I don't own a boat. I'm too old to start building a boat. I can't afford to buy a boat. But I look forward to every one of your videos. You hold and share a wealth of knowledge. Exactly what YouTube should be. Thanks!

I am a boatbuilder myself, unfortunately never got arround to wooden boatbuilding much, there I enjoy your series a lot

Excellent!

I always put an 90° elbow OUTBOARD of the ball valve to make it sit horizontal, less vulnerable, and pipes lay flat along the hull. I also put a large SS flat washer between block and flange nut to assist tightening.

Hey! Just this morning I was thinking where did Smithy go? And there you were as soon as opened up. So looks like I've got some catching up to do. Interesting video.

very cool

I often wondered why boats have a seacock? I didn’t think it was just to provide sea water to cool engines. Does a sailing ship have seacocks?
Authors of action books such as Alistair Maclean mentioned opening seacocks to scuttle ships.

At 1:00 the video shows a through-hull fitting being connected directly to a ball valve. This is common practice, but incorrect. The through-hull uses a straight thread by necessity, since it must typically be cut to length when being installed. The valve, on the other hand, uses a tapered thread. While the diameter and pitch of the two are compatible, the combination of straight and taper means that there is only a narrow region, perhaps one or two turns of thread, which are in close contact. This results in a poor seal and low mechanical strength.

Groco is one manufacturer which makes an adapter specifically for through-hull fittings. It takes up more room than connecting the two parts together directly, so in a tight bilge space it may not be suitable, but it is a very secure solution wherever it can be used. The adapter has a flanged base to distribute load against the hull, but you should still use a wooden backing plate against a wood hull.

An alternative to the adapter is to have a taper cut in your through-hull threads after you've cut the fitting to length. Remember to allow sufficient length to take up the taper-to-taper mating of the threads. This will require several turns more than would be the case for an abrupt taper-to-straight fit. Unfortunately, it can be difficult to find any shop equipped to do this cut. Plumbing shops have the correct tapered dies, but they're generally set up for clamping long pipes, and won't work with through-hulls that have almost no shoulder next to a wide outer flange. Any good machinist can turn a tapered thread (and who doesn't enjoy cutting bronze?) but the setup time can make this work prohibitively expensive.

If you absolutely must fit a straight thread to a taper, plan to use ample threading compound, and find a way to mechanically support the assembly once it's been fitted. Also make sure that you're supplied with tapered plugs that will fit the bore of the through-hull if it should fail at the weak spot.

What kind of sealant do you recommend?

The proper name for an Crescent wrench/adjustable spanner is  "mexican socket set"......if you're living in California.