SquirlNutZipper

My Feedback: (9)

OK I have to admit, I'm still terrible at covering. I studied the Fine Arts and Industrial Design so you'd figure someone of my background and experience should be compitent at laying down some plastic wrap around a model and have it look somewhat professional. No way!

In fact, most of the time I'd actually rather be at the dentist than covering that sweet build I've just completed.

What is it with the stuff I'm missing? I tack here tack there, stretch here pull there but still I always get these wrinkles and lumpy edge lines.

I could really use some pointers or hands on training.

On a side note does anyone have advice on silk and dope covering? Haven't done it in over twenty years and two models of mine will be needing that treatment shortly.

Much appreciated,

A Very Frustrated Alex.

rainedave

My Feedback: (1)

I here you Alex. I've probably only done one or two plastic film jobs in my life that didn't have wrinkles, sags or bubbles. Maybe not at first, but after a few days in the sun they always start to show up for me.

Here's what I did. I quit using iron-on plastic film altogether. I'll never use it again.

Although I wouldn't recommend it on models smaller than .15 size because of weight issues, the best kept secret in the whole, entire hobby is Sig Koverall. You can attach it with Stixit or nitrate dope (better). It stretches around curves, shrinks drum tight and will not sag wrinkle or bubble. But, you have to paint it. The good thing is that the weave is so fine that two coats of dope will completely seal the fabric. As you know, silk can take six or more coats to fill all the pin holes. I covered my UFO wing with it and I'm completely happy with the results. It's now my covering of choice for larger planes. And, I know that it will never sag, wrinkle, bubble or peel up around the edges. Ever.

For 1/2A, Esaki tissue is hard to beat. I've also used Worldtex and 21st Century fabric. I might try covering a 1/2A plane with Koverall and simply clear coat it without using colors. That will still be lighter than plastic film. Monokote is actually very heavy compared to tissue or silk.

The two most important tips for covering with tissue or silk are:

1.) Coat the framework with three full-strength coats of nitrate dope and let it dry (butyrate has less solids and doesn't adhere the covering as well). You can sand off any lumps or runs.

2.) Lay the covering onto the framework and brush straight thinner onto the material over the wood. Rub the thinner with your finger to dissolve the nitrate below. This will stick the material to the wood like glue. Never use dope to attach the covering, use thinner. A lot of people don't realize that it's the process of dissolving the underlying nitrate that adheres the covering, not more dope. Thinner does two things that more dope doesn't do: it dissolves the nitrate easier and it evaporates and dries faster so you don't have to hold the covering in place as long, usually only a few seconds and it's stuck down.

Once the covering is adhered mist it with water to shrink it. With tissue all you need are two 50/50 nitrate/thinner coats. Silk will take several more. When these coats are dry, finish the job with two more coats of 50/50 butyrate/thinner to fuel proof the model. You may want to add a couple more fuel-proofing coats of butyrate around the nose.

Let the model cure for no less than a week. The dope will continue to shrink.

SquirlNutZipper

My Feedback: (9)

Excellent! Thank you so very much. I just may be a convert to the "old" way here. More like the art materials I'm used to dealing with.

rainedave

My Feedback: (1)

The success of Monokote and the other plastic films is probably the most bizarre aspect of r/c history. Thousands and thousands of modelers who have never even covered planes with silk, tissue or Koverall insist Monokote is easier to use. Advertising and the tendency to simply follow what everyone else at the field is doing probably led to the acceptance of that myth. At some point, faster got conflated with easier. Monokote is faster, but it's not easier. The main reason is that applying plastic film takes three hands. One to hold the iron and two to position, hold and stretch the covering. Tissue and fabric only take two hands to apply. And, it can be lifted and re-positioned as many times as you need, just re-dissolve the nitrate with a brush of thinner and pull it up. Modeling is my favorite hobby and I don't rush it, I savor it. So, if the covering stage takes a bit longer, all the better.

Mr67Stang

Just a question as I am new to the old ways here. Is silk/tissue with dope and paint any lighter than monocoat? my understanding was that the silk/tissue's advantage was that you would be less likely to warp a lightly built frame than shrinking plastic film over the frail skeleton.

Andrew

SNZ --

I do the same as Rainedave with a couple of minor differences. My first coat of nitrate is thinned from 33/66 to 50/50 -- I feel that I get a little better penetration with the first thinned coat. The remaining coats are full strength. Dope will raise the grain and make the balsa feel like sandpaper -- I like to give it a quick sanding between coats. If the wood is really porous, you may want to use a commercial nitrate sanding sealer or add talcum powder to thicken the dope. Sand to a glass smooth finish before covering -- a gnat's hair will show up under silk or silkspan. I use nitrate to seal open areas such as rib bays or other places where the covering is not supported. If I have covered the fuselage and it is solid, then I use only low-shrink butyrate. High shrink nitrate or butyrate will curl balsa as it tightens. Be careful not to use too thick a coating where you have 90 degree angles, such as stab to fuselage and rudder to fuselage joints. As the dope shrinks, it can pull away leaving a brittle bridge of dope that will crack thru.

Use nitrate first - it's a great adhesive, but not fuel proof. Nitrate will not stick to butyrate, but butyrate sticks well to nitrate. Once you lay down a coat of butyrate, you're done with nitrate. Both need to be thinned to brush well -- except the adhesion coats. You can thin up to 50/50 to spray. I have also used lightweight silkspan to cover the fuselage and other sheet surfaces -- use one underlying coat to seal and serve as an adhesive -- I add the silkspan dry and just paint over with thinned nitrate. If the wood is really porous, the silkspan saves me from a lot of filling and sanding, plus adds some strength. Over these areas, use low shrink only, or you will bow the wood.

Lastly, be careful when painting open areas with thinned dope -- it can run thru and puddle on the underside leaving a bullseye. You can either paint from the bottom or spray.

treedog

HEY sqirrlenut i found something interesting about monocote by accident. I tryed using an iron on it and it left a few wrinkles so i got out my heat gun and set it on a low to medium setting and held it at a foot of distance and slowly moved it closer to the film an walla all the wrinkles slowly vanished. just a place to start if the iron doesn't work
Td

SquirlNutZipper

My Feedback: (9)

Thanks everyone, I really do thank you but it's come to the area of... , OK, now I'm back to the point of Oil vs Acrylic and which canvas to tack and which is the best way to do so and what is the best way to thin the paints or how long to let them dry. Oh yes, and lets not forget the proper way to apply goush.

I can see this is very much an artist's field and that which suits individual is that which suits the individual.

I guess everyone has their own preferences based on their own styles. Maybe the best thing for me to do is some experimentation to find which technique fits me.

Some scraps are calling my name.

Thank you very much, all of you!

I'll let you know which formula works. For myself and my own style that is.

As for the heat gun from a distance and plastic covering... it's looking more and more feasable. Again the oil vs acrylic discusion...

Andrew

As far as using dope, there's not a hill of beans difference in the approach David takes and what I use. Dope has been around a long time, since before WWI and most of us that are long in the tooth grew up using it and listening to our mothers complain about the smell (to me, it has always smelled like fun). I covered my first plane using colored tissue probably over 45 years ago. In this unsettled world, if mothers had a choice between the dope the children are exposed to today and nitrate or butyrate, the lacquers would win hands down.

I can't cover with plastic -- it frustrates me to no end. I'm sure when folks look at one of my planes with plastic, they are thinking if it is constructed as badly on the inside as it looks on the outside, I'm packing up and leaving before that thing gets in the air.[]I

digital_trucker

Just to toss another method into the mix....I've had good results adhering tissue with an Elmer's Glue Stick. Gotta wait for it to dry well before you start doping, though.

ptulmer

My Feedback: (5)

Econokote is by far the easiest plastic covering. For a painted finish (if you don't want to sniff dope) the Nelson paints are the lightest I've used. I sprayed Nelson black onto a Blink until it was too thick and after it dried my postal scale couldn't measure a difference from before.
Doculam is a good base for a paint job on 1/2a. Lighter than Koverall (which I love, too) and pretty easy to work with once you know how.

BSARGE

Where do you buy silk, tissue and dope from now? I remember in the late 80s buying it from SIG....

-Bill

eroc144

My Feedback: (1)

Both Sig or Brodak's cary silkspan. I'm sure there are others too.

www.sigmfg.com
www.brodak.com

combatpigg

My Feedback: (3)

Anyone having trouble with iron on film is using too high of a heat to apply it. If the covering gets shrunk before it has been positioned properly, then there is not enough shrink left over after the distorted film gets laid down. Use the least amount of heat to get the film stretched out and positioned......with low heat you can also reposition the film, before you begin sealing it permanently to the wood and shrinking it with higher heat. A well done film job by a rookie will take half the time of a doped covering job done by a pro.

rrragmanliam

My Feedback: (1)

Sory Dave but I completly disagree with your assesment of iron on covering. I'll admit that I was never the best coverer with dope and tissue/silk but IMO the plastic films have it beat by a mile. I've covered plenty of planes with just two hands. It's requires fewer steps, is faster and easier IMO. As with dope and silk you just need to learn the techniques to apply it.

Darren

rainedave

My Feedback: (1)

Darren, I won't argue with you, since I definitely never mastered the Monokote techniques. But, I still have to look at the finished product, and airplanes covered with shiny plastic film just don't do it for me. And, that's totally a matter of personal taste. It also ties into the types of models I like. Some r/c designs can work with Monokote. Other types of models can't, or, rather, they simple look ridiculous with a shiny plastic finish. Again, that's just my opinion.

flyinrog

My Feedback: (1)

Never tried dope and "rates and such and I hate covering, but I have noticed that I do get better each time I use it. wings scare me the most, anybody can do a flat surface, and my iron tends to drift up in temp, always wipe the iron over an apron before I touch the plastic because the lower temp keeps it from bunching up...Rog

Andrew

CP -

No argument here about the time involved. But, sometimes it's not the speed of finishing up, it's the trip getting there. It comes back to what each of us looks for in the hobby. I've tried most of the covering products - monokote, econocoat, doculam, fiberglass, packing tape, silkspan, silk, tissue -- heck, I even picked up a roll of cellophane after your thread on light, cheap and quick.

However, the finish that I like the most is silk and dope. It ain't quick; it takes a lot of prep work; if you don't like it, it can be smelly - but some planes just look good in silk. I haven't covered with habotai from Silk Connection or Thai Silks yet, but it is high on the list.

Covering is a little like the lecky/slimer discussion -- one is not necessarily better than another, they just meet different needs.

andrew

rainedave

My Feedback: (1)

Thank you, Andrew. Very well put. And since my own life is peppered with failures and things I never finished I choose to relish in the old saying: "Happiness is a journey, not a destination."

combatpigg

My Feedback: (3)

ANDREW, I didn't know that silk was light enough for 1/2A projects, I always thought it was a 1/4 scale type material? As far as different methods for different folks goes, you have your Windy Urtnowsky types who are happy to apply each layer of dope to his Concourd D'elegance type models with 3 weeks drying time between coats and then you have your Hackers [like me] who realize that every plane in the barn is just one more flight away from getting tossed into the burn barrel. I used to go the tissue and dope route but usually found that after a hard day at the field half of the dope finish was on the cleaning rag and there were almost always holes to patch in the silkspan. Monokote is [as you already know] a break through in practicality that the masses swarmed to. Not every award winning plane at a model show is painted tissue, there have been some wizards with film who could pull off a winning effort.
The way that signs and graphics are done on commercial trucks nowadays isn't much different than a monokote job, they can pull the film around body contour lines and do some amazing work in a short time. Anyway [for those who are interested in using film], the key to success with film is heat control and working the whole area to be covered in stages
RD, that's a nice way of looking at life.

eroc144

My Feedback: (1)

In my younger days I was all about the speed of monokote, but now I'm definitely in the "journey not destination" crew. Covering and finishing a plane can be a zen thing and I'll spend days priming, filling and sanding before getting out the dope (drives my Wife crazy - "Are you sanding that thing AGAIN? You're just going to crash it anyway..." ). I'm finishing a Simple Series Cub right now and used epoxy resin over the entire plane as a fuel-proof base for the finish. I've been having a blast with automotive fillers and sanding it down to a glass-smooth finish, and can't wait to spray it with dope / retarder for that final killer glossy finish. Granted, it may only look perfect for the first few flights but man those first few flights will look GREAT!

I stopped using silkspan on 1/2a planes a while back because of the constant patching from the field and car abuse, but the comments about not using Koverall on 1/2a surprise me. I did my last DNU with Koverall and it came in at 12oz RTF. Now I ended up putting an additional 2oz of paint on it with an over-the-top ME109 scheme, but had I stopped before the obsessive-compulsive bug bit me...

EG

Andrew

CP --

[link=http://www.wattflyer.com/forums/showthread.php?t=10443]Here's a link [/link] to another forum with relative weights of coverings. I can't vouch for the accuracy, but probably they are close to correct. Light silk with sprayed dope is one of the lighter coverings, but it can be pretty fragil.

You're correct in that monokote is likely the most durable of the intermediate finishes and holds up better than tissue or silkspan, especially when landing without gear. I'm really not criticizing monokote itself, just that I'm not very pleased with my ability to apply it well and I like fooling with older dope/silk/silkspan methods.

Sneasle

there is a thread floating around somewhere where a guys gives a stepby step on how to make a flag with the plastic coverings... very nice outcome. It would take a wizz with an airbrush and alot of paint to pull that off on silk.

Granted, I am a fan for tissue, silk and dopes, but I do use the plastics alot. They aren't too too bad, just have to get used to them. It does take some patience, and it is much easier with a more acurate and expensive coering iron. Also, heat guns are your friend.

Also, I find that the transparent coverings are some of the easiest to use since they require such lower temps. They go on nice and easy and wont break your frame when they shrink.

hogflyer

I think that flag covering was probably done by RCKen. I looked for the thread but couldn't find it, but can PM Ken for the link if anybody wants the thread. He describes how to use Windex to apply the multiple colors after the base color down.

Here's a couple of guides put together by Minnflyer on Monokote covering.

Minnflyer Covering how-to
Minnflyer Covering video, part 1
Minnflyer Covering video. part 2
Minnflyer Covering video, part 3

covering videos
http://www.rcuniverse.com/magazine/a...article_id=726

Hogflyer

ptulmer

My Feedback: (5)

The Flag thread was done by a 3D'er. Ken would almost certainly know the exact thread, but IIRC they guys name was "Termigator" or something like it.