A vinyl tarp is a handy item to keep around. It can provide instant cover and protection for items exposed to the elements, yet be folded and stored when it is not needed. Vinyl tarps are typically sold in standard sizes, with hemmed edges and grommets evenly spaced around the hem. To function correctly, the vinyl tarp should be just large enough to cover but still have additional area to be held in place with the grommets. Your vinyl tarp may need to be resized to properly cover or protect an item or area.
Position the vinyl tarp over the area to be covered or simply spread it out on the ground.
Mark a line where you want a new edge for the tarp. Remove the vinyl tarp from the area to be covered and lay it flat.
Lay a yard stick along the marks you made and re-draw them so that they are straight. Draw another line alongside your existing line, 2 inches away, to allow for a hem.
Cut off the excess tarp material along the outside line.
Clean along the cut edges of the vinyl tarp using a washrag dampened with a solution of ¼-cup dish washing detergent to 1 gallon of water. Clean an area at least 4 inches wide along the cut edges and allow the area to dry completely.
Apply vinyl cement or glue along the outer 2 inches of the cut edges, following the vinyl cement package directions. Fold over 2 inches of the cut edge to create a hem, glue it down, and allow the cement or glue to dry completely.
Punch grommet holes in each new corner and along the sides. Position the holes in the middle of the 2-inch hem and space the holes no further than 2 feet apart.
Insert a flanged grommet into the hole and cover it with a flat grommet. Set the grommet using the grommet setting tool and a hammer. Repeat the grommet setting process for all of the punched holes.