very easy to apply too much heat and really get bad results.

 

[RJPilott]

Practice, practice, practice.

Get a heat gun. Top Flite has one relatively cheap.

Take a small part (elevator, rudder, aileron) and practice with it.

Cover the bottom first, then the top

use the highest heat setting at first, then back off on the heat till you get an idea how much you need to tack

Tack down the trailing edge first, working from the center of the trailing edge out to the edges.

Then pull the kote and tack down the leading edge in the center, working your way to the edges, most wrinkles should pull out during this

When all edges are tacked, grab the handy dandy heat gun and place it one to two inches above the kote in the center of the part you're working. Melt some holes in it to see how it behaves and amount of heat needed to shrink the kote. You will see the Kote start to shrink like a drum. After you are done, rip it off and repeat till you get good at it.

Also, before i forget, did you take the protective coating off the back of the kote? there is a plastic covering on the "sticky" side of the monokote, that needs to be removed first. Read the directions that came with the monokote. and practice practice practice...

here is a link to a good forum for tips on everything RC...

http://www.rcuniverse.com/forum/forumid_85/tt.htm

good luck...

 

[RJPilott]

This is the iron to use... i never used the sock, doesnt let enough heat through imo. If you are using the sock, that could be part of your problem. Take the sock off.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHZ17&P=ML

This is the heat gun....

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHZ16&P=7

 

[aucfi]

Great plane to build

I recommend the sock. Also, be sure your put the monokote on the surface the correct way (tacky side down, shiny up). The age of the monokote may affect its ability to shrink. Might be worth a shot to buy some new material.

Also, as you apply heat to the monokote, pull it in whatever direction it takes to get the wrinkles out.

If you really want brownie points and have the resources, use dope and fabric. Ive covered a few with this process and its quite fun. Only downside is dope and fabric are obviously heavier than monokote.

Good luck!

au

 

[gern_blanston]

...as you apply heat to the monokote, pull it in whatever direction it takes to get the wrinkles out.

Yup. Stretch and pull as you apply it to get it reasonably tight before you try to shrink it. And get a heat gun.

 

[RJPilott]

Dont go too crazy and pull too hard during tack. Pull just enough to get the wrinkles relatively smooth before shrink. Otherwise you might warp the part you're working on and then you'll get really frustrated. But there are tricks to getting warps out as well. Practice covering and shrinking first.

aucfi is right about dope and silk. i did a Great Planes J-3 in silk. Came out awesome, but its ALOT of work. I recommend to stick with your kote for now.

As far as the sock, mainly it is used to prevent scratches in kote while shrinking. But you'll have a heat gun for that. Some people like it, some dont. I prefer not to use it. Once you get really good with the heat gun, you'll learn how to tack with the gun and a glove while never having to worry about anything touching the kote besides air.

 

[DrewBlows]

Thanks for the advice guys. I have the top flite iron already, and my Dad says he's got a heat gun. I did pull the film off the back, that would be an easy mistake to make. I guess my biggest problem is that I just haven't seen it done before. From what you guys are saying I probably just need to practice some more (and learn patience). I have an aileron that I have already been "practicing" on. When I pulled the "practice" monokote off, it took a small amount of wood with it. It seems that if I do that too many times I may screw up the piece. Is it really taking enough off to matter? I could rig up a practice jig from scrap, I suppose.

Anyway, thanks for the advice. It's easy to get frustrated with these projects (especially the first one) and it's good to get some encouragement along the way.

More about the model. It's pretty much stock, except that I ordered a "Super Cub" cowl, and rigged it for floats (my next project). I am modeling it after the Supber Cub on floats that Western Michigan University (my Alma Matter) owns. The real airplane (which unfortunately I have never flown) has a pegasis on the tail which I would like to replicate, but am not sure how to go about. It's a pretty sweet airplane. I have an OS .46FX engine with a Pitts muffler and older Futaba radios. I would like to fly it, but am scared that I would wreck it (I have some trainer experience, but not much). I may get someone else to test fly it, or if not I am going to hang it in my parent's house.

I'd be interested in hearing of other projects that you guys are doing, that could be a pretty interesting thread.

 

[RJPilott]

You're right, we're all busy telling you how to put it on, we forgot to tell you how to take it off.

Heat the kote as you rip it off. It shouldnt take much wood with it, if any at all. A jig is a good idea while you practice the first steps. Make one similiar to an airplane part with compound curves.. etc..

Definitely check that rcuniverse link above. I believe there is a company that makes decals from pictures. Take some pictures of the image you want, provide dimensions and theyll make a decal for you. I forget the name of it, but you will definitely find it on rcuniverse. Everyone is very helpful on that site.

As for my planes, i have the J-3, a Top Flite Gold Edition F4U with flaps and retracts, and a Sig Bonanza with retracts.

Good luck with your project. Keep us updated...

 

[ms6073]

I guess my biggest problem is that I just haven't seen it done before.

Take a look at this link from the Monokote website (includes pictures): http://www.monokote.com/monoinst1.html