Tissue Covering Techniques

[PROACE]

Would like to know about some of the many techniques of tissue covering from the experts out there and please start from prepping the balsa. I have never used tissue and dope and would like to do it kind of the correct way the first time.
Thanks,
Ace:confused:

[Bud Morrison]

Here is how I like to cover with tissue on fuel planes. I am by far no expert at tissue covering and there will prolly be other posting after me that I will get some ideas from.

First and foremost use a quality tissue. I have been using some china made tissue which is a knock off of the good Japanese tissue it is a hair heavier but not quite as heavy as the tissue that comes with many kits. There are also a few different types of Japanese tissues to choose from. Hopefully others will go into more detail farther in the thread as I forget the names of the different types of tissue.

I lightly sand my airframe to a smooth finish. Then I use a purple glue stick (Yes a purple glue stick) These are available everywhere, however I have found I prefer the 3M brand of purple glue stick. The elmers purple glue sticks do an ok job, but I have found the 3M ones seem to hold the tissue in place a lil nicer till it drys. Take the glue stick and paint it onto the airframe where ever you want your tissue to stick. Carefully lay your tissue onto the airframe smooth out. Then I take a piece of saran wrap on my finger and rub the tissue down onto the glue wherever I glued. The saran wrap keeps you from rubbing oils from your skin into the tissue! Make sure you pull out any wrinkles as you go. Careful remember this is tissue YOUR NOT PULLING MONOKOTE! The tissue will rip if you pull to hard. I have found this method to give me 100% better results than trying to dope the tissue onto the airframe.

I set it aside and let the glue dry. Then I will trim excess tissue and here is the best part. I take my trim iron or covering iron and it will iron down and glue anything that wasn't glued or didn't stick down properly.

I then shrink the tissue with a 50/50 mix of isopropyl alcohol and water. Sprayed on very lightly from one of them hair spray bottle my daughters use. They spray a real fine mist. I spray the bottle into the air let the BIG droplets drop then pass the covering through the mist.

After the covering dries and I am happy with the shrink than I take a brush and lightly brush some 50/50 thinned clear dope over all the tissue seams and let them dry. I do this just to make sure the seams don't lift when I spray the covering.

After the seams dry I then spray the covering with 2 light coats of 50/50 thinner and dope from one of them 10.00 air brushes with very low brush pressure. These light coats will stop the last coats from bleeding through the tissue. If I am going to use a colored dope I will then spray a coat of the color dope thinned 50/50 till I feel I have enough color coverage. then I will let that dry and hit it with a medium coat of 50/50 clear again to give it a shinny gloss.

There are many other methods for doing tissue. I have found this to give me the best painted shiny look finish. There are also the options of printing the tissue in ink jet printer to color and using pastel chalks to color the tissue. This is called chalking tissue and is a subject and art all its own.

I have found that in planes of 1/2a size that using iron on covering really doesn't add a mess of weight I have proved this by stripping the covering off a plane I wrecked and stripping the covering off a tissue cover plane I wrecked. While the tissue my be way lighter you add weight as you dope and color it. it will be lighter than the covering by a few grams but not a whole lot. I often end up adding weight somewhere to balance that equals the weight of covering differences. I like a tissued cover plane just for the looks of a tissue covered plane. Now on very small fragile airframes like the Guillows kits tissue covering is a must as the shrinkage of iron on covering will distort the airframe. You can even distort the airframe using tissue if your not careful.

As I stated the above is only my method of covering with tissue that I found to work for me. This may not work for you. You may find another method better suites you. I'm sure others will post other ways of covering with tissue. There is even iron on tissues type coverings out there like litespan it is already fuel proof. You do have to use balsalock or another iron on tissue adhesive but these type coverings also work quite well.

[TEM]

It also depends on what we are trying to cover here... For very small models, you can glue(tack) the tissue to a frame and preshrink it first. This way the tissue will not shrink after it's been applied so a weak frame wont get distorted. Also we can use this method to retain a more distributed tension to certain areas. And like bud said, for 1/2a rc, just go with iron on stuff. You will notice that iron on covering adds a lot of strength to a structure!
You can't beat the look of tissue on old airplanes.

Personally I use white glue to glue tissue. 1 brush to apply glue to the frame, then a second one to take off as much glue as possible so there leaves just enough stickyness and glue to hold the tissue. And you have to work FAST! I think I'm the only one that does this and it's not the best method, but I just got used to it over the years. Make sure you have SHARP blades. I prefer scalpel blades over xacto11's. But a new blade is only good for convering 1 model in covering. DON't throw it out. it's still plenty sharp for cutting anything else, just dont' want to risk tearing the tissue or resulting in a rough cut.

For very light models, I don't dope. When I do use dope, 50/50, and up to almost 30/70 (dope/thinner). Try it out for yourself and you will know what consistency to use.

On a side note, there are dope alternatives. Sig's got their own stuff(never tried though), thinned down white glue(works but not as good as dope), even some lacquers work. Dopes smelly stuff! And don't let it dry in your airbrush cause you can't get it out.

[T. Lyttle]

Compromise time: having covered with both tissue and SaggyBaggy, when it comes to 1/2A power models (including TopDawg) I spring for the 00 silkspan. It is nearly as strong as SB, and can be quite light (not as light as proper tissue) without the fragility, and is easier to apply. Unlike tissue, it is put on wet, and shrinks into shape, and warps are correctible (but not as easy as SB). Been using that stuff for 50+ years now, only failures had to do with too fragile a structure, not a likely problem with the Top Dawg.

[1705493]

Haven't covered with tissue for some time now and have been enlightened as to the newer methods being applied. I did it the traditional way, applying two coats of 50/50 dope to the airframe. A bit of sanding and then, brush and rub with finger, the tissue on to the frame. However, I've developed a sensitivity to aromatic hydrocarbons so the glue stick or even the white glue method has appeal. My concern with white glue is that it's water based and I'd worry about the wood absobing the water enough to warp the structure. Like when applying to one side, the water in the glue might cause the wood to swell and your piece gets bent, like a bow.

We used to use steam from a kettle to shrink but the spray method is certainly more energy efficient.

I wouldn't do a free-flight rubber job with it, but I've settled on Litespan for my small aircraft, 1/2A and under. The nice thing is that dope sticks to it and you can apply trim and a final clear coat. And it's WAY tougher than tissue.

I agree that an overdone tissue covering can be as heavy as SOME film but just to clarify, not all films are alike. Green transparent MonoKote is much lighter than say, flourescent green or the pearl finishes. I think that Top Flite is missing the boat by not offering a specialty light film in at least the primary colours.

In a previous life, I sold grinding wheels to the sawmill industry. One saw filer would demand one type of stone and another, a completely different grade and type. Both filers would do a perfect job in sharpening the saws. The point is that each individual will find a method that suits his skills and talents.

Proace, you might consider making up some test frames and trying different techiques.

BTW, what the %&* is SaggyBaggy :confused:

Andy

[T. Lyttle]

SaggyBaggy? An old term for plastic film when it used to lose its tension in the hot sun; haven't called it anything else for over 30 years, sorry!

[PROACE]

Is there any advantage to wetting the tissue prior to applyinng it to the airframe or is this just a dumb question?
Thanks,
Ace

[T. Lyttle]

Man, you best have either a VERY light touch, or VERY tough tissue to do that, in my experience. On rubber stuff, just put tissue on dry and shrink later, but on gas models, go to Silkspan; not much weight penalty there, and it DOES go on wet.

[Bud Morrison]

Originally posted by PROACE
Is there any advantage to wetting the tissue prior to applyinng it to the airframe or is this just a dumb question?
Thanks,
Ace

You can preshrink it by wetting it on a frame and letting it dry before you put it on if you have a fragile frame and dont want the tissue to shrink to much. I have never ever covered anything with wet tissue.

[BMatthews]

The original Jap tissue of years gone by used to almost dissolve if covered wet. But the new stuff available for the past 10 years or more through Peck Polymers and others is actuall very high in wet strength. Before I discovered UHU or the other gluesticks I used to lightly spray my tissue and cover damp just so it would stick down with the dope thinner rubbed through the tissue. But I too am learning that dope thinner is a great way to suffer for a week or two from solvent induced eczema (sp).

Now I use the glue stick and it's great. So here's my list....


Cover dry with the glue stick as adhesive. If there's wrinkles or warps you can ease the tissue by rewetting the glue stik with a little water on a finger tip and melt the stik glue to let you slide or lift the tissue.
WAIT FOR IT TO DRY FOR AT LEAST 4 HOURS. I didn't do this on one model and saw the glue stick adhesive let go as the tissue dried. Let it dry and there's little or no problem.
I just dope the two or three coats with a brush. It flows just fine but don't work it any more than you have too.

[sturmvogel]

I really love the look of tissue and it sure brings back memories. The last plane I covered with silk was a Don Srull 53" WACO and it still looks great. The problem is that it takes a bunch of dope and several coats and the dope smell lasts forever! I may like that smell but others do not (if you live in an apartment I'd sure try it on a small part first and see if anyone starts complaining. Airspan/Modelspan/Coverlite all give very "tissuelike" covering with the advantage that they're much tougher!! Whatever-as long as it's fun...

[mu2freighter]

One issue I'm not seeing here is the type of dope used. I've used the white glue method many a time with good results (though I'm overdue to give the glue stick method a try; maybe it's time to build a peanut FF for grins), shrinking it as described with a 50/50 mix of alcohol & water. Hmm..a side note...has anyone tried using the 90% isopropyl alcohol to control shrinking? 10% water content's nice and low!

With very delicate structures, though, I always pin the structure down to avoid warps (hence the 90% isopropyl question). But the dope I always use is NITRATE, not butyrate.

When I first got into building planes I just grabbed whatever color of AeroGloss I needed and went at it. I always wondered why my wings kept warping long after the dope was dry! From what I understand, butyrate just keeps shrinking..and shrinking...and so on, unless you add a plasticizer to it.

When I switched to nitrate dope all my shrinkage problems went away. Great stuff, although for glow engines you'll need to apply some sort of fuel proofing finish on top of it. Me, I do FF rubber/electric, and R/C electric, so it's not an issue. For scale planes, I airbrush the color on using Polly Scale water soluble acrylic paint, and I'm very happy with the system (see attached pic) (http://www.rcgroups.com/forums/attachment.php?s=&postid=1403844) . Now, don't bet the farm without testing it, but I think the Polly Scale paints are fuelproof once cured, and they do make both gloss and matte clear paint. If they won't do it, I'm sure there are plenty of other options, darn near anything can be used over nitrate dope, I believe.

Glenn

[Bob Chiang]

I also use glue stick to attach tissue to balsa frames and use alcohol to shrink. Instead of sealing with dope, I spray with Krylon acrylic. You can just spray a light mist to add some moisture resistance, or multiple heavier coats that result in the translucent look of a clear dope finish. The smell is much less strong than dope.

[sturmvogel]

I certainly agree about using nitrate versus butyrate dope. I am also very impressed with nitrate from Aerodyne especially. They sell both tightening and nontightening and their quality and ease of application seem yards above all others. A couple of my planes are diesel powered (really more than a couple) and, since they don't need fuel proofing, I use nitrate over modelspan. From what I've read, butyrate dope continues to shrink forever...

[harrier81]

Hi all:

I just have receibed a sort of "domestic tissue" from peck polymers that i ordered at tower hobbies, can somebody tell me the diferences between it and the japanese tissue?.

I just covered a plane an it seems to be pretty resistent, today i`ll start to add some dop but also y have krylon crystal clear so i don´t know what is better thinking about ading weight to the frame.?

[thesoarer]

has anyone ever tryed spay painting a tissued plane???

[PROACE]

Yes, but don't use as a urethane paint as it won't shrink well, I learned this the hard way with a 8 ft glider wing. I am sure there are a lot of methods out there but the one used and liked was preshrinking with 50/50 elmers white and water, light sanding, some primer, more sanding and then paint.

[Kenner-Boy]

Can anyone out there answer this for me? What causes the warp in the wood, the tissue tightening or the balsa getting wet?

[PROACE]

That is a good question. I would venture to say the tissue tightening since the wood frame really is not structurally sound until it is covered creating the monocote(sp) effect. That should be why it is easy to twist an uncovered wing panel and not so easy to twist a cover panel. I cannot say that I have ever seen balsa warped from moisture on any plane I have built.

[jim_ag3y]

I tried to get some dope for the LHS this week, and the owner told me that he will not stock the stuff because he has to pay $20.00 extra for each delivery, whether it be one bottle, or 100, because the stuff is considered to be a "dangerous chemical".

I did get some fuel proof spray-on substitute, but if I am going to try dope and tissue, I am going to have to get it from somewhere else.

I am seriously wondering, is that a problem nation-wide, or is this a "Maryland Thing"? Anybody know ?

Jim

[PROACE]

jim_ag3y, I don't think it is really that expensive for the LHS to get but the thing is the LHS is out to make money. Dope does not sell like the monokote so the LHS would lose money because the chances are they can't move enough product to cover the ground shipping costs.
I would suggest ordering your dope from Tower Hobbies, they carry the brand name Aerogloss. I have used it in the past and it works well but usually needs thinned a bit. You can use acetone from the local hardware store to clean your brushes or sprayer as long as there are not any plastic parts as acetone will eat them.

[Whizz]

Jim- You can order clear dope directly from Sig http://www.sigmfg.com/
Nitrate dope is best for adhesion and filling the tissue. Butyrate is a fuel proofer, which you don't need on a rubber model. You can top-coat nitrate with butyrate, but not the other way around. You can also get the correct thinner from Sig, although the cheaper, faster evaporating hardware store thinner is good for clean up.
Jim