Poly Tone or Aero-Thane ??

[Dave S]

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

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]

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]

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]

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]

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]

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]

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]

This is interesting............anyone try this?

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

[Esser]

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]

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.