Marine Adhesives

report prepared by MMA engineers: 1/C Foley 3/C Sunde ________________________________________________________________ PSI-326 can be mixed (resin and hardener) underwater, as well as applied underwater. Reports follow. ________________________________________________________________ This past Tuesday, my technician and I tried to test (whether) the adhesive (PSI-326) would mix under water. Using a sponge (paint) brush with the sponge ripped off, we were able to successfully mix and apply the adhesive on a submerged rock. (Editor's note: there is a plastic spatula under the sponge brush.) We did three tests-- successfully adhering a nail to three differant rocks. Once this was accomplished, we then tried adhering the spatula itself to the rock. It would adhere, but because the handle was made of wood, it would lift right off. We then fashioned some aluminum spatulas, but due to human error, I believe, these would not stick. On 10/16 we experimented with building an adhesive/marker applicator for Alvin underwater (use). In the previous labs we determined that "Smart Glue" was the best choice for underwater use in this lab. We met today's goals by finding out if the epoxy will mix underwater. We put a half teasspoon of resin on a rock and added a half teaspoon of hardener and then stirred them. We (embedded) a plastic tab, a piece of glass and a nail in the epoxy. They all hardened (set up), but the nail worked the best. I worked with the sponge applicators and found that the foam type paintbrush worked very well when applying such items as the nail and plastic tabs to (our) Buzzards Bay rock collection. What also worked extremely well for me and my technicians was the brillo type scrub pad, using two separate cut out pieces of the pad. We added hardener to one piece and resin to the the other piece and then applied it simultaneously to a rock underwater from Buzzards Bay. We found (we) must soak the pads well for the best results. What (produced) the worst results, but wasn't a complete failure, was the mesh sponge. It was too porous and the size was too large. In the next lab I plan to experiment and cut up mesh sponges into smaller sizes because as they are now they require more "SMART GLUE" than we have available. Maybe (I will) use elastic (bands) or some other type of fastener to keep a tight hold on the sponge so it will stay together better during the compression of the sponge to the rock and (during) the twisting motions. The ambient seawater temperature for this lab was fourteen degrees Celsius.