I wanted to find a glue that was simple to use, not too expensive, was very strong, and would maintain its strength in wet conditions. There are many glue options to choose from. I ended up choosing two popular brands: Liquid Nails and Loctite. For each brand, I chose either the strongest option or the option that was designed for wet environments. I didn’t include epoxy in my test because I didn’t want to mix two parts together and apply the mixture using a stick. Below are the two options I chose.
- Loctite PL Marine 10 fl. oz. Fast Cure Adhesive Sealant
- Liquid NailsFuze It Max 9 oz. Interior/Exterior All Surface Construction Adhesive
I first glued a piece of 2×4 to a concrete landscape block.
After waiting 1.5 to 2 days to fully cure, I attached each piece of wood to a chain to suspend the wood / concrete block combo in the air.
After 2 days, both adhesives kept the wood attached to the concrete block. I then wanted to see if water would affect the bond. I submerged each test in water without having it touch the bottom of the bucket of water.
After 12 hours, the wood pieces were still connected to the concrete blocks. But, after 23 hours, the Liquid Nails Fuze-It MAX lost its strength and the wood piece became disconnected from the concrete block.
So, the winner is Loctite PL Marine, although if you are gluing something in a dry environment, Liquid Nails Fuze-It MAX is probably sufficient. Unsurprisingly, the Marine adhesive is stronger both in dry and wet environments, including while being completely submerged in water.