Outdoor Pilgrim needs Indoor Flex-Vent Opinions. Serious Vent-Pioneering in a Never Visted Area

How can Ideal-Air flex-duct used with be made "solid"?
I need to run this 6" flex-vent 14-ft. down my exterior greenhouse front wall, and backwall gables connecting to it's existing front and back gable "extension socks". I'm using (3) galvn. metal 90's on each run (h.depot). No daylight will enter. Ideal Co. does not manufacture any other components that would assist in this situation. Their flange-kit is for solid walls. Google comes up empty for a solution. Here is mine:
Water-proof casting wrap. The last time I broke something, they soaked the dry-roll in warm and wrapped fast.
Once the front and back vent hoses are in position (I'm not above using Industrial Velcro strips glued to the ext. peak-edges of each gable to sling-support those metal 90's hanging in mid-air), and I wrap them in plaster-casting, and they dry... will they help support the flex-tube structure free-standing and secured at the ground-level 90?
If I get no reaction from this post in a couple days, I'll cut and copy the text to the Greenhouse heading and bug those guys. THNX!

I tried really hard to understand what you were asking but I couldn't work it out. Try asking in your own language and we can copy paste it to a translator.

The short version: Has anyone ever made an Ideal-Air flex-pipe protected from damage by wrapping the pipe in duct-tape?
And/or 3"-4" water-base, but waterproof when set, plaster cast wrap? Blix City we go!
http://www.dickblick.com/products/blick-plaster-cloth/?clickTracking=true&wmcp=pla&wmcid=items&wmckw=34134-1800&gclid=CjwKEAjwtLO7BRDax4-I4_6G71USJAA6FjN1yc1CwOSXLcaodljPEdJYKPQFqEvG1JjUioH--vsEzBoClerw_wcB
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How much pipe wrap tape do I need to wrap a pipe?
Its a simple enough mathematical calculation, made simpler by the chart below. The first column is the nominal size of the pipe. The third, fourth and fifth columns tell you your requirements per 100 lineal feet of pipe, using a spiral wrap with both a 1" and a 50% over lap.

Be sure to note that as per common industry standards the length of the roll changes for the 6" wide tape. Double check your product before going to the jobsite as many manufacturers vary between 50 and 100 foot standards, regardless of the width.
http://www.mercotape.com/html/coverage100lf.html
Rolls of 4" x 100 ft. of (Blicks plaster) tape.
6" pipe with a 1" overlap-wrap for 100 ft. would take 7 rolls of plaster-cast bandage wrap.
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Thnx for replying MJ.

Yea, I'm a little confused at what you're asking. Are you trying to eliminate light leak from you're exhaust for light dep purposes

Yes, eliminating light-leaks due to rough-handling of the foil/black flex-tube that might happen, when dragging a light-dep cover over it twice a day. By wrapping the tube with plaster cast material, making the exterior of the tubing hard-shell, instead of a thin-laminate plastic film shell.
Blick says:
Blick’s own plaster cloth rolls of pre-shrunk cotton gauze fabric are impregnated with Plaster of Paris.

They’re simple to use; just cut and dip strips of plaster cloth in warm water, then apply it layer over layer on wire armatures, cores, and body parts (cannabis frail, flexible, vent systems maybe). When dry, Blick Plaster Cloth can be sanded, painted, and sealed. Setting times may vary.

Four, 4" × 62.5 yd rolls, equaling a total of 250 yards of 4" wide cloth. (shipping wt., 20-lbs.) - which seems to be about 30-odd ft. and will do the job on both 10' + or - sections.
(motor-scooter! ) Arriving in a week, free shipping. May need more for a second coat of plaster wrap, we'll see.They did the math - it takes 18" to make a complete round of 6" diameter. I'm creating 3-M glue-backed, velcro strap hangers on the ext. walls to help support the plaster wrapped vent tubes, but they'll be plaster-wrapped at the final elbow and firmly planted on the ground. And, Why not make 6" wire circles of wire-cloth screen, and attach them on the pipe's round exits, with two simple rig-wire "hinges" at the screen-top to keep critters out? The exit air can blow them open like a clothes-dryer-vent, and then they fall shut when the blower stops.
http://www.dickblick.com/products/blick-plaster-cloth/?clickTracking=true&wmcp=pla&wmcid=items&wmckw=34134-1800&gclid=CjwKEAjwtLO7BRDax4-I4_6G71USJAA6FjN1yc1CwOSXLcaodljPEdJYKPQFqEvG1JjUioH--vsEzBoClerw_wcB

hydra-glide I dunno that I would worry about the math on the tape just buy some I keep lots of stuff like this on hand. I think you are talking about hand crafting a 6 inch duct and now it has light leaks. Gorilla Duct Tape is light proof but although Gorilla tape is fairly water proof it isn't really all weather. For all weather you would be better getting some rubberized or flex paint they use for roofing. If I didn't understand the question I'm sorry I tried very hard.

"hand crafting a 6 inch duct and now it has light leaks."
Hand-crafting a spiral of 4" plaster-tape around a new 25 ft. section of flex-pipe after it's in place with all of the (3) attached, metal vent-90's. Actually, two 10' lengths, one at each opposite gable, bent to what ever configuration necessary, and then frozen in mummy-wrapped cement.
The moist and muddy tape is wound around the pipe, or 12" length of plaster tape is section-wound around the flex-tube in a spiral 1" overlap, that will completely cover the flex-duct, and eventually (1 hr.) harden to plaster-of-Paris rigidity.
No, there are no known pinhole leaks in the flex-vent at this time. If they appear, I'll probably have some extra plaster tape to cover the leak (thnx for the suggestion). I'm doing this because the foil tube is going to take some hits, and suffer a hard life.
Next year, they'll be a special breed of 6", flex-vent made for this purpose in 10' lengths, as there should be. My cursed life. Pioneering stuff.

So it sound as if you're going to recirculate you're air? If so are you incorporating CO2? What about cooling?

Not re-circulating air. Forcing it out side with this squirrel-cage blower. If this won't cool the GH down to 80-82-degrees, then I'll add another blower to the opposite gable end.

You shouldn't have problems with light leaks from you're blower. If you are than 2 90 degrees elbows are enough to control it. No need for 14' of duct.

Have to have duct work, to go under the light dep. tarp and exit to atmosphere front of bldg. for intake, back of bldg. for discharge.