Wing Tips and Monokote

[Motorman]

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[Tim Wescott]

• Get a copy of Faye Stilley's Covering R/C Airplanes
• follow instructions

The short answer is that you make sure you've got a lot of excess 'coat hanging out, you grab it with a glove, and then you coach it over the wing tip while playing your heat gun over the part that needs to stick down.

I cannot describe the process in words -- you have to develop a feel for it.  The closest I can come is that you're trying to let the 'coat shrink in width so it'll fit over the tip, at the same time that you're preventing it from shrinking by pulling on it with your gloved hand.  You have to develop a touch.  I'm getting better, but I'm still not there yet.

If you use more than one material -- they're different!!!  The principle is the same, but the details are different.

http://www.powells.com/partner/30696/biblio/0911295208?p_isbn  -- On backorder
http://www.amazon.com/gp/product/0911295208/ref=cm_cr_mts_prod_img  -- Don't have a heart attack at the price!

[Dan McEntee]

If it's a solid tip I use the orange peel method and make some cuts to produce small wdeges, then overlap them as I seal them down. I lay them over like a roof shingle so they overlap towards the trailing edge. If it's a built up tip, I do the ornage peel thing also but you can take from rib to rib on the tip, and over lap the same.  It's like Tim says, easier to show you than to tell you.
  Type at you later,
    Dan McEntee

[Tim Wescott]

I used to use the orange-peel method.  Faye Stilley's method is actually both easier and nicer-looking, once you get good at it.

[Dave Denison]

A little more additional help for you, Tim and others have tried to describe to you what is involved with this pulling and shrinking and pushing technique with the Monocote, very difficult to describe.

I have the book in front of me by Faye and I'll try to give you just a quick summation of the high points and hopefully this will be enough for you to make it work on your own.

As Faye describes you're going to do several things simultaneously working slowly, shrink the material by applying heat and pulling pressure making sure that you do not stick the Monocote to the surface keep the Monocote high enough so it does not stick to the wing tip or itself. To do this you will need a well insulated glove, your heat gun will be working the Monocote right at your fingers or very close to them. As the Monocote shrinks and you see the wrinkles slowly disappearing at that point you can then pull the Monaco down on to the wing tip keeping strong pulling pressure and draping in a downward motion over the wing tip. Again, this is difficult to describe in fine detail, you might check YouTube for a video that will show just what the book is referring to. This is one of those tricky applications that requires practice, technique, and more practice to get right. I've been using monocote for 30 years plus and it is still not the easiest thing to do depending on the given shape of the wing tip you're working with. I hope this has helped you......... good luck

Regards
Dave
ama 41041

[Mark Scarborough]

step one,
buy Ultracote,,

 

[Dave Denison]

step one,
buy Ultracote,,___YES!!


step two:

Go through the same procedure as above....but use less pulling force.

 Regards.
Dave
ama41041

[Tim Wescott]

keeping strong pulling pressure and draping in a downward motion over the wing tip.

But not too strong -- if you pull too hard you'll pull wrinkles in the 'coat.  If you pull too little then it won't shrink right.  You do have to develop a feel.

I've gotten my hands on a bunch of surplus rolls of various covering materials, so I'm playing with all of them.  Monocoat is OK, but Ultracoat is easier, and if you're buying new, far less expensive for a 25 foot roll.  But if you absolutely positively have to use Monocoat, it'll work (that wing I show is 3/4 Monocoat, 1/4 Econocoat).

[Mike Griffin]

I also want to put a recommendation in for Ultracote and there are quite a few videos on You Tube showing how to do this.  The previous comments are spot on as far as getting a feel for it.  I still have problems trying to get a wrinkle free application.  I just takes a lot of practice...

Mike

[Garf]

You cannot do this with a flimsy tip. It needs to be able to take some abuse.

[Randy Ryan]

Thanks guys, I watched a couple videos. I've been trying to do it with an iron lol. The stuff in the video shrinks allot more than what I've got, will try ultrakote. Also need a tip for my heat gun. Hey, I finally have a use for all those left hand leather gloves I've got.

MM

With either as Tim says you develop a feel for it, you'll actually feel it stretch and relax a bit as you heat it. I don't like Ultra myself, but the new Monokote doesn't work anything like the old stuff used to, very low shrink.

[Tim Wescott]

Stuff shrinks more under a heat gun than it does under an iron.  Basically, when these heat shrink coatings get hot, they do two things: they shrink, and they get weak.  

When you put an iron on them really gently, the parts that get hot first shrink, and the other parts pull away from the iron and never get hot.  If you put the iron on firmly enough so that parts don't pull away, then you keep the material stretched.  In fact, you can leave a loose spot in a 'coat covering by putting a good hot iron in the middle of an open bay, gently pressing it into the material and then removing it quickly.  It'll stretch because of the pressure, and then not have enough time to shrink before it cools.

On the other hand when you use a heat gun, everything gets hot no matter what (in fact, the stuff will shrivel up in a ball and stick to itself if you don't control it).  So you can gently stretch it along the direction of the wing tip at the same time that it shrinks a lot across the direction of the wing tip.  The results are astonishing.

So just because your Monocoat (or whatever) isn't shrinking enough when you use an iron doesn't mean that it won't shrink plenty when you use a gun.

I'm defending Monocoat, here, but note that I don't necessarily favor the stuff -- its just that the thread seems to have taken on a "Monocoat is useless" tone.  Monocoat may not be as easy to apply as Ultracoat, but it's by no means a useless disaster.  I haven't decided yet which one has the best potential for giving you a really top-notch job in the end.

Make up your own mind, but I don't think that trying this out using the Monocoat that you have is necessarily going to lead to failure.  I'd be astonished if you did a wrinkle (an cuss-word) free job the first time with any material, so if you're going to switch to Ultracoat anyway, you may as well use up the Monocoat in the name of training.

[Tim Wescott]

With either as Tim says you develop a feel for it, you'll actually feel it stretch and relax a bit as you heat it. I don't like Ultra myself, but the new Monokote doesn't work anything like the new stuff does, very low shrink.

That's a grain of salt to take with anything anyone says about Monocoat.  I have an assortment that came from god only knows where, so I couldn't tell you for sure if I've got old or new, and I couldn't tell you that if I failed to meet joy with a particular roll it was because it was the new stuff or me.

[phil c]

I find I can do a tolerably good job using an iron.  Much the same method, but apply the iron just outboard of the last place the 'cote is stuck down.  Pull the covering in to stretch it but don't let it stick down.  Work around the tip so all the covering gets stretched without wrinkles.  Then go back around sticking half an inch or so down.  Then repeat, again stretching the covering ahead of where it is stuck down.    Finish the last half an inch after the covering has gotten to the centerline, pulling, stretching, and shrinking until at least 1/4 in. is stuck down past the centerline.  Pull it up slightly and trim it off smooth.  When you're ironing it down, do short sections, and inch or so, and let the covering cool off so it doesn't pull up doing the next inch.  A helper with a cold towel can help a lot.  Otherwise, use your thum.

[Randy Ryan]

That's a grain of salt to take with anything anyone says about Monocoat.  I have an assortment that came from god only knows where, so I couldn't tell you for sure if I've got old or new, and I couldn't tell you that if I failed to meet joy with a particular roll it was because it was the new stuff or me.

Sorry Tim, re-reading that I see where you got the wrong impression. I am a long time Monokote user, even used to do contract covering for some of our RC pattern guys here. The new Monokote just isn't what the original was. it does not shrink well and when it does shrink is seems to be directional, usually the wrong direction.

[Robert Redmon]

I have been using Monocoat since 1971, and (Like Randy) never had any particular problem producing excellent results on either solid or open surfaces. Tips and compound curves were easy after you got the hang of it (the heating, pulling, stretching, etc.). Heat guns only created problems for me as I tended to burn holes with them. However, about 10 years ago, this changed. None of the Monocoat I have purchased since has worked the way the original material did. It still works, but it is MUCH more difficult to achieve a really good finish with the new stuff than it was with the older material. As Randy says, it shrinks less and unevenly. The adhesive also seems to gas more. I have also had some difficulty with the adhesive layer separating from the mylar. I have been told it is now made in China and the suppliers of both the mylar and the colored adhesive are also there now. Whatever the reason, the "magic" is gone from the stuff. I really miss it, too, as I have always taken great pride in the finish of my planes. Painting/doping/etc. is and has always been rather problematic for me as I have an asthmatic reaction to most aromatic solvents. Before Monocoat, I just doped outside and/or suffered the consequences.

Recently, I (re)discovered Ultracoat (Oracover). I find that it applies much like the original Monocoat, but I sure wish it was a bit thinner. The mylar based Monocoat was thin enough that when applied and sealed properly, you could just barely see and/or feel seams. That seems impossible using Ultracoat, no matter what I try. The polyester material must be a little thicker, and no matter how hard I try, I can always feel the edges (seams).

FWIW

Bob

[richardhfcl]

Some Midwest stunt pilots have solved the wing tip covering problem by only building squared off wing tips.  They never have a problem covering the wing
tips!

[Tim Wescott]

I have been told it is now made in China

See my comments (rant?) here on things made in China: http://stunthanger.com/smf/index.php?topic=30289.msg296093#msg296093.  There is absolutely no reason that quality stuff can't be imported from China, as long as someone gives a rip and is willing to spend what it takes to get quality work.

[Randy Ryan]

See my comments (rant?) here on things made in China: http://stunthanger.com/smf/index.php?topic=30289.msg296093#msg296093.  There is absolutely no reason that quality stuff can't be imported from China, as long as someone gives a rip and is willing to spend what it takes to get quality work.

Your absolutely right and (fire suit zipped) there are some good quality products coming out of China. But as you say, without QC, anything they make is only a lookalike at best.

[john e. holliday]

I don't know or can't remember if i have said/stated this before.  I am a Monokote fan ever since they upgraded to the non sticky back stuff from the early years.   Sometimes you have to turn the heat up on the old Monokote iron.   Learned how to do that when I used the Coverite fabric material.   Remove the knob, reach inside with a screwdriver and turn the inner screw.   But then mark your iron or else when you use other covering materials, they will disappear if iron is held in place too long.   The latest plane I covered the wing tips with a separate peice of material.  Doen't look bad from 15 feet.

[Grady Widener]

Do the tips before covering the wing.
Make sure there's extra material to grab on to, but not tons as this can induce more wrinkles.
Tack strategically with iron typically on last rib cap-strip.
It's sometimes necessary to initially make a small slice (1/4 long) parallel to and at spar location to get things started as this is where geometry really gets compound at wing tip. Material locates forward and aft from wing high point at this position. Rotate and pull material around over planking so that the covering shifts inboard from already tacked cap-strip rib line. This makes material much flatter to start with as plastic proceeds to outer most portion of tip.
Using gun, heat, pull and slice as required, but not necessarily in any fixed order....it's an acquired feel  and I find the stuff shows you what needs to be done given a basic understanding of geometry.
Use iron to seal to tip plate depending on whether it's solid, molded or built up.
If built up, material must be free of wrinkles or bunching at tip plate on both top and bottom before using gun to taughten final alternating between top and bottom so as not to induce asymmetry per Flite Streak swoopy tip.

Best,
Grady

[john e. holliday]

I know on the modern aerobatic CL planes there is no problem with the rules in sheeting the last rib bay instead of using cap strips on the last two(Exception is I-Beam wings).   But, in classic, N-30,  Super 70's and Old Time, would we take a hit at the competition circle and be allowed to fly and/or get appearance points?

[Grady Widener]

[Joseph Lijoi]

I had an ARF PT19 (Ultracote) and an ARF Flite Streak (Monokote) in the trunk of my car during the summer for weeks on end and the Ultracote was far superior in staying wrinkle free. 

[dirty dan]

Part of the reason the guys are having trouble describing with the written word how to wrap plastic film around a wing tip is the seemingly contradictory act of in some spots shrinking the film and in other cases stretching film. We could write at length about this and never deliver what 20 minutes of practice would show as being effective.

As to heat guns versus irons, while I prefer the former they have shortcomings and a good iron (read: NOT a cheap, entry-level iron) can be very effective.

Not mentioned is the very real possibility of work-hardening film, especially when covering wing tips.

Dan