Is there a formula or recommendation for size and placement of wind vents in a banner. I'm working with 2 sizes - 60" x 30" & 160" x 36" - both 14oz.
Thanks.
Posted by Santo (Member # 411) on :
I don't know about the cuts. So I can't help with them. Seems to me it would be smarter to string it tighter than the elastic on Aunt Elsie's drawers on the top and use bungees on the bottom.
Posted by VICTORGEORGIOU (Member # 474) on :
Hello Robert
There are two schools of thought on wind vents.
One theory is that wind vents weaken the banner material and result in premature banner failure. Wind vent blowouts are just that - no more banner. Without vents, the banner tears at a seam which is usually repairable (but not always)
The folks on the other side of the argument say that the weak point of a wind vent is the spot where the cut ends, and you just strengthen that point by rounding the edge with a hole punch, or by putting a spot of adhesive there to prevent a run.
If your client insists on wind vents, I would suggest 18" to 24" intervals, 6" semicircles, flap down so that gravity keeps it closed.
Position them visually to minimize the impact on the banner's message.
Posted by Si Allen (Member # 420) on :
Forget the wind vents! They really don't do much, EXCEPT become a source of tears!
For example: If you cut a 12" half moon every other foot, above and below the line of copy...on the 160" banner you will wind up with 12 cuts. That is only 14% of the surface area! Not only will it look ugly, each and every one of those cuts is a source for the material to tear!
Just my humble opinion!
Posted by Jeffrey Vrstal (Member # 2271) on :
I used to cut them in all of the time... really hated that part after doing all of that work. I read an article or maybe words from a manufacturer saying not to cut wind holes. OK, so I tried it. I haven't cut one in 6 or 7 years now and all have held up well. Bungee-ing 4 corners seems to be the way to go for me. Once in a while you might have to tighten up the cord if it stretches out... or tell your client to do that.
Posted by Gavin Chachere (Member # 1443) on :
Robert...follow Jeffery's advice and secure them from the corners tightly so the entire banner surface can take the wind pressure uniformly like the sail on a sailboat.....if you make cuts in it,you have the same principle as an airplane wing...air going thru the cut creates "lift" at those points and is gonna cause the banner to bow backwards toward that lift,thats why you so often see windcut banners you can hardly read because they're bent in half,not to mention yes it looks ugly and yes no matter what you do it seems to tear at the cut points. Just my .02
Posted by TransLab (Member # 470) on :
With 14oz vinyl I wouldn't worry about wind vents in anything less than 3' x 16'. on a 20' x 3' banner I would cut 4 or so.
Posted by Stephen Deveau (Member # 1305) on :
Mike
Living in "Labrador City" You don't see much Wind! EH!
Not that the "Roads" to your far grounds are the best of the (Canadian Trans Canada Highway)
Sorry Guy....
But a Wind Sail across the street will need venting. Unless you plan to watch it drag poles and all down the Main Street.
Been there (Labrador City) Posted by Robert Graham (Member # 1167) on :
Thank you for your replies and help. They have been very helpful. I don't think the vents will be necessary the way these banners will be used and mounted. Thanks again.
Posted by Randy Campbell (Member # 2675) on :
Robert; Jeff Does what I do ,Put bungies on eash corner.Never had one rip yet.
Posted by Ernie&DianeBalch (Member # 1301) on :
We have some towns around here that sign ordinace Requires Over the road banners to have wind slits. You just can't convince to bungee the 4 corners. Its fun changing the temporary lettering portions on those banners!
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