How bad is this fabric?

[lamp_ak]

I am actively shopping around AK for a certified -18. The most recent one I went and looked at has some rough fabric on the tops of the wings, the bottom of the tail section, elevators and as a whole the fabric is a 4/10.

My question to the body is how many hours of flight can one reasonably expect from these wings? If kept outside with wing covers. Also are there any tricks for prolonging fabric life?

 

[Colorguns]

How about this one?

 

[Colorguns]

Seems to be good still.

 

[fishhook]

My opinion, fabric is junk and I guarantee you are in for some surprises when the fabric does come off.

 

[Dlthig]

I don't know that I've ever had fabric removed from anything and not be a little surprised.

 

[skywagon8a]

The question isn't hours of flight but rather months or years. What type of fabric is it? Do you care what it looks like? How little amount of money are you paying for it? It is clearly a negotiating item for reducing the purchase price. Look at the tubing just ahead of the tail post on the bottom longerons. Is there a pile of dirt sitting there? If yes, the tubing could be bad. If you don't care what it looks like, you could clean it up and throw some paint on it. The fabric, if it's dacron, it will last a long time. All of the current fabric processes of which that could be, are a form of dacron. Dacron is supposed to be a "lifetime" fabric. Finish on it prolongs it's life. Generally it's what is underneath which dictates redoing the covering. If it's still cotton or linen, it likely needs replacement.

You only asked about fabric. There are other places to look as well.

 

[Steve Pierce]

When was it covered and with what? There should be an FAA Form 337. Like Pete posted, it is a "lifetime" fabric but the finish and the structure underneath are not. Can you see light through the fabric from inside? If light doesn't penetrate the fabric it can look like hell and still last years.

 

[lamp_ak]

Thanks for the insights. Trying to educate myself the best I can while navigating the -18 market.

 

[AK56]

looks like ringworm in that one picture, light gets to the fabric and rots it. push on it with your fingers and see if go through. looks like getting close to recover time

 

[skywagon8a]

looks like ringworm in that one picture, light gets to the fabric and rots it. push on it with your fingers and see if go through. looks like getting close to recover time

Judging by the looks of the wing and that he doesn't appear to be concerned with how it looks, the ringworm can be covered with a piece of fabric and paint. Ringworm can be difficult to fix if you're looking for art gallery finishes. Recovering the whole wing is a major project and expense while patching is not.

 

[TRDunn]

A factual answer starts with a factual question. This thread is analogous to one throwing a bolt on the table and asking if it is airworthy. The OP states "rough fabric" and "fabric is 4/10"...based on what criterion? Two issues here; FABRIC airworthiness and FINISH airworthiness; it was never stated as to what materials the fabric and topcoat is. How can anyone wade in on an intelligent answer not knowing what they are dealing with? BTW, I would never patch ringworm. By definition the finish is embrittled (cause of ringworm) and the adhesion quality is questionable. Just alleviate the ringworm by taking down to bare fabric and build back up using the approved procedures in the system employed; my favorite being the old-fashioned Randolph process as it is so forgiving, (J3000 may be appropriate as well). This only after determining airworthiness of fabric by approved testing. I have tweaked several more years out of fabric that tested good but had embrittled Nitrate/Butyrate coating. Greg at Consolidated Aircraft Coatings is a wealth of knowledge in the two approved systems they support. I cannot speak to the other approved systems. A good ROT is, when in doubt, consult the manufacturer and have factual data to choose an appropriate course of action.
TR

 

[akwing]

I'd be more concerned about the condition of the airframe and other components when looking at the surface rust in those photos.

how to test fabric, per poly fiber:

 

[nhayes]

Any one with some pictures of some really abused PA18 still flying out there with old fabric??

 

[skywagon8a]

Any one with some pictures of some really abused PA18 still flying out there with old fabric??

 

[Steve Pierce]

1972 model PA18-150 with over 13,000 hours, recovered in 1992 so probably 7k hours on the fabric.

 

[TRDunn]

I can't speak to the "abused" request, however, my '54 A model has 52 years (455,500 hours ) on the current cover (Ceconite and Randolph Nitrate/Butyrate). Samples from 3 worst case areas on top of wing did not shear at 83#, did not go any further as my weight bucket was full. Dark green that gets damn hot sitting out all summer on floats, (well maybe that would be considered abuse). Just took the scalpel to the wings for a re-cover vice another rejuvenation. Impressive fabric. TR

 

[cubdriver2]

That Pacer that Roger Bates owned is still going in original Piper installed 1950 cotton

Glenn

 

[rsrguy3]

Ak wing nailed it with the proper test... that applies to any dacron based fabric system. The punch test does not.
I'll second Trdun's post and add this is only an option if the fabric passes the test. In addition to trdunns post, I would use rejuvenator prior to popping off and repairing the individual ringworm zones.
But before you make any commitment an absolutely thorough inspection needs to be made to the interior of the wing, the structure needs to be serviceable before you make a time/resource commitment. Specifically check all of the rib lacing.
Provided the wing structure is sound, it's possible the easiest way to address the issue would be to clean, wetsand and rejuvenate the surface... dope or polytone, then get pressure sensitive self adhesive patches from Lars at BAF. According to him oratex is approved as a repair over legacy covering systems. Use these over your ringworm areas then topcoat the whole thing with a sensible coat of ranthane or aerothane. Or just use the oratex patches for a chicken pox look.....
Also, offer accordingly as just the labor for a cover job is above 20k now, and none of this takes longeron rot into account. Check out the just a recover- not! thread I started.

 

[Steve Pierce]

I don't see any failed Dacron. My old beater Cub wore through the right upper stringer at the stabilizer. I see this more on Cubs without tapes on these stringers. Mainly what I see is finishes coming off and cracking, exposing the raw fabric. Once the fabric comes off it is like rolling dice with a lot depending on where and how an airplane was cared for. I have stuck my fingers through holes in fuselage tubing among many other scary stuff.