Sample preparation task 4, by E. Sichel on Feb. 19, 2002

Shown are 3M Co. Automix Fast Cure Epoxy Adhesive 051135-08107 in an applicator gun with a mixing nozzle to mix the two-part epoxy, Hardman wet surface patching epoxy #04003, and a bottle of experimental Ceramicrete (powder), developed by Dr. Arun Wagh of Argonne National Laboratory.

Shown are scallop shells with a piece of netting sandwiched between them with Hardman wet surface patching epoxy.

Shown are scallop shells and netting with 3M Co. FastCure Epoxy 051135-08107.

Samples were prepared in a similar way to the procedure described in the Martha's Vineyard Shellfish Project report. The pieces of netting and the scallop shells were soaked in seawater and then blotted dry with a paper towel. The adhesive was applied to the shells and the netting was sandwiched between the shells. The sandwich was left on the bench top for about 15 minutes in air. The sandwich was then immersed in a tray of seawater, and the covered tray was stored in a refrigerator at 34 degrees F.

The Ceramicrete, which contains fly ash, was prepared by adding 100 g of the Ceramicrete powder to 50 g of distilled water. The mixture was stirred with a flat wooden stick for 30 minutes, intermittently. It was applied to the scallop shells and netting, and the shell/netting sandwiches were left to dry for 15 minutes in air on the bench. When the Ceramicrete was applied, it had the consistency of ketchup. When the shells and netting were immersed in a tray of seawater, the top shell immediately came loose, and the Ceramicrete began to disperse into a solution with the seawater. I conclude that the Ceramicrete should be left to dry until it has a putty-like consistency before it is applied to the scallop shells. This will be tried in a future experiment.

A stainless steel fixture was prepared for strength testing with the Ceramicrete bonding the two pieces of steel shim stock together for a tension test. The fixture was left to cure in air. It will not be immersed in water.

The adhesive bonds will be inspected in about two weeks.

Inspection Report

The samples were inspected on March 4, 2002 after 13 days in seawater in the refrigerator. The refrigerator temperature dropped to 25 degrees F, so the average temp. of storage is between 34 and 25 degrees F.

• 3M Co. Fast Cure Epoxy Adhesive 051135-08107 formed an excellent hard bond to the shells and the netting.
• Hardman wet surface patching epoxy #04003 formed an excellent hard bond to the shells and the netting.
• Ceramicrete bonds came apart. A pool of Ceramicrete with embedded shells did harden, but it is not strong enough to hold a shell to scaffolding. Shells that had been pressed into the Ceramicrete could be easily pried out of their position and the bed of Ceramicrete was easy to break. It was slightly crumbly under prodding.