Thank you for your help and suggestions. We are going to use upholstery thread hoping it will be the best way to go. I found sun resistent thread, but it was $139. for a large spool (too much money). The cover will be hung inside using grommets which we will reinforce. So I'm off to Joann's tomorrow so I can use my coupon.
I can't wait till the end of July when our local Joann's will open. Now I have to drive 45 min and end up spending more money than intended cause I'm right in the middle of some nice shopping. Bad for the budget!
Thanks again!