# Polyfibre Aerothane and Ranthane - what's the difference?

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#### Battson

##### Well-Known Member
Practically in terms of the qualities of the resulting paint job, and difficulty to apply the paint, are there any significant differences between these two paint systems?
How much more durable are these polyurethanes compared to the one-part Polytone?

#### Kyle Boatright

##### Well-Known Member
HBA Supporter
I've asked these questions to several Polyfiber vendors and users. The consensus was that Polytone is a very easy finish coat to apply, but is easier to damage chemically (like from a fuel spill).

Between Aerothane and Ranthane, I'm told that Ranthane is easier to spray, although the difference isn't significant. Both of the polyurethane products are extremely chemically resistant.

#### TFF

##### Well-Known Member
What you have is the classic of two brands developing the same type product and then one acquires the other. When using the STC for a certified plane, you are suppose to stay with one line, but because they are under one roof now, Consolidated will do the paperwork to allow either with either system. What that really means is the company trusts either one to uphold their standards. Very tough stuff, hard to repair.

#### Battson

##### Well-Known Member
What do you mean when you say "hard to repair"? I hear that a lot.

#### TFF

##### Well-Known Member
Polytone is infinitely dissolvable in its solvent. You rip a hole in it, you can just glue the patch on and paint; with the correct products, of course. The Urethane paints are chemical resistant; pour whatever on them; they are tough. Rip a hole in it, you have to sand it back to get to the undercoat so you can make the patch stick. Sanding a flopping surface with 80 grit paper to dig the stuff off is going to be work; all the while not hurting anything else. Polytone is not as pretty but if you expect rash, it is as good as it gets with easy repairs. You are not suppose to bump your plane into anything so Aerothane/Rand. should last forever, but if hangar rash or snagging brush on an unimproved strip is the norm; you will have to work harder to repair the damage.

#### Kyle Boatright

##### Well-Known Member
HBA Supporter
What do you mean when you say "hard to repair"? I hear that a lot.
In addition to the repair issues already mentioned, it is much easier to blend in repairs using Polytone. Polytone isn't a lacquer type paint, but melts into other coats of Polytone in a way that is reminiscent of lacquer, so you can spray over a repair and leave a much less noticable repair than you (probably) can with the polyurethane paints.

#### Dan Thomas

##### Well-Known Member
The Urethane paints are chemical resistant; pour whatever on them; they are tough. Rip a hole in it, you have to sand it back to get to the undercoat so you can make the patch stick. Sanding a flopping surface with 80 grit paper to dig the stuff off is going to be work; all the while not hurting anything else.
You apply MEK to the backside of the fabric. The base coats soften and can be scraped off, taking the urethane with them. Once the fabric is bare, the repair becomes easier.

Still, Polytone is much easier to repair. No need to remove anything other than any polish the owner might have applied. Polytone is PVC: polyvinyl chloride, the stuff we know as vinyl. One of the most common plastics, used in thousands of applications.

Dan

#### Battson

##### Well-Known Member
Is there a noticeable difference in finish durability and wear between the Polytone and Aerothane lines of products?

Is the Polytone a more ugly result compared to a Polyurethane paint?

#### BBerson

##### Light Plane Philosopher
HBA Supporter
Polytone will fade and be dull and chalky in a few years if stored outside.
Urethane has a wet look that lasts for many years.(urethane can crack in cold weather, I saw this in Alaska, but the wet look holds for about 10 years)

#### Dan Thomas

##### Well-Known Member
Most urethanes will crack eventually anyway. I think the plastic itself tends to shrink. The wet look is nice and lasts a long time, and is much more resistant to staining. Poly-tone is mostly a flat finish to start with and never has any shine to speak of. It can be waxed and brought up shinier, but that can make it harder to repair, and I don't know if the wax eventually damages the topcoat.

Dan

#### Battson

##### Well-Known Member
Most urethanes will crack eventually anyway. I think the plastic itself tends to shrink. The wet look is nice and lasts a long time, and is much more resistant to staining. Poly-tone is mostly a flat finish to start with and never has any shine to speak of. It can be waxed and brought up shinier, but that can make it harder to repair, and I don't know if the wax eventually damages the topcoat.

Dan
Any that is still true for the Aerothane & Ranthane lines of Polyurethanes? Or can they usually resist cracking?

#### TFF

##### Well-Known Member
The airplane paints are 100 times better than if you try a car paint. The car paint will look great but it will crack in a couple of years on fabric. It does not matter if you add flex agents. You are not going to do better than the "thanes" on a plane for the look and life. A pampered plane will last forever. If you are flying a working plane polytone would be be better. You could always go with Stewarts.

#### Battson

##### Well-Known Member
I am certainly not going car paint...
I already have a Polyfibre base. The guys who are mixing Stewards and Polyfibre are having mixed results (pun intended) unsurprisingly!
I think I'll liken mine more to a working plane than a hanger queen, so it sounds like Polytone is the paint of choice. Which is good, as that's the conclusion I had arrived at too.

What are people's thoughts on the methods for getting it to stick to aluminium - i.e. spraying directly into wet epoxy primer?
Good, bad, difficult, no trouble?

#### BBerson

##### Light Plane Philosopher
HBA Supporter
I think butyrate dope is a good color topcoat for fabric.
Polytone won't stick to metal. Neither will dope.

Urethane will stick to both nicely.... But $200 gallon... Health issues.... Repair issues..... #### TFF ##### Well-Known Member It is very common to put car paint over polyfiber in homebuilts and it use to be legal on certified until about 10 years ago. Dont mix brands for the most part if you do Stewarts you have to be all in. The glue seems the only thing that you can mix. Champion is doing it on the new Citabrias and Decathlons. #### Battson ##### Well-Known Member Have you read a recent version of the Polyfibre manual? It preempts all those points about car paints, dope, sticking to metal, etc........ I guess I should add I am keen to stay "by the book". Cost savings or diversions from my chosen system aren't really worth the headaches of cracking, peeling, or having to redo it later - for me personally. Last edited: #### PTAirco ##### Well-Known Member Polytone won't stick to metal. . No, but you shouldn't paint metal without priming it first anyway and Polytone will stick to any primer. #### BBerson ##### Light Plane Philosopher HBA Supporter No, but you shouldn't paint metal without priming it first anyway and Polytone will stick to any primer. We painted a Taylorcraft with polytone (back around 1975 )in the airplane shop where I was an apprentice. The polytone blew off the primed metal in big pieces. Nobody in that shop ever used polytone again. Polytone looked to us like a gallon of paint thinner, slightly tinted. Maybe it's different today, but I won't be using it. Hard to change a first impression. #### Battson ##### Well-Known Member I have been told Polytone wont stick if the primer is dry beforehand or not compatible. I won't speculate about your example, mind you. The manual calls for Polytone to be applied to wet epoxy primer only, and the job needs to be finished before the primer finishes cross-linking so everything is attached to everything else properly. Using retarding chemicals in the primer to slow it down is another option they offer, in case you have a longer job on your hands which takes more than a week or so from first primer to final colour coat. The Polytone is just a vinyl product (with pigment) suspended in MEK, like all the other Polyfibre products, so it can only bond into other chemicals which are soluble. Like you say - colour and thinner in a tin... #### bmcj ##### Well-Known Member HBA Supporter Urethane will stick to both nicely.... But$200 gallon... Health issues.... Repair issues.....
I'm surprised this hasn't been emphasized. Polyeurothanes have serious health consequences and a forced fresh air respirator system and full suit must be used to prevent exposure. It's not so much a lung issue as it is a brain damage issue, and the effects are cumulative.

As for Polytone, I've used it often with no problems (including on primed metal). True, it will not give you the wet look mirror finish, but you can hand rub it to get a bit of a shine out of it. Besides, the paints that give you the mirror finish often do so at the expense of extra weight. Aside from the solvent smell of Polytone (only during application) and the utilitarian finish, I don't see any downside to the product.