How do i put a black "binding" tape around this? It has a 2" aluminum support that goes through it and my binding tape (sunbrella) won't do that tight of radius...need suggestions.....
You need bias binding tape to make a turn like that smoothly. If you don't have any, I'd make a facing instead.
Cut two circles of fabric with an inside diameter of 1.5" (1 inch smaller than the hole itself) and an outside diameter of 3.75" (1-1/2" inch larger than the hole). With right sides together (assuming your fabric has a right side), sew the two fabric circles together, 1/2" from the inner edge. Your seam line should be just a hair inside the vinyl hole. What I'd do to get it sized right is place the fabric under the hole and draw a line using the actual hole as a template.
Anyway, once this seam is sewn, snip the inside edge to just inside the seam line. Wouldn't hurt to sew around the thing twice just to keep it from unraveling. Snip all around maybe 1/4" apart . Turn your "ring" inside out so the snipped seam allowance is then hidden between the two layers of fabric. Fold under the outside edges 1/2" with the raw edges towards the inside, facing each other, making a finished edge on both pieces of the fabric - iron with a warm iron to keep the edges folded if necessary. Then, place the fabric ring inside your vinyl and topstitch the outer edges. You can use a stapler or double-stick tape to hold both the fabric in place while you sew.
Or, avoid the headache altogether and look for "carpet grommets" on the internet.
June
Tou said its a aluminum support is this permanate for like a top. So the hole has to have access not like a flagpole hole for access but the window has to fit around the pole with a closure below the pole ?
No, it's on the side curtain and yes it si a support for the top. from the top welting I have cut down 14" and binded both of those cut edges but then it "wraps" around a 2" "horizontal support.... need to finish and add support to the clear vinyl at that hole. make sense? Think of a straight down cut with a 2.5" circle cut out at the bottom...all that needs to be binded.
Something like that we'd usually sew a cuff or borders around the hole with a hem at the top with string. The cuff velcros together at the split and the string ties it tight. We also do a Velcro wrap instead of string like on an arm of a winter coat if the guy doesn't like string.
As june said bias binding is best
Id finnish the entire lanel ass to be then sew on a zipper beloe the support if its a long space. The cut up and sround the whole id then atraighten out the piece snd bind up the straight cut aour d the bole straighting it then down the other straing side back down. If its a short oiece below the lipe ill mske a velcro flap. Same principal as a cockpit cover that has to fit sround s bimini frame.
Just thought if this is a support brace bar for a top your windows must be on the inside of the frame i only do this or have seen this on mostly walkaround boats