Re: [PSUBS-MAILIST] concrete encasement for thruster

["james kocourek" <kocpnt@lakefield.net>]

Hi Brian,

 

Interesting Idea. One problem that will need to be addressed is the fact that concrete shrinks as it cures. Not a great deal, but it does shrink non the less.This would make it difficult to maintain a tight bond at the seal mating surface.

 

Best Regards,

 

Jim Kocourek

----- Original Message -----

From: Brian Cox

To: Personal_Submersibles@psubs.org

Sent: Tuesday, June 19, 2007 11:15 PM

Subject: [PSUBS-MAILIST] concrete encasement for thruster

         Has anybody considered encasing a thruster motor in re-enforced concrete as a way of isolating the motor from the seawater and pressure?  If you could first seal all of the openings where you don't want cement with silicone or equivalent and then route your electrical wires thru an epoxy potted section I think it could work.  The motor shaft would have to be a good ceramic seal.

        Since the cement would be in contact with the motor housing you would probably get good heat transfer to the cold seawater also.    After the cement has cured coat it with an epoxy.

      If you had a malfunction, like a leak, or some other problem you could cut open the cement with a carbide blade, take the motor out, and then just pour a new concrete encasement  very cheaply. 

 

Brian Cox