Fabric pros and cons.

Bravo to Oliver for his attitude in the previous post (91). I've only used Stits and Stewarts. I had some trouble with both, and in both cases I think it was my own fault. My first go-round with Stewarts I got some water bubbles. I attribute that to putting finish coats on too heavily. More recently I've had excellent results with Stewarts.

Oliver said:

My concern; one misstep can ruin an entire covering job.
That point should be hammered home to anyone ...

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Oliver, I really appreciate this comment. While I'm a total newbie in this area compared to most of the folks on this forum, I believe your statement to be absolutely TRUE about ALL of the covering systems, including painted or polished aluminum...

Trust me, I could screw up ANY of them! There's just something about painting a smooth surface that messes with my slightly OCD mind. My wife has learned this, and will not even allow me to paint lawn furniture, much less anything "important" to her.

Part of my budget for any "build" would have to be outsourcing the paint job, at least!

Zook said:

So which system is easier to fix if I get a hole or tear In it.

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I have patched many holes in the belly and the bottom and top of my horizontal stabilizer (rocks, one clear through) on my Poly-Tone covered plane with great results. Other then the final finish, but's that's probably because I brush applied 12 year old paint! But mechanically, all the patches were quick and easy to apply, and stay secure.

You can also invent your own covering system, here’s a quote from a well known aerobatic plane builder:

“Many folks have asked, and continue to ask about the system I used to cover my airplane and our experimental airplanes in the shop. the new revision is as follows:

Superflite heavy fabric, it accepts the glue better than ceconite. if requested double covered with a layer of medium to first compression rib before laying down full layer. see my build thread for pics and description. round lace cord, polyfiber hidden knot. 3" tapes on ribs.

3M 30-NF Adhesive to glue fabric to airframe basically following stewarts system instructions with a few other little tricks.

Weave sealed with straight 30-NF rolled on open areas using a 6" foam paint roller. wipe off excess using blue shop towels.

PPG Delfleet Evolution Primer F3970 mixed 3:1 with F3971 Hardener and then 1/2 part F3331 Reducer and 1 part DX814 Flex Agent.

Top coat with Sherwin Williams Acryglo base clear system.”

Oliver said:

You can also invent your own covering system, here’s a quote from a well known aerobatic plane builder:

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Only if your airplane is licensed in a non certified category. Also remember Steve Wittman died when his self designed fabric system departed the airplane in flight.

I wonder why the round cord? The rest sounds a bit like Airtec. I bet he uses external breathing air.

bob turner said:

I wonder why the round cord? The rest sounds a bit like Airtec. I bet he uses external breathing air.

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Granted, this guy is building/maintaining exp planes used in hard acro competition and subject to high hp prop blast.
To Skywagons point: yes, experimental. Any deviation in an STC’d covering process used on certified planes voids the STC.

Re round vs flat cord, same guy:

“A note about rib stitching or rib lacing as polyfiber likes to call it now. We use the standard 43.13 knots above the fabric tying method with round cord. Place the knots on the bottom of lower stuff and tail, top of upper parts and right side of vertical parts (unless it is a cub, champ, Bird biplane then use left of vertical). I have done many tests on cord and knots. The above the surface knot is always tighter than the hidden one because the connector string is an important part is the lacing system and it is usually loose in the hidden knot method. The hidden one is not needed as the string is small unlike the huge string used in WWII on staggerwings where the hidden knot was developed. Most people can't find the knots on the jobs we do here. We don't use flat cord for 2 reasons. First, it is a pain in the neck to keep from having twists in it and second is that it is only 2/3rds as strong as round! Yep flatter is weaker!”

Oliver said:

Re round vs flat cord, same guy:

The hidden one is not needed as the string is small unlike the huge string used in WWII on staggerwings where the hidden knot was developed. Most people can't find the knots on the jobs we do here. We don't use flat cord for 2 reasons. First, it is a pain in the neck to keep from having twists in it and second is that it is only 2/3rds as strong as round! Yep flatter is weaker!”

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As long as the cord is stronger than the original cotton cord, it's strong enough for me. I used the flat cord on my latest job and liked it. I was able to minimize the bump with it. Yes it is a little more effort to keep the twists out, but is worth it. A technique is developed. I buried the twist inside the wing, rather easy really. Also I tried the "Staggerwing knot" and had no trouble keeping the connector string taught. I would use the flat chord and "Staggerwing knot" again.

I’m not advocating any of the above - creating your own system, round vs flat etc..
Interesting to what others have done/are doing. Take away wherever you wish.

I have been very fortunate and had the opportunity to watch two master coverers at work.
Lots of tips and tricks are developed over time, some good some not so good.
I have also had the opportunity to strip fabric from wrecked planes. I am pretty methodic as I go, always interesting to study how others have tackled tricky areas when glueing, taping etc..
Also areas that have failed during the life of the plane.
One can also learn a lot from studying finished work up close, say at a fly in. Personally, I’m always drawn to two areas when observing a finished plane, fuselage where it meets vert stab and wing tip bows. One can tell a lot about builder from how neatly they’ve tackled these areas.

It would be fun to start another thread dedicated to covering, tip, tricks.
Most systems begin with adhering fabric as a foundation. It’s usually here where cosmetic and structural errors can be addressed and avoided.

Doug

Oliver said:

John,

Im an ol dog new trick guy and, by nature, suspicious of anything new. Especially something that involves mixing water with paint ;-)
Happy Thanksgiving!
Doug

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Doug, thank you. Anytime you're ready to try a "new trick", I'd be honored to be the one to help you! Come on out here and stay a few days and I'd be glad to walk you through it!!
John

cubdrvr said:

Doesn't anyone use AirTech?

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If I was going to use a solvent borne system, that's most likely the one I'd head to.
John

John,
Thank you,
very generous offer, love to meet some time!
doug

I did not know you could still get the skinny round cord from PolyFiber. That is what I used in 1969 through about 1980.
The stuff I got in 2003 was thicker.

I just did a wing using flat, and the "palm tree/island" Stits trick, and really liked it. Did not pay attention to twist, and not one stitch had a twist showing.

The wing I repaired had been done that way, and all was nice and tight before I cut them loose. I am sold.
I am not at all sure the string connecting stitches adds any more strength than the reinforcing tape.

On that reinforcing tape, I had a really difficult time with the newer polyester stuff, until I discovered - once it is stuck on straight, you need to dope it and let the dope (Poly Brush) dry before attempting any hole-poking or stitching.

cubdrvr said:

Doesn't anyone use AirTech? I've done a couple cubs and Pawnee's with that stuff and no issues. Prime, paint, and done. Minimal to no sanding. My current cub was covered in 2000
and looks like new.....and you can clean it with MEK if you want.

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I too have done a couple of Cubs in Airtech. I really like the glue, and the primer sands very nice (can be wet sanded). Topcoat is very durable, and high gloss. Acetone based which is MUCH less toxic than MEK.
Acetone MSDS is one page. MEK MSDS is something like 17 pages.

Here are some thoughts from an earlier post https://www.supercub.org/forum/show...g-a-Javron-Cub&p=580725&viewfull=1#post580725

I like Airtech.....just my opinion..... but certainly worth a look I think

Bill

I used Airtech on three different airplanes, it looks good easy to use (that's the good). Here is the bad, over time it will crack, especially over hard surfaces such as places you might push on an airplane. Maybe it has gotten more flex agent over the years but the airplane I did 20 years, then 16 years then 12 years ago all had the same problem after about 5-6 years and all my airplanes lived in hangers. Pretty easy life on my airplane but if you push on a horizontal etc. expect it to crack, have a rock hit the bottom of the H.S. expect a big ring worm looking thing. I went with Polyfiber on Bushwacker this last time but did not like all the steps to get to paint. I went with Superflight on the newest cub I just finished, I feel like it was pretty much the same process as AirTech, will see how it holds up over time.

I'm surprised that there are many references to Stitts but only one or two of Ceconite. I'm far from being any kind of expert on fabric, but that means I like simple. With the Ceconite system you glue the fabric on, brush on nitrate, then spray on silver and color butyrate dope.

Web

I think the Airtech top coat is catalyzed urethane, and needs to be sprayed with external air to your nose.

The topcoat is gorgeous when sprayed by pros, which is what we did, over Poly Tone white (legally). Pros are very expensive - the landing gear alone, completely covered and sanded, was $1600 (they charged shop rates for drying time). We chose a more reasonable shop for one wing and spots on the fuselage. $4500, and they made no attempt to blend.

But the airplane turned out well.

Maulguy (Greg)
I agree with what you have said. Airtech is a high solids system. If you apply it per the instructions it can be thick and lack flexibility. After several years it can become brittle. The instructions recommend 3 coats of primer and three coats of topcoat. A "coat" is left to right then up and down. This is sometimes referred to a cross coat.
It is effectively two passes per "coat". (I know you know all this....it is for those who may not have your experience)

I applied 1.5 coats of primer (one crosscoat plus one more pass) and then sanded that primer pretty aggressively. I then used one coat of topcoat. Put one pass on (say the up and down pattern) wait about 15 or 20 minutes for that to get tacky, then one more (pretty heavy) pass (say left to right) and that is all. So 1.5 coats of primer and one coat of paint. That keeps it much thinner and I have not seen the cracking issues you have seen.

The downside to this is the finish it not quite as stunning as can be achieved by using more primer and paint, and there is the possibility that the primer will be too thin over the glue area and the topcoat will bleed through the primer, reactivate the glue and cause small pinholes. I believe there are pictures and more info on my thread "Building a Javron Cub".

All that said I am very pleased with the finish on my Cub. There are certainly nicer cubs with better paint jobs but I am happy with mine. Most folks are quite surprised when I tell them it only has one coat of paint.

Hope this helps

Bill

Bill,
in this system what blocks the UV from getting to the fabric?

UV protection is in the primer. If you are going to be tied down outside year round you might want to go with more primer. The reality is, at least in the lower 48, these airplanes don’t spend very much time outside in the sun. We fly them and we stick them back in the hanger. Just my opinion, but under the circumstances I think the UV protection is not that big of a deal. However, if you are outside in Alaska year round, or anywhere else tied down year round outside, then UV protection is more important.

Just my opinion and all that

Bill

jimboflying said:

Bill,
in this system what blocks the UV from getting to the fabric?

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sortve a good article all the way through for the original poster. http://www.overallaircraft.com/Article%201%20page%205%20Ceconite%20Systems.htm

So I talked to the mechanic next door to our hanger. He rebuilt a plane for himself and used dope. He would recommend we do that. It can be brushed or sprayed. It does sound like a fairly simple system. Any Comments?

All that said I am very pleased with the finish on my Cub. There are certainly nicer cubs with better paint jobs but I am happy with mine. Most folks are quite surprised when I tell them it only has one coat of paint.

Hope this helps

Bill[/QUOTE]

I did mine just as you did Bill..........keeps it lighter.....and the process is bulletproof. Not sure how it would stand up
years outside.......mine is hangared........and hate to say more now than it used to be.

Been reading through the thread; here's my $.02. I've been teaching covering and painting for Stewarts Systems now for about 4 year, very limited experience with the other systems. Every system out there will give you a great finish; all have a learning curve. There are pros and cons with every system. Like picking a type of aircraft to purchase, you have to determine your "mission" first. For me, it was first and foremost something I could shoot at home without the issues of chemicals. MEK was out of the equation from the start for me so that eliminated many systems out there. Painting and covering had to be done right off the kitchen, without causing an issue inside. I wanted to be able to work on fabric in the house, if possible, another consideration. It needed to be save with my grandkids around while I worked. As I looked at my needs and the systems out there, I decided to attend a three day seminar taught by Mark Williams about 5 years ago, held in N. Las Vegas. I learned and went home and practiced. Fast forward and three years later I was teaching covering at Airventure and seminars around the country. For me, the system meet my needs. Is it foolproof? Is any system? Like I said, all the systems can produce a superior finish. I'm working out of a three car garage off my kitchen. I don't have a $15,000 spray booth. My spray booth is made from pipes from a Costco carport tent, some fittings and tarps for a craft show booth, a fan from Lowes, and filters for a professional spray set up. These are all things that should be taken into consideration when deciding on what system to use. If you follow the manual for Stewart Systems, you will get a finish that will last for for the same length of the as the other systems, will be as 100LL fuel proof as any, and easy to repair. Will it work with auto gas? Good luck with auto gas and any system today; every region uses different chemicals in their fuel so who knows. I have a fabric sample that has been in 100LL for two years with no issues. The same sample batch went into auto gas in Ohio, again no issue. Another sample went into California Auto gas and it curled up like a dead bug shedding it's skin! Both were Ethanol based fuel, something I would not use in my aircraft but wanted to test. There is obviously something nasty in CA gas. Can a system be auto gas proof in all regions of the country? I doubt it. No manufacturer can test for every possible combination of chemicals in auto gas today. Stewart Systems top coat seems good regardless of the region so I paint inside of fuel bays as possible.

Whatever system you choose, it needs to meet your needs and than you are going to have to practice, make some mistakes, and than perfect your process in your shop. Here's some examples of my work, at home, and you will see how using Stewart Systems has worked for me.

Marty 57

Marty57 said:

Been reading through the thread; here's my $.02. I've been teaching covering and painting for Stewarts Systems now for about 4 year,

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remind us again, how many full planes you have covered.....

and with which processes/brands of covering systems?

and how long they have been outdoors in service again????

and how the different brands held up under use..?

mike mcs repair said:

remind us again, how many full planes you have covered.....

and with which processes/brands of covering systems?

and how long they have been outdoors in service again????

and how the different brands held up under use..?

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Working on my 4th with Stewart Systems; so that Silver Metallic wing is not the product of a lifelong professional painter. Stewart Systems aircraft have been outdoors now for 15+ years; John can better address that question. My comments are not a comparison to any other system; simply how I came to choose Stewart Systems.

Mike, remember the original question of the thread? "We are hoping to cover it this winter and was wanting some input on what you all would use for fabric and why." I think I addressed the original question pretty well. This is simply why I use Stewart Systems and is not a jab at any other system out there. I'm not sure why it's relevant to the question how many planes I've covered. I'll go up against anyone in covering if you have any questions about my abilities. If a builder here has only covered one plane, and was successful, should they not give their opinion as to what system to use?

Marty57

Zook said:

So I talked to the mechanic next door to our hanger. He rebuilt a plane for himself and used dope. He would recommend we do that. It can be brushed or sprayed. It does sound like a fairly simple system. Any Comments?

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What type of fabric did he use the dope on? Cotton, Irish Linen or Dacron and why? Who's brand of Dacron?
Which dope did he use? Nitrate or Butyrate or a combination if the two?
Did he need or use a blush remover or a retarder to prevent it from dying too quickly? High humidity makes dope blush, which needs to be corrected or it will keep working it's way to the surface.
Who's dope process did he use Ceconite's or the FAA's? https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43.13-1B_w-chg1.pdf Chapter 2.
What chemical did he use for the first stick coat? Wrong one, then the entire following layers can peel off down to the bare fabric.
Spraying dope requires a lot of coats for buildup. Most of it flies around in the air sticking to every place it lands. Brushing builds up with fewer coats but also requires a lot of sanding, if you want a smooth finish. If you don't care, skip the sanding. It's not required, though I suspect you will regret it later. You will spend as many hours wet sanding as you do applying the dope. Patching where you sanded through the fabric because you didn't notice a small bump with a screw underneath. :evil: There is a minimal sanding requirement with Stewarts in comparison.
I knew a fellow who repainted his airplane every year or so with silver house paint and a paint roller. It worked. It met the FAA's requirement of a taught, well filled finish. Some of the Ceconite processes when done, produce a not very well filled finish. These have a tendency to collect dirt between each pore of the weave.
What are the temperature and humidity conditions where this project is to be done?
Will any of the work be done at your home or all at the hangar?
Did he have any blushing issues or was he blessed?
Why did he choose dope over any other process?
Has he ever used any other processes?
Is this the only recovering job he has ever done outside of what he was taught in A&P school?
Did he use dope because he is reluctant to try a more up to date system? Some of us old timers are reluctant to change even when a system may be easier to use or better for our health.
Why did he choose dope over any other process?
What did he use to stick the fabric to the structure? It would be a shame when after you have your fabric stuck down and shrunk to have the edges lift off because of the coats of fabric filling chemical soaks through and lifts the "glue". This has happened.
Will this plane always be stored in a hangar or tied outside in the sun?
A dope finish when kept in the sun continues to shrink and dry out over time. The pigments of a dark finish gets sucked off, faded, chalked by the sun. When it has some life behind it stored outside, it often cracks around the edges or gets some ring worm cracks. Particularly when someone happens to push in the wrong place. This exposes the fabric to the elements.
Are you in an area where there is always a lot of dust in the air or bugs which like to land on the wet finish before it drys?

I know, a lot of questions. I am an old timer stuck in his ways. For my health, I chose to teach myself a new trick and went with Stewarts system after 50+ years of dope. No regrets, easy to learn and use. Less labor and fewer small issues. I hate spray painting and am not particularity good at it. Stewarts was forgiving for me. I believe it will be more durable than any dope system. When a person is learning from scratch, all the methods will have a similar learning curve. You are not wanting a process that is easy, you want a process that will last and for you to be proud of. A low maintenance process. Dope isn't low maintenance when compared to other systems. At least it isn't if you are planning to fly a lot. Don't worry about ease of repair. You can most always use duct tape to get you home.




Which ever system you end up using be certain to read and understand the instruction manual. In all the systems the working of the fabric attachment to the structure is basically the same, even though the "glues" are different.

Get ready to start laughing at questions from a first timer.

-Do Non Poly Fiber covering systems have a manual as simple and easy to follow as Poly Fiber? (If not, then they should create one. If they had one that created the same message/enviroment for covering, then they would sell more product.)

-Is it possible for a retard like me to use an MEK based system without self inflicted harm, or shortening my life span with a shop that is +100' from any other living space? I mean can I learn to use it safely, and are the safety directives easy to follow rather than laborious, and if I follow the easy simple safety directions will I live without it effecting my lifespan?

I couldn't watch the Stewart System videos. Figured they alone would shorten my life.

I too am frightened by MEK, but have sprayed Stits intermittently since 1969, not knowing it was MEK, and I am still here. Some are more susceptible.

my buddy finished painting his Stewart Cub, and I have to admit, it turned out ok. Most of it is not "wet look", but it looks good.

I like Dacron/nitrate/butyrate, using Super Seam cement. Not sure I have seen the problems alluded to two posts above.

I live with MEK and have so going on 50 years. I have a 1 gal can near where I am working and a near full 5 gallon I keep the smaller one filled off of. Back when I started working with MEK I could bring a fiver home in the trunk of my car, then I needed a pickup since it is to be carried in the open.
I wear disposable gloves, if you select the wrong material they dispose of themselves. I wear a respirator and work outdoors as much as I can. A respirator is not a dust mask or something like what one thinks will keep them safe from viruses. Wear an airsupply that draws your air from somewhere other than your workspace. Heck do not use it or any other solvents anywhere near your shop compressor inlet.
I have quite an assortment of other solvents for the many tasks I do but there are times that MEK is what is needed.

Can MEK hurt a person, Hill Yes it can. Both with short term or long term exposure.
I met a bodyman/painter in the mid 80's, he was a Lacquer guy. Never wore gloves or a mask. He had no fingernails. The decades of thinner had dissolved them.
This was the mid 80's, he was curious about my aircraft restorations and materials I use. He had a fear of Imron and other stuff we use. A friend of his, also a lacquer guy painted one car with Imron and had done the prep work with these fancy new chemicals. He stopped breathing that night and passed the next day in Great Barrington Ma. Hospital.
Location included since Sky might know of this.
To me MEK has a place in this world, but what was that line on a TV show decades back, "Be careful out there."
If you fear it, heed to your fears, they just might be right.