Vinyl signs out in the wind ? how do you cut air flaps ?

[trackvw]

Hi

we sell a lot of signs for swap meets and car shows ,
most are hung on EZ-Ups or other canopies ,

the problem is in the afternoon the wind picks up and the signs add to the "lift" to make the EZ-Ups want to fly away,
We have cut "air flaps" , a U shaped cut to let the air pressure out , but is there a better way ? Or any studies on where is the best place to put the flaps ?

Thanks for your ideas VW

 

[J Hill Designs]

Here is how not to do em

 

[Pat Whatley]

Here we go again.

Wind slits do virtually NOTHING to reduce the wind load on a banner. If it's that big and issue print mesh banner.

 

[Pixels Are Bad Mmmkay?]

What I don't get is that people will pay well over a couple hundred dollars for a nice banner to put outside and then they go and string it from two posts and let the wind beat it to shreds. I would never suggest wind slits in high wind areas. Rather, I suggest the customer buy some 1/2" plywood and mount it to that. A $25 piece of plywood mounted between posts will allow a banner to last indefinitely as opposed to a few months. It also just looks more professional as it stands flat and won't sag.

 

[trackvw]

Most EZ-Ups will not support a 4x8 piece of plywood , and how do you get it to a show ?

My best EZ-Up has a wind flap in the top , it lets the trapped air out so it does not become a kite , and yes I have had one with wind flap and one without next to each other at a show and it does work...
when it gets real windy I undo the back corner of the EZ-UP and let it flap in the wind to let the pressure out,

I am talking 10 mph winds , not 30mph which we would just take them down....

I read the other thread and it was all over the map on if they worked or not ,
I know they will not work 100 % , you will still have a lot of square feet catching the wind , hey even the poles catch the wind !

These are going to be up maybe 24 hours at a time , but probably less than 10 hours , one or twice a month.....

VW

 

[Pixels Are Bad Mmmkay?]

Most EZ-Ups will not support a 4x8 piece of plywood , and how do you get it to a show ?

My best EZ-Up has a wind flap in the top , it lets the trapped air out so it does not become a kite , and yes I have had one with wind flap and one without next to each other at a show and it does work...
when it gets real windy I undo the back corner of the EZ-UP and let it flap in the wind to let the pressure out,

I am talking 10 mph winds , not 30mph which we would just take them down....

I read the other thread and it was all over the map on if they worked or not ,
I know they will not work 100 % , you will still have a lot of square feet catching the wind , hey even the poles catch the wind !

These are going to be up maybe 24 hours at a time , but probably less than 10 hours , one or twice a month.....

VW

Oops! I don't know how, but I missed that part about EZ-Ups. Sorry for the unnecessary rant.

 

[trackvw]

Oops! I don't know how, but I missed that part about EZ-Ups. Sorry for the unnecessary rant.

As Chick Hearn , Lakers announcer would say

"no harm, no foul "

also between 2 poles may be the only place they can put up the sign , you work with what you have

VW

 

[ChicagoGraphics]

print MESH!!

 

[Locals Find!]

Your problem is not the banner. Your problem is your improperly secured ez-ups. Winds slits or not your ez-ups aren't weighted down properly. My suggestion would be to invest in a couple of 1 gallon buckets of concrete and secure them to the 4 legs of your ez-up.

I have been using these ez-up style tents for many years longer than I been in the sign game. I have never seen one get blown away or even lift up when properly secured with or without a banner. Hell, I have seen em with 3 walls in 35 mph winds not even think about tipping when secured properly.

So, stop trying to screw up your nice banners with some stupid holes when the correct solution has been staring you in the face the whole time.

 

[Craig Sjoquist]

Take 2 long PVC pipes about 2" ,, cross between both sides making a + ..secure with ball bungees ,,,done

Your tent will hold up to more wind & support banners better

 

[Gino]

To answer the OP's original question............

Take a large coffee can and using an xacto knife, trace around about 2/3's of the can leaving the floppy connected part at the top. Try to avoid letters if you can.

Any banner gonna be in high winds, should be taken down before the winds start up. If not, you'll be sorry when you find out what damage a small sail can create when Mother Nature takes hold of it.

 

[Pat Whatley]

Here's the graphic I made several years ago that I send to customers explaining why I refuse to cut wind slits in a banner. On a 3' x 10' banner the reduction with wind slits is only 4% with 50 wind slits. Just not worth the minimal savings in my opinion.


And because I'm bored...and curious....

If Force can be figured as Force = Area x Wind Pressure x Drag then a 10 mph wind hitting a 3' x 10' banner at a perfect 90 degree angle would provide a maximum of 66.2176 pounds of lifting force. The same banner with wind slits provides 63.802 pounds of force.

 

[trackvw]

OK....I looked at your attachment and agree with you calculations......

but I am not sure if that is the question , that the total square feet is the only thing ,
I am not an engineer , I wish I knew one to give me the "engineer" answer ,

But I would think lowering the pressure by letting the air thru has got to be good for something !

Any engineers out there ?

 

[Pat Whatley]

Lowering the pressure is good, the problem is that wind slits are a very ineffective method of doing it.

 

[John Butto]

If you put holes in the sails of your sailboat you will slow down for sure. So take a coffee can and a utility knife and cut half circles in the banner and report back with your findings.

 

[xxtoni]

Those things are hideous.

If the banner is really big they won't help either. If it's a really big thing print it on mesh. It won't have the same color intensity but it's pretty much the only way to do other than securing banner to a wall with profiles or the like.

We print decently sized banners that hang over narrow streets from time to time and it's never really been an issue as far as wind is concerned but if you're really in a fast wind location I think that mesh would be the only good looking solution.

Holes in the banner just look unprofessional and i'm not convinced of their effectiveness.

EDIT:

When you think about it...wind isn't a liquid. It's a matter of area and those few holes won't reduce the area of the banner a whole lot so it won't improve the wind flow a lot so basically you're just ruining a nice banner and it won't help a lot.