Getting ready to cover

[kconner]

Hey Hatzers,

Looking for some input on choosing which covering system to use on my CB-1. I believe before Thanksgiving I will be ready for beadblasting and painting all the steel parts. My Cub is covered with the Airtech system and have been told it's easy to work with. I'm watching some DVD's on the Stewart system and the waterborne adhesive seems really nice to work with. I know PolyFiber is the most popular but I'm looking for a more gloss, semi-gloss finish. I've never done any fabric work and interested in the pro's and con's from those who have. Looks like the real expense on any system happens when you buy the paint.


Kevin Conner

[M Lightsey]

Hey Kevin,
What a great milestone it is when you start covering. It really makes you realize that you've got an airplane and not just a pile of parts.
I've used dope for repairs when the original part was covered with dope. I've done the same thing with AirTech when that's what was used on the original part. That being said, I won't use anything other than the Poly-Fiber system for any new projects in the shop. If a customer wanted any of those other systems used for a complete project, I'd politely refuse the project.
Dope is too inconsistent based on temperature and humidity, plus it's flamable. The all polyurethane systems require fresh air breathing systems for the entire application cycle and tend to be heavy. I've personally never seen what I consider a great looking finish from any of the water based systems. Besides that, before you think it's really safe to breath because it's water based, read the ingredients of the catalyst......
The Poly-Fiber system gives very consistent results through a wide range of temperatures and humidities. Because it's vinyl based, it won't support combustion. It's easy to repair, has a long service live and is easy to apply. The manual is great and seminars are available all over the country.
If you want a really shiny finish, you can top coat it with either AeroThane or Ranthane polyurethanes. (Gotta wear a fresh air breather for that) For a satin finish use PolyTone and buff it out if you want it shinier.
Everyone has their favorite system and reasons why they like it. I just know what I know. Over the years I've used PolyFiber on more than 20 projects and wouldn't keep using it if it weren't the best.
One last thing, don't let cost be a driver. Covering is a very small percentage of the cost of an entire project, yet it's the part of the project you look at every time you pull the plane out. Make it the best you possibly can.
Mark

[Clifford Hatz]

Hi Kevin, whatever system you use good luck covering. I personally like dope or Polyfiber, very little difference between the two as far as application goes, as far as dope being flammable, ALL covering prosesses will melt when they get hot, and will burn if saturated with gas or oil. Dope will polish out to very glossy finish some of Poly Fiber colors polish real good some don't. As far as Hipec , Airtech or Superflight systems go they are a little heavier, same with Randothane or Aerothane. As far as being easier, the hard work is the covering ,stitching and taping. All systems require that. Take your time and you will do a good job. Don't be afraid to cut the fabric off if you're not happy with it, all you lose is time, the real money is in final color coats.

[mmcgrew]

I had also never done fabric work and was considering hiring it done. A friend of mine (a Stearman restorer) asked if I had hung wall paper. I said I had and was pretty good at it. He answered with "well then - you have all the skills to do fabric work". I helped him do a Stearman wing - fabric, gluing, ironing, rib stitching, taping, poly Brush, Poly Spray. I have finished my Hatz fabric and I am very proud of the finished product. I have received numerous comments from "the old pros" on how good the fabric work is. As I worked on the project - If I did not like the out come, I tore it off and re did. Not a big deal. I am using Aerothane as the final finish. If I had to do over, I would use Ranthane. I have a great deal of experience with spray painting. In my work I have sprayed many of the Ureathanes for architectural uses. Aerothane is terrible to work with. Regardless of what Poly Fiber says. Aerothane is not easy to paint. You can do everything the same and end up with different results. I do not know why. I also have spoke with Consolidated Coatings direct. I wanted to know the specific gravity to spray at and was told they did not know - just thin by 33%. To me the specific gravity needs to be used as bench mark and is the only way to adjust for temp and humidity and get consistent results. The high gloss colors like "Tennessee Red" will not flow out and lay down - Some orange peel will show through. This is most prevalent on aluminum and not on fabric. The paint flows out well on fabric?? Who know why??? This occurs with the best Develibis guns. Since starting with Aerothane, I have talked with many restores and have heard the same problem many times. No experience with it but have been told Ranthane does not have this problem. Note also that this does not happen with the lighter colors such as gray (my Hatz is grey with red). I have probably sanded off enough red to do two more planes. Any way today I finished painting the last red aluminum cowlings - I hope.

So much for venting. Just remember that no one will do a better job on your plane than you.

Michael
N838MM

[alvinsager]

Hello Michael,
Congrats on getting as far as you have. Reading your post on the Aerothane vs Ranthane left me somewhat puzzled. Aren't they now both from the same manufacturer. I believe that the Industrial coatings from Randolph stayed with the original company.
Al

[mmcgrew]

Yes they are now from the same company. But it is my understanding they are formulated different. I wish I knew more about both. I have been told by several painters that Ranthane flows better. Maybe some one on the site can add more info.

TKS

Mike

[M Lightsey]

I'm located at Flabob right next to the factory, so I'm dealing with them every day. I brought it up at the breakfast table this morning and here's the deal.
The two polyurethane topcoat paints are formulated differently. They were developed separately and independently, although now both are made and sold by the same parent company.
The reducing ratios are simply a starting point, but either paint should be reduced as needed for flow out.
All the products are designed to be applied by amateurs and pros alike, but most amateurs don't have access to the equipment necessary to measure specific gravity. Besides reducing, there are many other variables involved. Temperature, humidity, air pressure, work orientation, fan width, gun distance, gun speed, etc.
It's a little like trying to explain every step necessary to make a good crosswind landing. You can give the basics, but it takes practice and experience. Someone telling you the manifold pressure setting they used isn't going to ensure that the next landing will be a good one. You have to adapt.
Always spray out some practice passes before pointing the gun at your work. Most guys are afraid of running the paint, so they end up putting it on too dry. For the same reason, most guys prefer the work to be flat. In other words the work is on saw horses and they're spraying down at it.
We like to hang the work and spray vertical surfaces. It's a lot easier to see, easier to reach, easier to keep debris free, easier to get good flow out and gloss, and a lot faster since you can get both sides in one session.
I've been batting around the idea of developing a 2 day hands-on workshop on painting, specifically as a follow on to the covering seminars that are available. Does that sound like something that anyone would be interested in?
Mark

[Clifford Hatz]

Mark made all good points on painting, I know the book says you'll do a better job then a guy who paints all the time, but that's just wrong. Hanging wings and tail surfaces more then doubles the speed of painting them, and it's way easier to do the edges. I'm sure you'd have alot of people at your seminars Mark, but man they are not easy to plan, put on, or handle all the phone questions after they start painting. But if you can deal with all that, and charge enough, you can help alot of people and be doing something else instead of being in the shop working all day.

[mmcgrew]

At this point there is a lot to be said about a one color airplane!!!!

Michael
N838MM

[mtaylor]

Well, while we're on the subject, let me run this by y'all. I covered and shot my Hatz with the Poly Fiber process using the Poly Tone. Wings are daytona white and came out very nice. But when I shot forest green on the fuselage, I got a finish that feels like there was grit in the paint. I wet sanded, cleaned my equipment, prepped and painted and again, grit in the finish. I filtered as I always do, used the same equiptment as on the wings. The project has been on hold for two years while I relocated to a flying community, rehabbed the house and built a hangar. This past summer I brought the project home from storage, wet sanded the fuselage and re shot the fuselage. Guess what...same thing. The grit in the paint sands out easily, so it can't be bead blast glass or sand. Now, I've ordered and received a new gallon of Poly Tone and am wondering if maybe the other can wasn't stirred well enough. I plan to take it to the local hardware store and put it in their paint shaker. I've talked to my supplier and he kinda acted like I was either making this up or I did something wrong because Poly Tone just DOESN't DO this. It never has for me, till now. I've talked to other people who have heard of other people having the same problem. I'm tired of wet sanding and painting. I should be ASSEMBLING! Besides, the Poly Fiber manual says not to get too many coats of Poly Tone on the fabric. I always try to get a good amount of paint off when I wet sand. I'm open for suggestions!