How To Properly Install Seacocks For Marine Vessels

Seacocks are valves that are placed on the hull of a boat or ship which in order to allow water to flow in or out of the vessel. They can be used for varying applications, including the cooling of engines with sea water to the removal of water from a sink drain. While many individuals may want to use a through-hull fitting, such additions can be risky as they can sink ships if not formed correctly. While a tee connector on an existing inlet is most preferred, there are times in which a new through-hull fitting is either needed or more advantageous. In this blog, we will provide a brief overview of how seacocks are safely installed or replaced on marine vessels.

Before creating a new through-hole, the vessel should always be removed from the water to further safety. The first step of the process is to locate readily accessible seacocks before installing a new through-hull fitting. Prior to drilling the hole, one should always check to see if there is sufficient room on the outside and inside of the hull as well as ensure that the fitting will not result in increased turbulence. Once those steps have been carried out, a pilot hole can be produced so that the location can be reaffirmed one last time. As drilling begins, the correct sized hole saw should be chosen and one should always start from the outside before finishing up on the inside. After the hole has been produced, epoxy putty should be applied and allowed to harden so that the core material is protected from sea water.

If you are replacing a through-hull fitting, the first step is to unscrew the nuts and bolts that secure the seacock’s mounting flange. The seacock may also be removed with a pipe wrench if needed. If the fitting has polyurethane sealants, they may be removable with a threaded rod. Next, the washer components and fasteners are seated and secured, and any sealant residue is removed. To properly clean the inside and outside of the hull around the hole, acetone is recommended. Before finishing, check for any exposed core materials and treat them with epoxy putty as necessary.

Upon finalizing the hole, the final procedure of installation remains the same whether new seacocks are added or are simply replaced. Before implementing the seacock, a circle should be cut to a size that is slightly larger than the seacock flange. Then, the center can be bored to establish a ring and should be shaped with a rasp or sander in order to match the hull’s curvature. The ring is very important for installation as it both reinforces the hull as well as offers a surface for the seacock flange.

Next, the new through-hull fitting may be inserted and the seacock is then threaded. With the seacock secured, it can be positioned as needed before drilling mounting holes. For the mounting bolts, it is important to use the correct materials, as bronze seacocks require bronze mounting bolts and other materials may have their own needs. The seacock should then be seated and secured again and all mounting bolts should be coated with polyurethane sealants. Lastly, the bolts can then be reinserted alongside a washer and nut.

By following the correct procedures for establishing and replacing seacocks, one can ensure a proper assembly is made for the safety of the marine vessel. ASAP Purchasing is a premier online distributor offering customers competitive prices on marine components, aircraft parts, IT hardware, and much more. Across our various part and manufacturer catalogs, we offer customers access to over 2 billion new, used, and obsolete components sourced from leading manufacturers. If you find particular items that you wish to procure, we invite you to submit a Request for Quote form through our website and a dedicated account manager will reach out to you in 15 minute or less to continue the process. Get started today and see how we can fulfill all your operational needs with ease.



January 12, 2023
December 7, 2022

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