The Kitfox 5-7 wings have very little undercamber and it is no problem gluing the fabric down after the 350 shrink; just use some weights to hold it down while the glue sets.
The Kitfox 5-7 wings have very little undercamber and it is no problem gluing the fabric down after the 350 shrink; just use some weights to hold it down while the glue sets.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS
Looking to recover one wing from a KF 2. Using no rib stitching as in the original build do you recommend using poly brush or poly tac on the rib caps before shrinking or use mek and activate the tac or brush after shrinking. Also looking for a Bulid Manual for KF2 to buy at reasonable price. Also looking for a set of flaperons for the KF2 or someone who has the skins to build a set. Thanks
Last edited by Mpaul; 11-09-2015 at 06:26 PM.
This is from polyfiber site...
What about attaching the fabric?
>You will attach the structure using Poly-Tak cement. This means attaching it on leading and trailing edges, wing butt ends, etc. Do not use Poly-Tak to apply the fabric onto the surface of the plywood itself.
This to...
What holds the fabric to the plywood if I can't rib lace or attach it in any other way?
>As you know, the fabric must adhere to the plywood surface. This is particularly important on a lifting surface such as a wing. Poly-Brush is applied over the fabric which then penetrates through the fabric activating the Poly-Brush you have applied directly on the plywood. Be sure you brush this coat of Poly-Brush onto the fabric. After this step you follow the remaining steps in the manual.
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When it talks about attaching to plywood, it's not referring to cap strips on the ribs. Some planes have fairly large surfaces of plywood (or fiberglass) under the fabric. They are talking about how to get the fabric to adhere to those areas. Jim Chuk
Just follow the Kitfox build manual (SS7). It says to precoat the rib capstrips (after epoxy varnish) with two coats of PolyTak and let dry before applying fabric. Then after covering and shrinking to 350, activate the PolyTak underneath with MEK and it will glue the fabric down (use weights on the undercambered parts). Then apply PolyBrush, rib stitching, tapes, etc.
This is slightly different than the Polyfiber manual, but is tried and true for the later model Kitfoxes per the factory.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS
I might say that the old technique recommended in the early build manuals is also tried and true. I would suspect that of the first 2 or 3 thousand Kitfoxes built, all the wings were then covered using the technique in the Kitfox build manual - sequentially gluing the fabric to the capstrips with Polytack, then gluing the leading and trailing edges. I am always intrigued by the evolution of the build techniques. In the early manuals - at least my 1993 manual - rib lacing was listed as an option, but I suspect the vast majority of the early airplanes were not riblaced with only rare mention of pulling away of the fabric from the undercambered lower wing surface and that even with the I,II and III steeply undercambered wings.
The only thing that bothers me with the new technique is the shrinking before gluing on the bottom of the wing. As I understand it, the rationale is even shrinking across the length of the wing. Given the choice, I would prefer even gluing than even shrinking, as comments on uneven shrinking are even rarer than comments on fabric pulling away. But that is just me.
When i start to cover the wing i read both book..my is a 4 1200..1993..
So to polyfiber book to kitfox book...it is sometime confused for me..
I dont have my both book here...and when i will come back to my home in two week i will re read everything to make sure i do it right...
And to make it more hard...im not perfectly good in english...(im frenchi)
So i need to read ,traduce....and re read ..it is not easy especialy for covering.
Using Stewart System adhesive, on the bottom of my wings, I bonded fabric to the ribs then heat shrank. On the top surfaces, I heat shrank then bonded to the ribs. Instead of stitching, I used the same pop rivets that War Eagle used. I drilled the holes in the ribs for the pop rivets before covering and added a drop of crazy glue to each hole to stiffen the wood. It all worked well.
Hi guys, I'm thinking about re-covering my wings.
Has anyone the measurement of the wing ( area to be covered ) handy
length and width of the speedster wing is what I need.
Or how wide has the covering material to be for upper/lower lay-up or wrapping the wing.
Thanks
TUNA