PDA

View Full Version : Poly Tone or Aero-Thane ??



southwind32
10-08-2017, 07:58 AM
I'm a long ways off from painting, but looking for comments pro or con on paint.
Thanks
Brian

avidflyer
10-08-2017, 08:08 AM
Poly tone is lighter, Aerothane shines more. better breathing protection is required with Aerothane as well. JImChuk

aviator79
10-08-2017, 08:31 AM
I don't have first hand experience, but in my own research I have found the following general consensus:

Poly-tone is easier to repair, can be sprayed wearing a cartridge respirator, and has a more vintage fabric-covered look. It can be buffed to a pleasant sheen, but not a high gloss. It also stains easier and is less resistant to solvents. (That's why it is easier to repair.)

Urethanes require a supplied air breathing system, give a "wet look" gloss, and are very resistant to stains and chemicals. They must be sanded off to make repairs. If you are willing to look at other Urethanes besides Aero-thane, you may also have a larger color palette to choose from.

FWIW, the factory-built planes are urethane coated.

Esser
10-08-2017, 08:39 AM
Urethane is hands down a tougher better product but not as forgiving on amateur application has polytone.

I painted my plane with a urethane product.

ken nougaret
10-08-2017, 02:35 PM
From my limited experience:
Urethane pros: shiny, durable
negatives: heavier, more difficult to spray, more difficult to repair, requires mixing hardener, more expensive, more toxic, susceptible to cracking.

Poly-tone pros: lightest, easy to spray, easy to repair, only mixing thinner, lower cost, dont need fresh air face mask, most flexable for fabric.
negatives: not as shiny, NOT resistant to chemicals.

I really wanted a shiny plane, like the factory built. But i couldnt bring myself to go that route. Im happy with my choice of poly-tone and with a couple coats of wax it has enough bling.

Esser
10-08-2017, 03:07 PM
susceptible to cracking

I would have to disagree with this comment. My urethane paint can be folded pinched bent over a 1/8" dowel and pulled back and forth and it won't crack. Automotive urethanes can have plastisicers added to make it "flexible" for bumpers and things. These will crack. True formulated for fabric urethane won't crack.

PaulSS
10-08-2017, 05:04 PM
Water-based paint (http://www.stewartsystems.aero/category/52/ekopoly)

I just thought I'd throw this into the equation. No solvents make the physical side of spraying and cleaning a lot more pleasant. My friend is just doing his RV8 and is very impressed with the paint. You need to use slightly different spraying techniques to solvent-based paint and it's best just to buy the kit they recommend but, having done that, it appears to work very well.

av8rps
10-08-2017, 06:59 PM
My Kitfox 4 is painted in aerothane. I've painted lots and lots of cars, boats, etc and NEVER had a problem putting down a show car finish, until aerothane. It has no fillers like car paint uses, so it is very flexible. But a ***** to paint, it runs all over the place, like painting water. Unless I was in a very high humidity area, I would use polytone and clear coat it with clear aerothane. That makes for a really nice shiney finish that is lightweight and yet easy to apply. (That is what Murle Williams has used on a couple of his award winning airplanes).

Other than that, I would use a different product, like Airtech, Stewarts, or Loehle. All of them can be applied over polyfiber base products, or over their own base (which is much easier and lighter imho).

Sorry for being so truthful. But I think I've painted my last Aerothane...there are better products.

HighWing
10-08-2017, 07:36 PM
My experience has been with Aerothane - two Model IVs. First a comment on a comment. It was suggested that Aerothane can crack. That was answered previously, but the earlier cracking comment can more accurately be applied to Polytone. Do a Google search on Polytone cracking. Then, and this is only my opinion, if you are a professional painter and spend 8 hours a day behind a spray gun for many years, then for sure have a fresh air respirator to protect your health. For me, though, the probable 4 or 5 hours total I actually spent in the booth spraying two airplanes doesn't come close to being a significant health hazard. I did use a high quality filtered respirator, but wasn't concerned with the risk. Sort of reminds me of the time when restoring an antique automobile with the dreaded asbestos brake linings. I worked with asbestos one day in my lifetime vs. Every day for 40 hears - not a problem.

PapuaPilot
10-09-2017, 06:37 AM
I talked to John McBean and he made a great suggestion. He said I should do the wing bays near the fuel tank in Aerothane so they wouldn't get fuel stains that wouldn't come out if it was Polytone.

I did my wings in Aerothane and got a few runs with the final color. I did the fuselage in Polytone for repairability in case I ever get a cut or rock hole in the fabric. I did the cowlings, doors and panels in Aerothane and have a little mismatch of the reds.

Dave S
10-09-2017, 08:22 AM
I think Phil correctly identified one of the main differences between polytone and aerothane.

I have done considerable auto lacquer and a little enamel (the old DULUX and some catalyzed auto urethane)

Polytone behaves much like lacquer - it is an solvent carried product that flashes off and dries quickly as the solvent goes away and does not polymerize - making it a product that has less of a tendency to run than enamels or catalyzed urethane; and, makes repairs easier because the paint can be dissolved later with solvent. Like lacquer - it takes some polishing to shine up the finished product

Aerothane behaves more like enamel, flashes off more slowly which increases the possibility of a run and it takes quite a while to fully react/harden to make a surface which is very resistant to solvent and solvent carried stains. The slow dry also makes for a shiny surface which does not need to be rubbed out.

I will admit that I have a couple of small runs in places they won't be noticed except by the guy that allowed them to happen:o

Left the very small run by the oil door as a reminder that I am a member of the human race when I go to fly the plane......

Esser
10-09-2017, 08:51 AM
The funny thing is I could have went super shiny. But I actually wanted a satin finish. It is slightly shinier than I hoped for but this is my fuselage in urethane.

N213RV
10-10-2017, 03:50 AM
Not to throw more noise into the equation, but I used Randolph Ranthane for my paint. I used the Polyfiber system through a base white (polybrush, polyspray, white polytone) on everything, then sprayed a Ranthane white and color coats. It is super flexible, super shiny with no buffing. Coats dark colors in 1-2 coats max. I’m not sure this picture does it justice, but you can get an idea.

av8rps
10-10-2017, 07:12 PM
After telling everyone why I'm not a huge fan of Aerothane, here are some things I do like about the Polytone product:

- Much easier to paint. Almost anyone can put down a decent paint job.
- The system is much lighter
- Polytone is much less expensive
- Much, much easier to repair if damaged

Oh, and if you like the hand rubbed dope look you will see on many high end antique airplanes, polytone if polished and waxed will closely resemble that hand rubbed dope finish. I personally like that look. But it can be a bit laborious to get that look, as well as to maintain it. So if you want a shiny but easy to maintain finish, the harder to spray and more expensive, heavier urethane systems may be more appealing.

And as I said earlier, a compromise could be to clearcoat Polytone. The downside of that option is if you are in a humid environment I'm told algae can grow between the Polytone and the clearcoat. (Btw, the clear used is the same clear sold to UV protect sailcloth material used on ultralights).

Regarding Aerothane resistance to fuel: My Kitfox is all Aerothane, and my paint has bubbled around the fuel fillers. Auto fuel also can smear Aerothane, as color comes off in the rag used to wipe dry. But maybe I just got some bad Aerothane paint (new owners had just taken over company when I purchased my paint, and I heard some stories from others about similar issues...).

Foxedemontheforum
10-11-2017, 12:36 AM
A friend who had a Kitfox at one time complained about cracking of the Polytone paint when the surface was cold ( after a flight in winter or on a cold morning). He claimed that just someone touching the paint with a warm finger tip was enough to cause star shaped crazing ( or cracking). He advised that I should put plasticizers in the paint before I spray .Any opinions and/ or advice before I put paint to the canvas?

Dave S
10-11-2017, 05:41 AM
Yup - it gets a bit cool up here at the 45th parallel north in the winter.

IMHO - if that type of cracking happened, I'd consider that the original paint was not applied correctly in accordance with polyfiber instructions; and, I wouldn't consider adding materials to the paint to fix something that should not happen if the polytone was applied correctly.

Polytone has been around for a long time; and, the manufacture pretty well has it's proper application figured out - their product and instructions are solid.:)

avidflyer
10-11-2017, 08:30 AM
Dave is in southern Mn, I live in northern Mn so we are usually 10-15 degrees colder. I've flown a lot in the winter on skis, and have never seen any cracking on the poly tone paint. From cold or anything else. I think the people making the polyfiber products know what they are doing. I wouldn't add any thing to it. JImChuk

southwind32
10-11-2017, 09:22 AM
This is interesting............anyone try this?

https://www.youtube.com/watch?v=OhlxE3EFcCQ

Esser
10-11-2017, 10:11 AM
Dave is in southern Mn, I live in northern Mn so we are usually 10-15 degrees colder. I've flown a lot in the winter on skis, and have never seen any cracking on the poly tone paint. From cold or anything else. I think the people making the polyfiber products know what they are doing. I wouldn't add any thing to it. JImChuk

I agree whole heartedly. My friend owns an industrial paint manufacturing company. They have 5 doctors that constantly improve their products and test them plus a whole floor of QA techs. They will know way more about what’s best for the product then any joe at the hangar. Polytone is literally on thousands of aircraft. It’s a good product. Also, plasticizers get harder and more brittle the older they get so you end up getting cracking by putting plasticizers in there.

Same with latex, it’s meant for walls Sure some people have had success but after spending way more money than I want to think of on my plane I want it to look half good and protect my fabric. It’s not the place to cheap out in my mind.

HighWing
10-11-2017, 11:11 AM
This thread is likely to become an opinion classic. But, please refer to your Poly-Fiber Manual. My copy was printed when I first started building in 1993 and has a chapter on Rejuvenating Poly-Tone. With caution driving this post, I found and downloaded the following this morning the most current manual:

Revision No. 21, September 2006

Appendix G:
Rejuvenating Fabric

All coatings lose their plasticizers in four
or five years. The rate at which plasticizers
leave is dependent on temperature and
humidity. Airplanes outside in Phoenix
can show signs of brittleness in 7 years.
Those in Maine may last indefinitely.
There is no hard and fast rule about when
to rejuvenate. Generally, hangared airplanes
may be ready in 15 years. Those kept outside
in 7 to 10. It really depends on the
heat and humidity, like all evaporation.
If the Poly-Tone seems brittle and small
cracks start developing, it is probably time.

Then in step one of the rejuvenation process is the following:

Disassemble the aircraft, if possible.
It’s much easier to spray on sawhorses
than upside down under wings.

Now with this information direct from Poly-Fiber, might their be reason to rethink the benefits of one color coat method over another.

Norm
10-12-2017, 06:33 AM
This is interesting............anyone try this?

https://www.youtube.com/watch?v=OhlxE3EFcCQ

Yes and no.
I have used Latex as a final coal process. On one plane I had, I used Stewarts glue to hold the fabric. The first coat was Kilz primer which fills the weave nicely. It is also sandable (very lightly) and gives a nice base. It is then possible to spray a nice coat on the fabric that has a similar look to polytone. The color seems to make a difference to the results sometimes with white giving the nicest finish. I have used Behr and Valspar and I think the Behr is the nicer of the two. I have heard good reports on other products as well. Glidden comes to mind as a good one to use. It is Experimental.