When we took solar cover off pool to close for the year, we found a tear in the winter cover and I decided to repair it rather than spending $300 and waiting a week for shipment. We set up the sewing machine in the drive.
Torn pool cover.
Cutting a piece of tarp to use as patch.
Laying out the cover and a patch on the top and on the underside.
Cover on pool. Not very pretty but will do the job til next year.