My Fokker DVII Project

[Jeff Brooks]

Hi all,
just plugging away on the small parts for the last 4 days. (GAWD I miss Phil making these so all I have to do is assemble them!) I had glued the cap strip to the nose caps, and cut up the next set of webbings so I can assemble them at work.
I have also been trying to finish up on the fabric work on the elevator. I have been having some difficulty getting one spot to tighten up and loose a few wrinkles.

If you look closely at this photo, you can see the outside curve in the balance horns have a few wrinkles in them.


My other issue is the fabric tape that has been used to cover the outside seam. the fabric is bunching up at the curve. The tape currently only has one coat of dope on it, but I am wondering if I should cut the tape along the curve to keep it from bunching up.



if anyone has any insight I would welcome the help. In the mean time I think I better give Fred a call.
Jeff

[hank jarrett]

Time for the (moderately) expensive solution. Bias cut tapes. You cut the fabric on a 45 degree bias (so the weave is on the diagonal) and then you pull it around the curve it will form right down. There IS a problem with this, the final width of the tape will be different depending on how tight the curve is. Practice a little with some 2, 3 and 4" wide pieces (dry) to find how much to trim the tapes.
When I did my Taylorcraft I cut the bias fabric extra wide and actually trimmed it to the final width in place. Wasted a lot of fabric, but it came out nice and even. When you look at the other costs, wasting a little fabric isn't that much of the total, but I'm part Scott and wasting anything is very painful. You can get the tapes you already did off by just soaking in some more dope or thinner to soften the wrinkled stuff up.
Hank

[gipsymoth236k]

Jeff,

Concerning a technique for outer perimeter fabric tapes being free from wrinkles when applied, if you first clamp a ball peen hammer into a vice with the ball facing upward, take a length of fabric tape and pull it hard back and forth over the ball head. This then provides the fabric tape weave with the necessary curve ability to follow rather tight radius compound lines like the outer perimeter of aileron, elevator and rudder frames.

Regards,
Gary Sewall

[Jeff Brooks]

I called Fred today, and he described over the phone how to handle this problem. he suggested I bond one end of the tape to the start point and stretch the tape to the end point and dope it in place. then squirt water on the linen and let it shrink into place. then dope it. it worked like a charm! unfortunately, I am having computer issues and can't post picture of it yet.

[Jeff Brooks]

Hi all,
Here are the photos of the edge tape problem I encountered, and how the advice from Fred Murrin helped to solve it.
What he said to do is glue the ends of the tape at the start and end of the outer edge.


Then he said to center the tape & using dope, glue only the middle of the tape to the outside seam.


Once the dope is dry, you can spray the linen with water as it sits in the sun. It moved slow but very deliberately, kinds like a Venous Flytrap closing its pedals. You can see that the doping is used to keep the fabric in place so the shrinking doesn’t pull the tape to one side.


The fabric shrunk to a perfect fit, with no bunching. The end results were great. Once the fabric dried, you can just dope it.


I am off this morning to do more work in the spars today.

[Bookmaker]

Nice work Jeff. Good tip, even for us R/C'ers.

Dale

[hank jarrett]

Never tried that method before (but sure will in the future). Simpler and LOTS less expensive than cutting fabric on the bias.
Hank

[womenfly2]

Its an old technique used back in the days of covering models with silk and dope.

No matter how new the build, old proven techniques still work today.

Cheers,
WF2

[ProfLooney]

Looking great Jeff glad you got it all figured out finally. and though I dont build the real big stuff Thanks for showing the method cause it may help me with my models

[Nick]

Great stuff Jeff,
Thanks for posting that. Another good tip to file away for when the time comes.

Cheers, Nick