Waxing your plane? Paint to touch up Polyfiber?

[Ray36048]

Re: Waxing your plane? Paint to touch up Polyfiber?

Polytone can only be touched up by spraying. If you have a small scratch you want to fix a brush will not work. Polytone has a very high ratio of solvent and a brush will not cover. The colors do change with time, even the white. The rejuvenator does bring back the original color fairly well. If you spray an area for touch up, add slow thinner for the first coat to “cut” into the old finish.

[3Dreaming]

Re: Waxing your plane? Paint to touch up Polyfiber?

Polytone can only be touched up by spraying. If you have a small scratch you want to fix a brush will not work. Polytone has a very high ratio of solvent and a brush will not cover. The colors do change with time, even the white. The rejuvenator does bring back the original color fairly well. If you spray an area for touch up, add slow thinner for the first coat to “cut” into the old finish.

My experience has been different with touching up with a brush.

[PA1195]

Re: Waxing your plane? Paint to touch up Polyfiber?

My latest go-to fix for localized Polytone cracks and ringworms is a good cleaning of the affected area and an overlying patch of fabric. If possible look from the inside out and if light is visible through a compromised area (crack down through covering layers to the fabric) then swooshing it all together with solvent-based covering may not glue it with a lasting cover. The problem becomes just that when the crack runs the full length of a former-stringer or control surface edge.

Two years into a fresh $35K quality Poly job and restoration my PA-11 had small cracks in the dope along every former and surface edge. Same on the PA-12-180 I owned before within 5 years, and now on my Taylorcraft plus various spots of ringworm 7 years after cover and assembly.

We're experimentally trying a few small repair spots (like inspection cover rings and ringworm) using Stewart's glue (EkoBond) over cleaned and roughened Polytone holding a Stits fabric patch and covered with Stewart's silver (EkoFil) under Stits Polytone topcoat. Some were left un-topcoated/silver to see if that mix of components is durable. The waterborne component in Stewart's makes it easy to work with a brush and cleanup. Two years later it's still holding hands.

Gary

[SpecialT]

Re: Waxing your plane? Paint to touch up Polyfiber?

Happy Old Year. I'll need to get some extra chemicals to see if it's Polytone or Aerothane. I would like to touch up some small prop wash chips in the fuse like the one pictured.

[N95334]

Re: Waxing your plane? Paint to touch up Polyfiber?

I have used AC&S Exoxy super fill the blue one to fill in cracks in fabric and then sand it smooth then paint.
I don't think this is legal but it worked for years.

[Scott]

Re: Waxing your plane? Paint to touch up Polyfiber?

Perhaps in attempt to ensure we're on the same page.... the top coat is only for appearance as opposed to the silver which is critical. Most of this has been covered but I'll try to summarize the contrast.

The objective from an airworthiness perspective, is to protect the fabric from UV exposure. Polyester fabric will last indefinitely as long as it's not exposed to UV. If not protected it deteriorates very quickly. With this in mind, the question is whether or not the "silver" aka poly spray (aluminized) coating is intack? This is where the UV protection comes from and is therefore the critical airworthiness element. If the silver is compromised in anyway, it needs to be put right ie 6 coats. Enough top coat needs to be removed to facilitate this silver repair.

A secondary (non-airworthiness) consideration is appearance, small cracks and blemishes in the top coat only may be ignored and may actually be preferable over some touch up attempts! Generally non-urathane topcoats can be touched up and "blended" using solvents/rejuvenators. Urathanes need to be sanded. In both cases it's necessary to ensure the surrounding topcoat is firmly adhered to the silver and the edges need to be feathered if your going to spray.

A very small area, with firmly attached edges can be touched up by building up topcoat with a small brush in several layers, then wet sanding it flush. Then it's like removing a scratch from a windshield.... use progressively finer grade wet paper until the tiny sanding marks can be buffed out with a fine polish. Larger repair areas can be blended in the same way. One technique, after the topcoat is sprayed, empty the paint gun and add half a cup of reducer to clean the gun but spray this mixture over the repair area and the surrounding areas. The reducer will help blend in the repair on non-urethane finishes. No effect on urethanes however.

The repairs are pretty much always going to show, because colours change with UV exposure, batch numbers, and time, and urethanes don't buff well, but an adequate result can be obtained if you're willing to put in the time. Unfortunately cracks often appear over ribs which makes for very difficult work to ensure no damage occurs to lacing, fabric and tapes.

[SpecialT]

Re: Waxing your plane? Paint to touch up Polyfiber?

Double post.

[SpecialT]

Re: Waxing your plane? Paint to touch up Polyfiber?

Well it's kind of a conundrum. You can't buy MEK in california anymore, I had two orders canceled but finally got it from aircraft spruce. MEK on a rag doesn't touch the paint on the wings, it only makes it shine. But rubbing a small patch on the belly of my plane removes a slight residue on the rag. So my questions are:

Does MEK on rag make polytone run? Or does it take some work (rubbing) to remove it? I didn't really want to try to fix a larger area by dissolving it, and I'm not sure if the fuselage top coat is different than the wings.

And how do you determine which "white" polyfiber cover is used? My white options are:

Insignia White (the first year you paint it?)
Juneau White (5 years after you paint it?)
Glacier White (after the first year you park it outside?)

The screen colors on the internet don't really reflect the true color do they? Thanks for the pointers.

[PA1195]

Re: Waxing your plane? Paint to touch up Polyfiber?

Does MEK on rag make polytone run? Or does it take some work (rubbing) to remove it? I didn't really want to try to fix a larger area by dissolving it, and I'm not sure if the fuselage top coat is different than the wings.

If Isopropyl will make Polytone run or at least soften in my experience, MEK certainly will. If you have MEK resistant cover you may have a two-part top coat like Aerothane or Ranthane. Some have even used auto finishes like Imron with flex additives. I use naphtha (white gas) to clean Polytone without dissolving it per Stit's recommendations.

Other obs: http://www.shortwingpipers.org/forum...fiber-or-dope&

Gary

[Hank Jarrett]

Re: Waxing your plane? Paint to touch up Polyfiber?

We used to use high molar MEK when I was in the Navy and it was very dangerous stuff. Could be taken up through the skin and could kill you. I haven't seen full strength MEK in years and doubt seriously it can be shipped over state lines without special handling (not the kind of handling home center paint companies or Aircraft Spruce use). The new stuff is still pretty dangerous stuff, but NOTHING like what we used to use. The old stuff could strip almost anything off anything including the skin from your hands.

Hank

[Buell Powell]

Re: Waxing your plane? Paint to touch up Polyfiber?

Well it's kind of a conundrum. You can't buy MEK in california anymore, I had two orders canceled but finally got it from aircraft spruce. MEK on a rag doesn't touch the paint on the wings, it only makes it shine. But rubbing a small patch on the belly of my plane removes a slight residue on the rag. So my questions are:

Does MEK on rag make polytone run? Or does it take some work (rubbing) to remove it? I didn't really want to try to fix a larger area by dissolving it, and I'm not sure if the fuselage top coat is different than the wings.

And how do you determine which "white" polyfiber cover is used? My white options are:

Insignia White (the first year you paint it?)
Juneau White (5 years after you paint it?)
Glacier White (after the first year you park it outside?)

The screen colors on the internet don't really reflect the true color do they? Thanks for the pointers.

If the MEK didn't take the paint right off then its for sure not Polytone. Check with Norm @ Norm Aero-San Bernardino Ca. Maybe send him a sample if you can and he could tell which paint and supply you with it and the thinner and whatever else you need.

[Buell Powell]

Re: Waxing your plane? Paint to touch up Polyfiber?

Didn't think about it earlier but I also have a Polyfiber color chip card that I can mail to you also if you want.

[SpecialT]

Re: Waxing your plane? Paint to touch up Polyfiber?

Didn't think about it earlier but I also have a Polyfiber color chip card that I can mail to you also if you want.

Thanks for the offer. I could contact polyfiber and get them to mail me one if I go that far. I'm going to use some white 'thane.' I'm waiting on my airbrush. I think it's Aero/Rand/urethane of some sort, the small whitish from rubbing with the rag is probably just normal removal from rubbing the belly, which has some oil mixed in. When I come up with a plan I will maybe do some more elaborate touch ups, my plane is more of a "flyer" as she's a bit of an ugly duckling, all the fairings have large gaps and need improved, it needs wheel pants, cowl paint... on and on.

[SpecialT]

Re: Waxing your plane? Paint to touch up Polyfiber?

I have used AC&S Exoxy super fill the blue one to fill in cracks in fabric and then sand it smooth then paint.

Do you think there is any merit in trying to mix some poly-spray/silver in with it when you "fill" the chip?