Silkspan or CF

Tomorrow morning I am going to cover the flaps for the Skylark. I am trying to figure out which would be better for stiffness, Silkspan or .2oz CF matt.. Or does it make any difference?

Bob,

I covered the flaps on my Shark .45 with .2 Carbon Fiber. It's not
nearly as easy as working with silkspan which overlaps easily. Also,
I don't think that one layer of .2 is enough I sanded through mine in several spots. Two layers would be better unless the base surface of the flap is perfectly smooth already, then 1 layer may do it.

Thanks Jim,

I have some .5 oz CF that I used on the fuselage sides around the wing, so far I am OK on weight so might just use that on the flaps.

Hi Bob-

I am using the .2 oz. CF on wing leading edges and flaps as 1: It doesn't shrink noticably when doping so no sag between the ribs and 2: I think it finishes much easier than silkspan, less dope and thus less weight. I do find that you need to start sanding after the first coat, if you put on 3 or 4 coats first you will have fun getting it the way you would like it before putting on color.

>Bob,
>
>I covered the flaps on my Shark .45 with .2 Carbon Fiber.
>It's not
>nearly as easy as working with silkspan which overlaps
>easily. Also,
>I don't think that one layer of .2 is enough I sanded
>through mine in several spots. Two layers would be better
>unless the base surface of the flap is perfectly smooth
>already, then 1 layer may do it.
>
>Jim Pollock

Hi Jim,

I found out at dinner down at KOI that there are two types of CF veil. A "hard" and a "soft". I ran a check on some .2oz veil I have from two ifferent sources and the older stuff (don't know where it came from!!) is "softer" than the newer stuff. All was bought within the last year or so. The soft works a lot better around edges, especially when using nitrate.

Bill <><

I tend to think that Winfred's thought that silkspan that shrinks adds strength to the structure has a lot of bearing.

See Ya

I'd go with PolyCrylic and Carbon. If it shrinks, it will cause warps. The flaps of my '67 Excalibur warped, with dyed silkspan. Steve

Silkspan on Flaps. You don't need headachs. Done it both ways

Use the matt first with a couple subsequent coats of dope, sand ...then silkspan over them. Finish as you wish. They will be stiffer. If you are going to use dope again....save your white as a substrate rather than a finish color.

John