Page 5 of 15

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Wed Dec 13, 2017 9:45 pm
by AV8R Paul
All of the ribs bonded into place on the Co-Pilots side. I’ve left the one rib in the Horizontal Stabilizer by the bushings for the Stabilizer Cables out. I’ll put that one on after Chris Welds in the new bushings. Next I’ll build the hinge interface fairings, then on to the Vertical Stabilizer and the Rudder. I already have the model of the Vertical Stabilizer and the Rudder done so it is a matter of printing out the templates and modifying them as required.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 1:41 pm
by moving2time
Has anyone seen a Highlander with the wing fabric stitched instead of riveted? Never liked the way the rivets look on the wings myself but it seems that everyone is using them. Plus, I always felt that there was not a whole lot of material in the top and bottom flange of the Highlander ribs and the rivets are putting a lot of holes in those ribs. Clearly they work and hold up but I was thinking of stitching them instead. Everything I have read about the Oratex says that the glue is strong enough that stitching is not required. I would really like to use Oratex because it is nearly indestructible but I really don't like the translucency. Plus I would like to have something more that a solid paint scheme. Joe B

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 2:00 pm
by alan
I got this from my Kitfox II build manual. The covering portion was written by someone far better at technical writing than anyone I've ever seen.

Cut your wing Polyfiber pieces to size. Move them aside. Mix some Polytac and Polybrush 50/50. Brush 2 coats of this glue on all rib caps and perimeter areas. Allow to fully dry, about 1/2 hour. Lay the precut fabric piece in place, removing all wrinkles. Using a 1" disposable paint brush wet the fabric with MEK just enough to also wet the painted on glue. Make sure to keep the wrinkles out and keep the fabric fairly taut. Too much MEK will brush away some glue so don't do that. Use this 50/50 mixture when attaching your reinforcing tapes. Also, I can't stress enough to pay close attention to using a calibrated iron at the proper temperature for both tightening stages and be careful about ironing the tapes, especially on the bottom of the wings. Too much heat there can cause detachment.

I've covered 3 airplanes, 2 using this method, in a 35 year period, so I'm not an expert, but what I've just written made it much easier for me. Neither of these last 2 airplanes have had any fabric attachment problems.

This process only works if there are rib capstrips to which to glue the fabric.The empenage obviously has none but I've seen no issues with no stitching there.

Good luck.

Alan

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 2:35 pm
by kenryan
Joe B. -- Oratex paints beautifully if that's what you want.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 4:11 pm
by AV8R Paul
Putting paint on Oratex kind of defeats the “Light Weight” aspect of justifying the outrageous cost of using Oratex. If I used Oratex not only do I have to buy it, but then I get to waiste the Poly Fiber that comes with the kit.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 4:15 pm
by AV8R Paul
alan wrote:I got this from my Kitfox II build manual. The covering portion was written by someone far better at technical writing than anyone I've ever seen.

Cut your wing Polyfiber pieces to size. Move them aside. Mix some Polytac and Polybrush 50/50. Brush 2 coats of this glue on all rib caps and perimeter areas. Allow to fully dry, about 1/2 hour. Lay the precut fabric piece in place, removing all wrinkles. Using a 1" disposable paint brush wet the fabric with MEK just enough to also wet the painted on glue. Make sure to keep the wrinkles out and keep the fabric fairly taut. Too much MEK will brush away some glue so don't do that. Use this 50/50 mixture when attaching your reinforcing tapes. Also, I can't stress enough to pay close attention to using a calibrated iron at the proper temperature for both tightening stages and be careful about ironing the tapes, especially on the bottom of the wings. Too much heat there can cause detachment.

I've covered 3 airplanes, 2 using this method, in a 35 year period, so I'm not an expert, but what I've just written made it much easier for me. Neither of these last 2 airplanes have had any fabric attachment problems.

This process only works if there are rib capstrips to which to glue the fabric.The empenage obviously has none but I've seen no issues with no stitching there.

Good luck.

Alan


Alan

Do you have a flying tail on your Kitfox? Did you Rib Stitch your tail? I believe the ribs on a Kitfox are made using 5 MM plywood?

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 4:17 pm
by kenryan
It is not at all true that painting Oratex defeats the light weight. I believe that the heavy weight of other systems comes from all the layers of coatings, frequently applied much thicker than necessary. The Valdez winning Glacier Cub was painted Oratex. The finish was beautiful high gloss. Lars told me how much paint they used. I forget the exact amount, but I'm pretty sure it was ounces (ie less than a pound) to paint the whole airplane. Ask Lars, he will give you the exact number.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 11:03 pm
by AV8R Paul
Started the layout of the Vertical Stabilizer and Rudder Rib locations and length of ribs. I modeled the ribs & printed them out to verify the lengths. I did some minor tweaks and will verify fit tomorrow. If they are the correct lengths I will start cutting out the ribs tomorrow. The two bottom ribs will probably only be installed on the Rudder, the fuselage taper will olliviate the need for the the two leading edge ribs.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Thu Dec 14, 2017 11:11 pm
by AV8R Paul
kenryan wrote:It is not at all true that painting Oratex defeats the light weight. I believe that the heavy weight of other systems comes from all the layers of coatings, frequently applied much thicker than necessary. The Valdez winning Glacier Cub was painted Oratex. The finish was beautiful high gloss. Lars told me how much paint they used. I forget the exact amount, but I'm pretty sure it was ounces (ie less than a pound) to paint the whole airplane. Ask Lars, he will give you the exact number.


All might be true but, the cost has already reached my limit and another $4000 or $5000 is out of the question.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Fri Dec 15, 2017 12:44 am
by alan
Nope. No flying tail and no rib stitching.

Alan

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Fri Dec 15, 2017 4:15 pm
by kenryan
I'm not trying to push anyone to Oratex. It is not for everyone. All I'm trying to do is to provide accurate information. I double checked with Lars and he says that the Glacier Cub used 2.4 pounds of black paint over Oratex green.

AV8R Paul wrote:Putting paint on Oratex kind of defeats the “Light Weight” aspect of justifying the outrageous cost of using Oratex.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Fri Dec 15, 2017 11:13 pm
by AV8R Paul
Well I had a fruitful day today. I completed the modeling of the airfoils, and printed them out. I check them to verify the lengths, attached them to the plywood with contact cement, and cut out and sanded the Ribs for the Vertical Stabilizer & Rudder. Now I need to start cutting the mounting feature, & lightening holes.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Fri Dec 15, 2017 11:14 pm
by AV8R Paul
kenryan wrote:I'm not trying to push anyone to Oratex. It is not for everyone. All I'm trying to do is to provide accurate information. I double checked with Lars and he says that the Glacier Cub used 2.4 pounds of black paint over Oratex green.

AV8R Paul wrote:Putting paint on Oratex kind of defeats the “Light Weight” aspect of justifying the outrageous cost of using Oratex.

I just talked with Lars this evening, and he gave me the same 2.4 pounds to paint the Green Oratex Black. Information & time will tell. If you look at some of my earlier post you will see the paint scheme and colors I am contemplating. It will require a custom color mix. I am leaning towards the Plum Crazy Purple. I’m struggling with paying $5000 to $8000 to save 20 pounds, that cost $250 to $400 per pound. Ouch!

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Sat Dec 16, 2017 11:26 pm
by AV8R Paul
Ran into a roadblock with regards to the Ribs for the Vertical Stabilizer & Rudder. I get to remake a few of them. The spacing was off. I came home and remodeled to the new spacing. It all revolves around esthetics, so I’m going from 9 full ribs and 1 partial rib to 8 full ribs & 1 partial ribs.

Re: AV8R Paul’s SuperSTOL XL

PostPosted: Fri Dec 22, 2017 1:42 am
by AV8R Paul
I received clarification from Chris Wallen concerning the width of the fuselage at the rear of the aircraft. My NACA0008 vertical stabilizer and rudder will work just fine. In the meantime I have been working on the horizontal stabilizer brother interface for the copilot side. I have completed leading-edge cuff on the elevator and the elevator. Tomorrow I’m going to get back on the rudder and vertical stabilizer, because our weather is supposed to get very cold your North Texas cutting rehabs is not dependent on 65°.