Fabric covering

Tom-D

Tom-D

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Tom-D
I'm in progress of recovering the 170's wings, facts are
the Ceconite change has been made and documented. (337) THe 170 has no maintenance manual, the 100 service manual does not apply.
I'm replacing Ceonite with Ceonite, different STC and yes I have the approval to use it.

AC43.13-1b states
d. Installation. Initial installation of polyester fabric is similar to natural fabric. The fabric is installed with as little slack as possible, considering fittings and other protru- sions. It may be sewn into an envelope, in- stalled as a blanket, or installed by cementing to the airframe with a fabric cement. Each STC may differ in the cement seam overlap, type of sewn seam, heat shrinking procedures, and temperature.

The new STC makes no reference to which method is to be used. I have elected to use envelopes which I must sew up.
Why? the envelops you buy are over $400.00, the fabric to make them is less than $250.00 for both.

So, here is the question.

all envelops I've seen use a french felt seem to sew the ceconite together to create the for and aft chord line seems.
If I change that to any other seem, is that a modification? I can't find any data that refers to this.
 
I was just looking through the Ceconite Manual yesterday and didn't see anything either.

from page 2-25 of 43.131B, seems any of the seams listed in the table are allowed.

.
Sewn Seams.
(1)
Machine-sewn seams should be
double stitched using any of the styles illus-
trated in figure 2-1 A, B, C, or D. A machine-
sewn seam used to close an envelope at a
wingtip, wing trailing edge, empennage and
control surface trailing edge, and a fuselage
longeron may be made with a single stitch
when the seam will be positioned over a
structure. (See figure 2-1 E.)
Click to expand...
 
Tom-D said:
The new STC makes no reference to which method is to be used. I have elected to use envelopes which I must sew up.
Why? the envelops you buy are over $400.00, the fabric to make them is less than $250.00 for both.
Click to expand...

Out of curiosity, why must you use an envelope? Can't you just lay down a sheet over the top, over lap the leading and trailing edges by a couple of inches and do the same thing for the bottom?
 
Greg Bockelman said:
Out of curiosity, why must you use an envelope?...
Click to expand...

You don't have to, as Tom said - he "elected" to. There are advantages and disadvantages either way that mostly involve time and money. Some people don't like envelopes, they can be awkward and troublesome if they don't fit right. By making your own you can address that issue and save some money (but not time)
 
Greg Bockelman said:
Out of curiosity, why must you use an envelope? Can't you just lay down a sheet over the top, over lap the leading and trailing edges by a couple of inches and do the same thing for the bottom?
Click to expand...

You can, it's called the blanket method.

Some buyers expect to see the envelope, thinking that is the way the factory did it. It has to do with back in the day using cotton we had warp and fill threads to orientate the fabric.

with ceconite, it doesn't matter, it is as strong one way as the other.

With the blanket method you must have a glue seem on the leading edge, not with the envelope. No glue seem makes it look smoother.
 
VanDy said:
I was just looking through the Ceconite Manual yesterday and didn't see anything either.

from page 2-25 of 43.131B, seems any of the seams listed in the table are allowed.

.
Click to expand...
That's my opinion too, but would it be FSDO's?
 
Henning said:
Why would the FSDO disagree with the manual if you use one of the listed seams?:dunno: You could ask your PMI...
Click to expand...

Application method must be supported by approved data, I can't find any.

Remember the 43-13 doesn't apply to aircraft supported by their manufacturer.

the 48 came from the factory with cotton, neither STCed up grade tell which method to use, or what seem is required.
 
Tom, I thought you liked some other fabric method.....I forget the name, not Ceconite.

Anyway, you use to recommend it. What happened???

Karl
 
kgruber said:
Tom, I thought you liked some other fabric method.....I forget the name, not Ceconite.

Anyway, you use to recommend it. What happened???

Karl
Click to expand...

Ceconite is the name of the dacron fabric. all the STCs use it.

Except the fiberglass crap that I forget the name of.

Stewart's? is that what you are thinking of? I still use it.
 
Tom-D said:
Ceconite is the name of the dacron fabric. all the STCs use it.

Except the fiberglass crap that I forget the name of.

Stewart's? is that what you are thinking of? I still use it.
Click to expand...


I think the fiberglass stuff was called Razorback
 
Customer preference, that is the name of the game when restoring, what will sell best.

so when the customer looks at the aircraft and asks " how did you get approval for that seam", you must have an answer, God forbid that question is ever asked by an accident investigator.
 
Tom-D said:
Customer preference, that is the name of the game when restoring, what will sell best.

so when the customer looks at the aircraft and asks " how did you get approval for that seam", you must have an answer, God forbid that question is ever asked by an accident investigator.
Click to expand...

Well, I guess that leaves you calling your PMI, let him figure it out.
 
You can see these seams, I can almost make them disappear but to quite.
 

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Tom-D said:
You can see these seams, I can almost make them disappear but to quite.
Click to expand...

Seems like the seams on the leading edge and trailing edge of the blankets would be more unobtrusive and less noticeable. :yes:

Would that seam be less noticeable if you could get it to lie under a rib tape?
 
Tom-D said:
Some buyers expect to see the envelope, thinking that is the way the factory did it. It has to do with back in the day using cotton we had warp and fill threads to orientate the fabric.
Click to expand...

Sigh. That MIGHT make a difference if one were to get it judged. But Holy Cow. How anal can people get? At that rate, they would want you to use cotton.
 
Greg Bockelman said:
Seems like the seams on the leading edge and trailing edge of the blankets would be more unobtrusive and less noticeable. :yes:

Would that seam be less noticeable if you could get it to lie under a rib tape?
Click to expand...

depends on a couple of things, Vne, and the chord of your wing, although, the way Tom did it is preferrerd with the seams running parallel to the chord.

Tom, hand sewn or machine?
 
Greg Bockelman said:
Seems like the seams on the leading edge and trailing edge of the blankets would be more unobtrusive and less noticeable. :yes:

Would that seam be less noticeable if you could get it to lie under a rib tape?
Click to expand...

and put the seam over an aluminum leading edge and see just how well you can really hide it :D
 
I would think that lacking any reccomendations of which seam to use in the STC, you would be good to go with AC-43.13. Isn't that the purpose of the AC? To be used when no other information is available?
The STC folks probably don't care what seam you use, and are most likely expecting the buyer to be using the blanket method anyway.
So lacking a MX manual for the airframe, and no indications in the STC. 43.13 is the next source. Follow it, and the FSDO should have no problem with it. IIRC the title of the AC is "Acceptable Methods, Techniques, and Practices.
Or call the STC holder and ask about it.
 
VanDy said:
depends on a couple of things, Vne, and the chord of your wing, although, the way Tom did it is preferrerd with the seams running parallel to the chord.

Tom, hand sewn or machine?
Click to expand...

Well, we are talking a cessna 170 here. Vne is something like 160 mph.
 
Greg Bockelman said:
I would think a glue seam would be less noticeable than the seam Tom posted a picture of.
Click to expand...

All seams have a pinked edge tape over it, they are very difficult to make disappear.

The easiest system to make that happen is Airtech. but it is expensive, and stinks, requires a thinner that is 80 bucks per gallon.

Stewarts is the cheapest, because there is no thinner needed, and cleans up with soap and water. Their ECOFIL is the base coat, but it is more of a UV blocker / primer than a filler and it is difficult to sand.

I have been unsuccessful at spraying their top coat with out fish eye.
 
Tom-D said:
All seams have a pinked edge tape over it, they are very difficult to make disappear.

The easiest system to make that happen is Airtech. but it is expensive, and stinks, requires a thinner that is 80 bucks per gallon.

Stewarts is the cheapest, because there is no thinner needed, and cleans up with soap and water. Their ECOFIL is the base coat, but it is more of a UV blocker / primer than a filler and it is difficult to sand.

I have been unsuccessful at spraying their top coat with out fish eye.
Click to expand...
What equipement are you using for the top coat?
Being waterborne, it would like clean, dry air free of any oils or other contaminates.
 
bluerooster said:
What equipement are you using for the top coat?
Being waterborne, it would like clean, dry air free of any oils or other contaminates.
Click to expand...

It's not an issue of cleanliness, it is the size of the sprayed droplets, and the dwell time between coats.

you can down load all their videos from Youtube.
 
Tom-D said:
It's not an issue of cleanliness, it is the size of the sprayed droplets, and the dwell time between coats.

you can down load all their videos from Youtube.
Click to expand...

Have you used the updated formulation they released in the last year or so? They claim it is much more user friendly.
 
kyleb said:
Have you used the updated formulation they released in the last year or so? They claim it is much more user friendly.
Click to expand...

No I have not. their color chart is very limited.
 
Tom-D said:
It's not an issue of cleanliness, it is the size of the sprayed droplets, and the dwell time between coats.

you can down load all their videos from Youtube.
Click to expand...

Watched the videos on application of their EkoPoly, and noticed two things.
#1, he's using a small fluid tip, and a high volume air nozzle.
#2, first coat is sprayed dry with multiple passes, using near max air for the nozzle. (just exactly what you want to do when fisheye is anticipated)
Then he waited untill it was just tacky, without sticking to his finger.(wasn't watching the clock) And then applied the second coat semi wet, allowing it to flow, and achieve gloss, behind the gun. (kinda like acrylic enamel)
Water and oil don't mix, Air compressors, by their very nature, impart oil into the air they compress. That oil is then transferred to the equipement plugged into the hose, and then sprayed out through the exhaust of that equipement. And only gets worse over time as the wear on the compressor continues. I have eliminated that problem by using an Accuspray model 60 and a Croix turbine. A true HVLP get-up. I've been using this system for about 12 years now, and have yet to have any contaminated air related problems. (fisheye, water droplets, etc.)
It works well with the waterborne systems, because there is no oil, the air is dry (heated), and the sheer volume of is shocking, while the pressure is very low, ~8psi. I use a 0.9mm fluid tip, with a #7 air nozzle.
 
bluerooster said:
Watched the videos on application of their EkoPoly, and noticed two things.
#1, he's using a small fluid tip, and a high volume air nozzle.
#2, first coat is sprayed dry with multiple passes, using near max air for the nozzle. (just exactly what you want to do when fisheye is anticipated)
Then he waited untill it was just tacky, without sticking to his finger.(wasn't watching the clock) And then applied the second coat semi wet, allowing it to flow, and achieve gloss, behind the gun. (kinda like acrylic enamel)
Water and oil don't mix, Air compressors, by their very nature, impart oil into the air they compress. That oil is then transferred to the equipement plugged into the hose, and then sprayed out through the exhaust of that equipement. And only gets worse over time as the wear on the compressor continues. I have eliminated that problem by using an Accuspray model 60 and a Croix turbine. A true HVLP get-up. I've been using this system for about 12 years now, and have yet to have any contaminated air related problems. (fisheye, water droplets, etc.)
It works well with the waterborne systems, because there is no oil, the air is dry (heated), and the sheer volume of is shocking, while the pressure is very low, ~8psi. I use a 0.9mm fluid tip, with a #7 air nozzle.
Click to expand...

Those videos were shot in Cahmere Wa, that is on the dry side of the state, we here on the wet side do not enjoy the drying times they do.
 
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