Wing Covering

[Av8r3400]

To those of you who have decided to rib stitch your wings, did you still glue the fabric to the rib cap strips or did you let it float, only gluing to the leading and trailing edges, like a certificated fabric covered plane?

[jiott]

I followed the SS7 build manual and precoated the rib cap strips with diluted Polytak cement, then covered with fabric, then shrunk with heat, then brushed on MEK to activate the cement on the cap strips, then rib stitched. On the bottom undercambered part I only shrunk part way with heat and then activated the cement and let it dry with weight on it; then finished shrinking and rib stitched.

I think it is important to let it float while shrinking, then glue it down after it is in its final position and tension.

[jrevens]

I basically did the same thing with Oratex also - applied glue to the capstrips, but didn't activate it with heat & pressure until after the initial shrink.

[avidflyer]

With all the rain up here, I actually started recovering the second wing for my Avid yesterday. I reviewed the Poly Fibre manual a bit, and in the section near the back of the book that deals with undercambered wings, it says to not glue the top of the wing if you are going to ribstich. Of course you had to glue the bottom to keep the fabric from ballooning away from the rib when you shrink the fabric. I would imagine not glueing the top of the ribs would help the fabric to have a more even stretch overall. I have to admit though, as long as I already had the two coats of poly tac brushed on the top of the wing ribs, I glued it down. (belt and suspenders) Jim Chuk

[Av8r3400]

Thanks for the replies, gents.

[t j]

I poly brushed the bare cap strips top and bottom but did not poly tack them.

[jiott]

I also noticed that the Kitfox instructions differed from that section in the Polyfiber manual. However, John McB encouraged me to just follow the Kitfox manual since they have been doing it this way for years with good results. If you think about it, by gluing the ribs you add strength to the wings with all those independent box sections between ribs. The tensioned fabric acts like thousands of little tension cables to resist bending and twisting. Stronger than one big box section. Most modern bridge girders are built this way. By heat shrinking before gluing you get nice even fabric tension all along the wing. My 2 cents worth.

[Jfquebec]

Hi guy's...i started to cover my wing last week...so i read lot of time the covering book of kitfox and polyfiber...in polyfiber book they said never use polytak on plywood...so it is what i sctoch bright and clean all the wing...i put two coat of polybrush everywhere on the wing and the tank(i sand the tank with 220)
After i start like kitfox said,by the bottom ..under the wing ...li start to gluing all the rib capstrip from center...after leading and trailling edge...i smooth all cement place with iron at 225...and i heat shrink all the fabric at 250 ...

Top wing...
For the top wing i start to cement the leading edge with polytak....and same thing with trailing edge the two ribs at each tip...that it's...im there right now..
Ho! I started to iron all the edge...so after that(im at work for two week) i will heat shrink all the top to 250 and i will start to rib lace all the wing..and heat shrink to 300 and 350 ( i install reinforcement in trailing edge)
After that one coat of polybrush with a brush,,,reinforcing tape inpection rings,drain grommet,an other coat of polybrush and tree cross coat of polyspray..
I hope i doing that right...sometime it is confused beetween kitfox and polyfiber book...i will try to make a little video of my covering...let me know your own tip's
Jf

[jiott]

I believe the book says to heat shrink to 350 BEFORE gluing to the capstrips (except for the end ones) and before rib stitching. That's the way I did mine.

[Jfquebec]

You are right...but if you look for the undercamber wing ...they says to cement it first and make the rib lacing before 350 heat..but i do like you on the top..