hi , i just spent an hour getting wrinkles out of all my planes to get ready to fly all day today. ? is why do i have all these wrinkles ? is it the wheather getting cooler and dryer? i live in phoenix all my planes looked good the last time i flew 2 weeks ago. today they looked like the arfs right out of the box not tight at all .anybody know why this happens or how to stop it?
thank you
mark eisenhut

i guess i can live with this problem when you consider that it was a nice 72* wind calm and about 15 flights and no broken planes  nice day. beats shoveling snow.
thanks
mark

I'm far from being a Monokote "Pro", but two tips are said to work very well in reducing your problem.

First, don't apply Monokote to bare wood. Seal the wood with a couple of coats of clear dope first; Nitrate is fine. Sand well (down to 400-grit) and then vacuum, tack rag, vacuum again.

Second, don't think of Monokote as a "heat and shring covering. Rather, adopt the "heat and stretch" technique. The tighter you get the Monokote before heat-shrinking, the less "creep" you will have.

Hi Mark,

I know I run the risk of being tared and feathered for saying this on this "painters" forum, but: "I love Monokote" ;-) I am far from being an expert, but after using it for the past 37 years, I have learned a few things about how it behaves. Or in this case: how it misbehaves!

Most people still think that it is the Monokote that is moving around, stretching, and contracting and causing the wrinkles we all hate. It does move a little, but the real problem is with our wood! It absorbs enough moisture to enlarge just enough to cause our problems when it contracts again.

We usually build inside where the wood is relatively full of moisture and the whole plane is just a little bit larger than it will be when we take it out into the sun where it will dry the wood making the whole plane shrink just a little bit. This leaves the Monokote loose, with those ugly wrinkles.

The solution is to get your plane out in the sun on a warm, perferably dry, day. Leave it there until it wrinkles. Then use your heat gun, and/or iron with a sock, to shrink the Monokote to conform to your now "slightly smaller" plane. I'm so fanatical about it that I run an extension outside so I can shrink it in the sun!

I do this with ALL my planes. RC and CL. Sometimes it takes doing it a few times, but then it is wrinkle free FOREVER! I have an Olympic II sailplane that is now 30 years old, and the MonoKote is still tight as a drum, even in the sun. I also have a 30+ year old "TF Combat Streak" that flys as both an RC plane and a CL plane that is also wrinkle free.

Now you can begin to see why our ARFs come with some wrinkles. My guess is that they leave the factory in "humid" China, (across a wet ocean,) with PERFECT Monokote jobs. You can imagine how good those people are after covering their "1,000 th" plane! ;-)

Of course, it goes without saying, that all the other suggestions you hear are helpful. Good wood prep, smooth, and dust free, will help. Also, when you use the heat gun, it really helps to use the Monokote mitten to press down on the film, while it is hot, to ensure it sticks to the wood.

I hope this helps with your problem. Please let us know how it all comes out.

My question about Monokote is the difference in handling characteristics  between colors. Some colors are easier to apply and seem to come out better. Also, some wingtips give me fits. I have had to cover some tips in several pieces.

Even better than dope on the airframe is a material at the hobby shop call Stixit. I was stunned how much stronger the retention of the adhesive was with this stuff over anything else I have tested. It is brushed on and then needs to be sanded down to get a smooth finish. I Brushed on one coat on a test strip and sanded one side to 400 grit and the other unsanded 400 surface with a coat brushed on. The final finish at 400 grit was equivalent to being stuck down to 400 grit sanded balsa. The unsanded brushed on surface was like about 180 grit sanded balsa and monocoted surface. Adhesion strength difference though on the 400 grit sanded and non sanded was almost identical. Good stuff and it works with Ultracote as well even though it is not mentioned on the label.

bob branch

All polyester plastics will reach a point where they will shrink no further. Knowing that use the minimum amount of heat necessary to shrink the material because when you need to reshrink it, it takes a higher heat to get the effect. So you have only a few shots to achieve total taughtness or forever live with the wrinkles. Better to pull the stuff as tight as possible when putting it on. For wing tips I usually use the gun. Heat the stuff as your getting ready to drop it over the tip. You'll find that even the most difficult tip will cover easily.
 There are only 2 downsides to Monokote, one is the relatively high temp needed yo attach the stuff and the other is the shelf life of the product. Believe me you do not want to use old Kote it's really not pleasent to work with and in that instance you will need some help keeping it attached and streched.
Sunlight has the same effect as on a painted surface it fades and with the UV exposure it becomes brittle. You have to keep it moisturized and like all finishes it's better to keep it covered till ready to fly.
Having painted or plastisized I prefer to use film as I'm sick of the smell of paint and it's incredably expensive. Whoever named plastic covering $cote hasn't painted a plane in awhile.
Dennis

FWIW In my experience, the transparant seems to be a bit less flexible. perhaps brittle would be a more translatable term? not that it is brittle, just in comparison to the colored opaque covering it seems less pliable, thats the word!
Its kinda cool though, and if you paint the fuselage, use candy colors over pearl, nice effect to match the transparant color.
sorry but I have all the cool stuff to paint with at my fingertips.......
another note, seems like the pearl colors tend to move the pigment/adhesive more readily which shows through when you really work a wingtip to conform. IE distort the pearl pattern