garden. What to use as a aluminum sheet product to sink along the edge of my garden to help combat this grass weed?
I would opt for galvanized steel! This is the most common garden edging. You can check places like Ebay, Etsy, or Amazon.
Some tell you to dig a trench first, and others will have where you can hammer them in, and be done.
Any idea what this grass is? It's invading an area of sand that I would like to keep sand!
My best guess would be Kikuyu Grass (Cenchrus/Pennisetum clandestinus). It is not native to your area, but was introduced from east Africa to here, where it is considered invasive.
Unfortunately, the only way to get rid of this aggressive pest is through chemical control. They spread by runner, seed, and any stolon that breaks off of the plants, making it incredibly difficult to kill. General herbicides will be the answer.
This article will offer more information:
https://www.gardeningknowhow.com/plant-problems/weeds/control-of-kikuyugrass.htm