Cutting holes for large grommets
Grommet kits include an assortment of grommets in several sizes and all the installation tools required. Kits are available at hardware stores and home centers. (We used 1/2-in. grommets for this repair.)
Determine exactly where you want the grommet and mark the location. The hole cutter in the kit has a beveled edge that cleanly cuts a grommet hole in the tarp (Photo 1).
Then sandwich the grommet and washer around the tarp and pound them together to complete the grommet (Photos 2 and 3). Make sure the punch is completely inserted through the grommet post and into the center of the anvil. Otherwise, the grommet and washer won't seat together fully and the anvil may be damaged.