New Fabric Question

[PA!2]

I am rebuilding my PA 12 and having it done for the first and I hope the last time it is quite interesting. The guy who is doing the rebuild just put the fabric on and is applying blue dope for it's antifungal properties and then will apply silver dope for UV protection followed by a lot of sanding I am told. I was informed by someone else that this is a waste of time and just to use nitrate, no blue or silver dope. Since there is no fungus problem in AK the blue is not needed and the other stuff is a waste of time and money. Also I was told that when using the blue and silver dope the paint will not adhere as well. So my question is: Is using only "nitrate" the way to go?
Thanks
PA!2

 

[barkerlongez]

Regarding your fabric question -- I am a Stitts guy through and through -- and the process is slightly different than the Ceconite or others but basically the same. I would check, double check the manufacturers process procedures and follow them exactly. Lots of folks tend to cover the way they have always done it, and many of the fabric processes are new --- as compared to the old school. Both Stitts and Ceconite have good web sites with lots of good information. And the other fabric folks do also.

Since I am a Stitts guy, I am partial to their stuff, but they have an excellent video and procedures manual. Bottom line is always though, I would follow what the manufacturer says to do.
have fun
Mark

 

[S2D]

If I remember right, the blue dope is Randolph's nitrate dope. Don't think there is anything wrong with it if he is using that process. Don't think you want to build up the dope with Just nitrate tho. And you need some kind of silver dope for UV protection. If he is already putting the blue on, I'd just leave him alone. Unless you see him get out some automotive paint for the finish color.

 

[Guest]

Hey guys!

The 'blue dope' is Dac-proofer. It's a nitrate dope with anti-fungal and a bit of blue dye so you can see it as you work with it.

Randolph's nitrate dope with anti-fungal and a bit of dye is called Rando-proof.....and it's green.

Of course, the beloved Stits product whose purpose, like the Rando-proof and Dac-proof, is to adhere well to the raw polyester fabric is the pink stuff known as polybrush.

To PA-!2: don't be second-guessing your mechanic unless you never trusted him to begin with. Sounds to me like he's doing what he's supposed to if he's doing Ceconite.

...and yes, I'm a pro.

...and yes, I'd rather work with a product that I can see and am familiar with.

Good luck.

DMC

 

[Crash]

Ceconite Process

Most of the major shops here in Alaska that rebuild Cubs for a living (Crosswind STOL, Dan's, Holliday Air) prefer to use Ceconite. The process they mostly use is Ceconite 101 fabric attached with Super Seam or Poly Tack glue. Then a good coat of "Dac-Proofer" (a Super Flight Product) brushed on. Then tapes are layed down with clear dope. Then several coats of silver "Spray Fill" (a Super Flight product). Top coat is with either colored Buterate dope or a polyurathane paint like Aerothane or Imeron. For Bush work on wheels I like a Buterate dope finish because of it's ease of repair. For a float plane the polyurathane paints don't fade as fast or chalk up like a dope finish. When you thump my fabric it sounds tight like a drum, you don't get this with Poly Fiber or Hi Tek. Crash

P.S. The guy that told you to just use clear Nitrate and no silver dosn't know diddly about covering, stayaway from him!!!

 

[supercubc37]

Crash sums it perfectly.

Matt

 

[Guest]

Hopefully I'll be starting the recover process on my SC sometime next summer. I plan to use Stitts, but I'm hearing really good things about the new Aircraft Finishing Systems process, both from a guy locally who just rebuilt a supercub and from a post I saw on the short wing piper club board. Downside, have heard that painting can be a problem since this is a water based system, and some problems have developed. Don't know the nature of the problem.

So, does anyone here know about this new process...can you recommend it or not?

-Bob

 

[Speedo]

The water based systems I know of (Blue River process) have not enjoyed much long term success. They have been discussed earlier (although that may have been on the CubCrafters site). Consider this: Stitts has been around for years, and has a proven life span - let's say 20 years depending on paint used and wear and tear. The cost of a Stitts recover job can typically be amortized over 20 years. Does the new water based system you mention have a proven life span? What if it lasts only 5 years (1/4 the life of a Stitts cover job): is the water based system 1/4 the cost of a Stitts recover?

 

[Steve Pierce]

Blue River is no more to the best of my knowledge. Aircraft Finishing Systems is water based. I have not used it but know a few that have. The person I know that used it had problems with the colorcoat. The water evaporated to fast and the co. told him to keep spraying it while wet. I have seena couple of the finished products and wasn't impressed with the results. The advantage is that you don't have to deal with the chemicals. Draw back is the finish doesn't look as good. It is a trade-off you have to figure out for yourself. If you are in the SWPC contact Dan or Doug Stewart. They use it and have a website.

 

[R. JOHNSON]

I have a friend that just did a tri-pacer w/ the above mentioned system and he was not happy w/ the product, I think he had the same problems that Steve mentioned. personally I think it's pretty hard to beat Randolph butyrate dope, it's long lasting, durable, easy and safe to apply. And w/ a little elbow grease you can have a beautiful finish, ever see supercubc37 and wiflier's Cuby?

Ryan

 

[Steve's Aircraft (Steve)]

It seems the water based stuff (finish) cracks out pretty bad at around five years. I personally use Stits all the time now, I have covered stuff with almost all the various systems. The Ceconite process works ok, but I have a hard time believing that the highly flammable nitrate dope is sufficiantly retarded with a top coat of butyerate dope, which also tends to flame a little more than the Stits. If you are covering with cotton or linen
(my last job with that was around 25 yrs ago, some ag Stearmans) than the dopes are the stuff.
Steve

 

[StewartB]

Steve,
Which paint do you use with your Stits? I seek every opinion I can get. I'm using Stits, but haven't painted, yet.
SB

 

[Steve's Aircraft (Steve)]

SB

I stay with the Poly tone on the fabric, much easier to repair or refinish down the road. I usually use an acrylic enamel on the metal. The drawback is the difference in the 'shines'. There is a flattener for the enamels, but I have never used it. I have used Polytone on the metal, but it seems to scratch easy and does't adhere all that well. Have heard that if you shoot the Polytone into wet primer on the metal it sticks good, have not tried it to find out. One trick on the Polytone for a better shine is to shoot a coat of Poly rejuvinator right after the final coat on the Polytone. The theory is the longer it takes for the final coat to dry the shinier it gets.
Steve

 

[Gloc]

I have used the Stitts (now Polyfiber) process on 2 cubs with Polytone as the topcoat and had good results. For a bush plane I prefer the Polytone/dope topcoat for it's ease of repair.

The Aerobatic plane I have right now is Polyfiber up through silver with the final color in PPG Durethane with 1 capful of flexative added per quart of final color. This has proven to be an extremely durable and beautiful finish. I don't look forward to the time I have to match color over a repair though.

I thought nitrate dopes were pretty flammable, thats why I always chose the Polyfiber process?

 

[Guest]

The only approved Finish coat materials for Stits-Polyfiber are Polytone and Aerothane.

Any other topcoat is unapproved for a certificated aircraft covered using the Polyfiber process.

The problem with CAB Dope (Butyrate) on top of Stits undercoatings, as stated by Polyfiber, is that the CAB will shrink over its lifetime, while the undercoatings will not.

The problem with shooting automotive poly-urethanes over Stits or any other fabric, as stated by Polyfiber, is that automotive polyurethanes are high-solids materials. This means lots of silica fillers. They allow high build of the finish and a much more foolproof application than Aerothane. However, Aerothane, a LOW-solids polyurethane product, is FAR more flexible than the automotive products. Aerothane will flex instead of cracking and lifting off the fabric as auto-polyurethanes will do when applied as one would spray a car. Some have had OK results with auto-p-urethanes by spraying very few, very light coats.

I like to stick to the prescribed process, whether it's Polyfiber or Ceconite. Definitely hard to make money at this when I have to re-do stuff.

DMC

 

[Gloc]

DMC,

You are correct about the approved finishes for the Polyfiber process. The PPG Durethane I used is on an experimental.

Durethane is not an automotive paint, it was developed for the aircraft industry and is resistant to all aviation fuels and fluids. The PPG product sheet states that Durethane is flexible enough to spray over fabric as is (no flex agent) but most using it over fabric are adding the flex agent.

I have flown the Polyfiber/Durethane for the last 4 years now (to a VNE of 240) with no cracking problems. I have repeatedly dropped screwdrivers and other tools on the Durethane expecting the worst only to find I can't even see where the tool landed!

I will agree that the automotive Polyurethanes are a bad choice to put over fabric for the reasons you stated.

 

[Steve Pierce]

PPG is what a painter at Aviat told me they are using now on top of Randolph and I believe CC is using it over Poyfiber. I used to shoot Air-Tec over stits silver because it shhots better in my opinion than Aero-thane. I did a SC last winter with polytone and it came out glossy because of the cold temps and chilling the paint. I like the easy repaiability. We used to shoot dope over Stits silver because it was shinier and never had any problems. Know it doesn't jive with their STC.

 

[cubpilot2]

I notice lots of comments about the easy of repairability of polytone vs. Aerothane finishes or other enamels. Polytone finishs are very easy to repair but I have also found repairs over Aerothane finishs easy also. If you treat it just like you would with a polytone there is no problem. For small repairs just wash the damaged area with poly reducer, apply a coat of poly brush and let it dry, followed by more polybrush (larger repairs use poly tac) and then the tape or fabric, applying it just like new tapes, one or two coats of polybrush and then the poly spray (brushed on for small repairs) then the color. I have never had a repair done this way come loose and find it quicker then working with dope. Have never had polybrush "boil" up any enamel finish like dope will. Dope repairs require you to remove the enamel first which is a pain. I am personally sold on the polyfiber process and Aerothane finishes.

 

[Dano Bardwell]

ceconite vs polyfiber

I have used both processes & they both have good qualities about them. over time I have leaned to the stits process because of its lower burn rate, or it wont support a flame, once you seen a cub burn its sobering.

 

[Guest]

My plane is experitmental covered in the Stits(Polyfiber) process and painted with PPG durathane. I have a few small holes in the tailfeathers (from going through the brush) that I need to patch. I have been planning on removing the durathane (in the area of reapair) with epoxy paint remover before doing the repair. Ed states that removal might not be necessary. Think I'll try doing the repair over the paint like he suggests. The holes are on the bottom of the elevators and stab, so if it comes off it won't be too big of deal. I really like the Durathane, but it tried to kill me when I did the painting. I thought I was being careful using a freshair system, but it still made me sick. 5 years ago and I'm still not the same.

Don

 

[tristano]

imeron is too brittle to be used over fabric aircrafts

 

[Bill Rusk]

Don/Guest

You made the comment that the Durathane tried to kill you even with fresh air. That scares me a little. I worked really hard to get to where I could own and build airplanes and I'm not ready to lose my medical yet.
What would you do different now? Was it the product or your technique? I've sprayed a lot of different products but am still trying to learn how to do it safely. I'm looking to learn from those wiser than myself( which includes just about everyone). We could all benefit from your experience.

Bill

 

[Dave Calkins]

Having shot lots of polyurethane (Imron, Durethane, Aerothane, etc.) on more than just Cubs, and never having gotten sick yet, I have 3 items of advice. Maybe Don/Guest will point out mistakes or precautions he had not taken. I hope you get well soon, also. We shouldn't kill ourselves over a damn airplane finish guys.

1. Fresh air source. PERIOD. However, if you lack a good seal of your mask, you could suck fumes. And if your fresh air source isn't really fresh, well.....

2. Cover your skin to protect from contact with the spraying material. The stuff can get in your bloodstream other ways than simply breathing it.

3. Wear your fresh air and protective clothing and gloves while MIXING the product, and also while CLEANING the gun. This is most-likely where people screw themselves while using these iso-cyanate-containing products. They figure they're preparing to spray or now that the project is sprayed they're safe.

If we are lazy, and I have been at times, about protection, we'll be exposed. I recall a story of a model-airplane builder who had one small part to paint and just "spritzed" it in his basement and continued to work there for the evening. He fell over dead in 10 days. He'd have had a lot more fun flying models if he'd taken the couple of minutes to go outside or to use the protection at hand for a "larger" project. what a shame.

Be safe.

NEW TOPIC. I've had an Idea of spraying Aerothane on the top of surfaces, and maybe also the sides, but spraying Polytone on the undersides or where damage is likely. This way the tops will always be shiny. Also, the bottoms, which don't get as much sun aiding the oxidation, and which get dinged first will be easily repairable.

Anyone ever do this? The way I read the STC process for Polyfiber, this is completely legal and proper.

I'm interested in your thoughts. Thanks. DAVE

 

[supercubc37]

Would be legal Dave since both are Poly-Fiber products. Would be a slick way for repairs as you say.

Matt

 

[Guest]

Just use butyrate period.

 

[Dave Calkins]

Most recent guest, would you please give some reasons why you prefer "..butyrate, period.." ?

Many of us have used most of the systems out there.

There are plus's and negatives to each.

Come on, there must be some background to your strong preference for dope, "period". Or was that "..butyrate, period..." ?

 

[Guest]

dope period.

 

[Dave Calkins]

What kind, oh wise one?

 

[Crash]

Protection

Painting Protection: Before I even walk into my paint booth to mix the paint, this is what I do.

1) Open outside door a few inches and get exhaust fan going to give my paint boot a negitive pressure (no need to cover things outside the booth from overspray and it keeps fumes inside the booth).

2) Suit up in tyvek spray suit with hood.

3) Put on two pairs of "Thickster" blue chemical gloves, not the cheap latex surgons gloves!!!

4) Turn on fresh air pump and place it on in coming fresh air flow. I use a full face mask with tear off shields. I hook the face mask short whip hose with quick disconnect to waist belt and connect to fresh air hose.

5) Enter booth, mix, paint and clean up. If an outside glove gets to sticky or a hole in it then I stop and change the glove. Upon leaving the booth, I take off my suit and hang it away from my work area to off gas. I leave my paint booth fan on until there is no more fumes.

I worked at IBM with bad chemicals and painted all my (early) life without any protection. My pancreas and liver are about shot. Don't be stupid!!! Protect yourself so you can have fun when your project is done. Crash

P.S. If you get paint on you skin (anywhere) never and I mean NEVER clean your skin with any thinner of any kind!!!!! Soap and water or wear it off!

 

[Bill Rusk]

Crash/ others

I thought I read somewhere that the dopes never stop shrinking the fabric and that after 15 years may be the cause of warped wingtip bows and broken ribs, bent trailing edges etc. Is this only on the cotton or does it also apply to ceconite? If so that would seem to be a pretty significant negative re butyrate dope.

Thanks

Bill