jim52519

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Hi Guys,
I am building a Ziroli 87" Steaeman. I covered the Fuselage and tail surfaces last week with F&M Stits dacron covering. The covering went well. Next I brushed no one coat of Poly Brush. Then I attached pinking tape over the ribs with Poly Brush. I then sprayed on the second coat of poly brush. when I sprayed the Poly Brush there were millions of pinholes. Every where there is a wood framework under the cloth, every Pinking tape, and many places on the open bays there are pinholes. Following F&M's instructions to the letter I next sprayed the silver(Poly Spray) on one elevator. The pinholes did not go away. Any suggestions how to fix the pinholes? What did I do wrong? This is turning into a nightmare! Help!

Jim

LesUyeda

I don't know about Stits and Poly Brush, but I do know about silk and dope, and I hear you having the same kind of problems: namely that when you spray the sealing coat(s) on, the air pressure from the gun tends to blow the paint right through the fabric, and the wood is leaching the finish off of the fabric. I will brush several coats of nitrate dope on first to fully seal the fabric, then paint silver. Wherever pinholes show up, I will go back and fill with a brush then spray again. Over the wooden structures, I paint nitrate coats until the wood is slightly glossy, then I know the porosity of the wood will not leach the following coats of dope out of the surface.

Les

bonanzadrv

My Feedback: (21)

I am just finishing my third scale cub with stits.

I have had a few pinholes and such but over all went well. I would call and ask Chip Mull.

He has always answered my questions and is a great guy!

Bill

mustang105

My Feedback: (12)

Does anyone know if the poly-spray affects radio range with antennas inside the fuse? I'm using all Spektrum radios now and would like to try Poly-fiber but am not sure about potential radio problems.

Thanks,
Chuck

Donairplane

My Feedback: (3)

Jim, I had same problem. Even sent Chip Mull a sample back for him to spray. Sprayed fine for him. Go Figure. I pulled my cover off and used some old coverite i still had. Worked fine. This is nuts, i though i was the only one that had this kinda stuff happen. Ordered new Poly brush will try a sample again and see if i can figure this out. It's odd yours and mine didn't work, but his did. Different batch maybe, I'm hopeful. Don.

jim52519

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donairplane,
I am glad to here I am not the only one that has had problems. I am going to call chip today and see if he has any advise.

mogman

Don't forget coverite is sealed with adhesive where stits is not.
I brush on the first coat of polybrush then spray on 2 coats, inspect the covering in a good light and spray another coat if necessary. It adds very little weight as most of what you spray on is solvents, which evaporate. I've done it like this on a few planes and no pinholes.
Cheers, Dave.

Donairplane

My Feedback: (3)

I still think something changed, I have painted about everything you could think of in my 60 + years and had about every problem that comes with painting. It's odd it would show up now as these materials have been around for a long time. Never had this problem before. Had a problem with sizing on coverite, washed with MEK end of story, just my .02. Don.

flyguy

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I just got done covering a 1/3 scale Pup. One possibility is that there could be sediment in the bottom of the Polybrush can. You must put a stick in the can and stir it. I found there was alot when I stired mine.

jim52519

My Feedback: (3)

I talked to Chip, and solved the pinhole problem by brushing on 2 additional coats of Poly Brush. The problem may have been partly my fault. As Flyguy suggested, There were solids in the bottom of the can. I took a 3/8 dowel and sanded the end to a flat point. I used this to scrape the fillers off the bottom of the can. With the rectangular cans it is harder to stir than a round can. If I had properly stirred the polyBrush in the first place, perhaps 2 coats would have done the trick. I now have a coat of silver on and no pinholes.

GregG7

I have also had the same problem. I used a rag saturated with MEK and smoothed out the pinholes. I then sprayed on another coat. The second coat went on with no problem. The next time I think I would wipe down the bare poly fiber fabric with MEK before I sprayed anything on it. I wondered if there was something on the surface of the fabric causing the problem, like oils from my hands.

Greg

littlebearcub

My Feedback: (4)

I acknowledge this post is 2 months old, but im going to use this covering for the first time and have 2 questions.

The poly fiber you use comes in heavy, medium, and light. Which are you suppost to use for model planes? I'm guessing its the light fabric but thinking medium couldnt hurt.

Also I'm about to order everything and cant find "poly brush" anywhere on the website? This is wierd to me.

Maybe after ordering the polyfiber manual and possibly the video I may have a little bit more information in my hands.

Thanks in advance!

SoCalSal

My Feedback: (16)

It should not effect your radio in any way. I have both my planes covered in the stuff and run Futaba's 2.4 system......never had any problems.

SoCalSal

My Feedback: (16)

Hi. I have used this system for years. Yes you will want the light fabric. I don't know what web-site you are looking at but in the F&M site look for the Stits light page. You should be able to find the polybrush there.
As far as the other posts about pin holes. I get them from time to time. Not sure of the cause. But this is how I handle them.

After applying the covering and one coat of polybrush . I then apply any rib stitching I'm going to use. I then let it dry at least 24 hours. Then one coat of polybrush sprayed on...dry 24 hours. If at this time there are any pin holes or small bubbles I sand very easy with like #320 wet/dry, not hard though. Just enough to get most of small threads off. Then one coat of color.......dry over night. Then wet sand entire surface with 320.this will remove any remaing threads and all small pin holes.
Don't woory if you get some light spots in the color coat at this time, just don't sand through fabric. Now your surface will be very very smooth and ready for the second color coat. Make sure your spray gun is not set so that the color paint comes out so heavy that it runs. Set it very very light. All you will do by spraying on color too heavy is waste a lot of expensive paint and get the runs OH NO!!! I just used less than one quart to apply the two color coats on my lower wings (116" span) and have some left over. Now after I spray on the trim paint I will use the clear coat to finish. This clear coat will give you a better gloss than if you don't use it. But that is your choise.

littlebearcub

My Feedback: (4)

What kind of compressor/airbrush setup are you guys using?

rack

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i did this aircraftt five years ago came out pin hole free , you got to use a low pres sprayer make sure all the wood has poly tac ,when your spraying it on watch how its laying on it will look wet when done right.if you try to put it on too light it wont seal . heres my tcraft i did i just did a repair this past weekend , vern

for what you are doing use solartex(natural), this is the best covering there is , use polly spray (silver) over it to seal and prime.
,it will be alot lighter

rack

My Feedback: (11)

this one i did with solar tex