These Yumore L-brackets are indeed sturdy. However, the stainless steel is of low grade, and definitely not for underwater applications. I used them to reinforce a pool rail with stainless steel fasteners. Shortly after these brackets were submerged in the swimming pool, rust began to form particularly at the holes for the fasteners. After one summer, you can see the rust stains left from those "stainless steel" brackets. I just replaced the Yumore L-brackets with smaller (304 Stainless) brackets from a marine supply store. The smaller brackets are not as robust and I hope they fair much better this summer.
Collapsible Shelf Brackets - Heavy Duty Metal Folding Bracket For Wall Mounted Bench, Table, Or Shelf, Space Saving Hinge Design, 2 Pack, Maximum Load Capacity Of 150 Pounds (14 Inch, Black)
27 Review
ETECHMART 5 Inch Wall Mounted Floating Shelf Bracket, Pack Of 4 L Shape Heavy Duty Rustic Iron Metal Corner Brace Shelf Supporter For DIY Open Shelving Decoration - Black
20 Review
Pack Of 6 ETECHMART Rustic Iron Metal L-Shaped Shelf Brackets, 5 Inch Wall-Mounted Support For DIY Open Shelving, Heavy-Duty Corner Brace Shelf Supporter In Black
29 Review
Pynsseu 24-Inch Heavy Duty Folding Shelf Brackets For Space-Saving Storage – 2 Pack
21 Review
Eco-Friendly Solarez UV Cure Grain Filler & Sealer - Perfect For Fine Furniture, Guitars, Pool Cues And DIY Woodworking!
10 Review
32Oz Gorilla White Waterproof Patch & Seal Liquid For Effective Sealing (Single Pack)
30 Review
Gorilla Waterproof Patch & Seal Liquid - Black 16Oz - Ultimate Solution For Quick Fixes (Pack Of 1)
39 Review
Pack Of 1 Natural Wood Color 8 Ounce Bottle Gorilla Wood Glue
42 Review