recover procedure

pitts12 · Post by **pitts12** » Fri Mar 09, 2007 10:10

Hello group,
7EC rebuild is to the point of recover. It has greeenhouse option (L16 glass) I have read the old posts on the fuselage and was wondering if anyone has used the blanket method (big tail) and how it should be done. Trying to avoid ugly seams.
Wings are ready also, and I would like to use the Pellon leading edge material, my question is, can you put a cemented seam over this material? If not where do you attach fabric to leading edge? (blanket method also).
Thanks, Ray Franke

Nathan K. Hammond · Post by **Nathan K. Hammond** » Fri Mar 09, 2007 23:41

Hi Ray, welcome to the forum.

You can do the blanket method on a big tail Champ and have it look pretty clean. The trick is to do the fuselage with 4 pieces of fabric; one for the bottom, 2 for the sides and tail, and 1 for the top. Then you'll only have a small seam running from the left side to the right side at the tip of the fin. And a glue seam running along the 2 upper side stringers. Even though the fabric manuals say 'no glue seams on stringers' it's approved because that’s how Aeronca did it at the factory.

Here's a pic of what I mean... You may have to save the pic and zoom in to see the seam. And the second I doctored to show the top and side pieces of fabric. Sorry I don't have a better photo.

I've never heard of "Pellon" but I assume its polyester padding for leading edges???? If so, glued seams over padding are not approved, because there is nothing solid for the first piece of fabric to glue too. You will have to have a seam somewhere if planning on using padding. There are 2 ways you can do it: several cordwise seams and try to line them up on ribs, or one span wise seam. I plan on using the latter with my wings. You can put the seam anywhere you want; some choose to run it along the bottom edge of the leading edge. Others prefer to have it on the nose of the LE, and some put the seam along the top of the LE about where the spar is. If you do the last option, the seam can't be seen while walking around the airplane.

Hope I didn't get too long winded. I tend to ramble on.......

nkh

pitts12 · Post by **pitts12** » Sat Mar 10, 2007 09:31

Thanks Nathan,
Pics were a big help, I looked at many champ fuselages, and to no surprise found many covering methods! I always liked the method you used, but was told by some that the seams at the upper stringers and the aft portion of top fabric at vertical fin have legality issues due to "not attached to a structural member"
Personally, I agree with you and plan on using that method. They only go 90 mph anyway, you could almost hold it on with Elmers!
Is there anyplace in particular to place aft seam in top fabric? This is just a cemented seam, correct?
Pellon is a synthetic fabric I have seen used to give a super smooth look to leading edges. I have seen some champ/cheifs with it and it looks pretty good. New light sport Cubs seem to all have it. Not sure I will use it as I have all new LE's anyway. Plan on hiding the seam up top, spanwise.
You, can't out long wind me after I have my morning Starbucks!
Thanks, Ray

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sat Mar 10, 2007 10:37

Ray,

Normally you can not have a glued seam on stringers, but since the factory did it that way, their process takes presidents over all fabric STC's. In other words, you're good to go.

Danger History alert....
When Aeronca was making airplanes, only Cotton and Linen were available. Both fabrics come in 60" wide rolls, unlike today’s synthetics that are 71". Do to the size of a Champ/Cub fuselage, Cotton wasn't wide enough to go from the lower longeron and reach the center line. Plus sewing envelopes was time consuming and expensive, so they would just glue 2 pieces of Cotton to a stringer.

I prefer to put the aft seam as close to the tip of the fin as possible. That way the seam is the shortest possible and is a little easier to hide. And this aft seam is a Stitched seam. Appendix "B" of the PolyFiber manual describes how it is done in great detail.

By the way, I see you handle is Pitts12. I got to fly one of those things once! WWOOOOOWWW!!! Talk about a rocket, that is one heck of an airplane. Nothing like rotating on the tail wheel and climbing out at a 60 degree angle.

nkh

pitts12 · Post by **pitts12** » Sat Mar 10, 2007 11:25

Hi Nathan,
Thanks for info. Not to sound like a mental case but, sew then shrink, correct? recovered a few Stinsons but never had to sew!
Model 12 is a unbelievable acro mount, has been the most fun flying I have ever done. If you are in GA I assume you flew with Larry King?
Well, off to take a busload of spring breakers to Cancun. At least the scenery will be good today!
Ray

MikeB · Post by **MikeB** » Sat Mar 10, 2007 16:01

I guess the other alternative is to use a envelope (big tail) with the bottom seperate. The last Champ fuselage I covered had the center seam the whole upper length of the fuselage which I didn't like, but with a green house and big tail it would be pretty short and eliminates having to sew from the stringer over. Just another idea

.

Mike

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sun Mar 11, 2007 00:22

Hey Ray, correct; sew then shrink.
I got to fly with Tim Brown in his 12. It's almost scary how much room there is in the front hole. It's probably my favorite Pitts of all, Curtis hit it square with that one.

nkh

I meant to snap a photo of the Champ's tail today, so you could see what that seam looked like. I'll try to do it on Monday.

pitts12 · Post by **pitts12** » Sun Mar 11, 2007 11:32

Hello,
I agree, Mike that it would be a short seam on a L16, but I think it would be easier to hide it going across the back. I think you will always see a seam if you look hard enough, it is just how you execute the job, some are almost invisible but then there are the butchers out there.........
I would like to see your pics Nathan, if it not to much trouble. The more detail the better. Thanks
Ray