Factory Sea Cock?

[rnummi]

Thanks guys... I'll make sure they're all Marelon. Can someone walk me through the pull/rebed/replace routine? I was thinking of zapping through the interior skin and pouring epoxy all around hole. Would I still need a backing plate?

[Northern Spy]

To clarify, my understanding is that the through hull is the part that goes "through hull" and the seacock is the part with the valve. The black ones on your vessel look lie Marelon seacocks from Forespar. The through hull fittings look like factory. Google search for through hull dezincification and you will probably come to the same conclusion I have. I'm going back with all new marelon bedded in 4200.

[rnummi]

Yep, my marine speak has been unused for 20 years... It's coming back. All: is there any particular reason to keep the "type" of through hull the same? i.e. Spaghetti strainer vs. "scoop" vs. wide open.... As I replace, should I go for similarity or uniformity. To wit: the scoops are there to provide "ram water pressure" the spaghetti bowl is there to assure no over pressure, but no gunk gets in, the other ports are open to not snag macerated head discharge as it exits...... Etc. Etc.

I'm inclined based upon my previous observations to think it was whatever they had within arms reach at Cos Cob that day.

[Beta Don]

The sloped bronze piece is separate from the thru hull - It's screwed on the bottom of the hull separate from the thru hull to keep the engine raw water from getting plugged up should it try to suck up a plastic bag or other debris. The slope helps wash the obstruction away when the boat it moving forward. I guess you're calling the round one the spaghetti strainer. It is similar to the other one in that it's a separate cover screwed over the head of the thru hull and it's also to try to keep debris from plugging up the thru hull. Clean those up and you'll see the little screws which mount them. Remove the screws and the bronze pieces will come off and you'll see the thru hull underneath

You are correct - Thru hulls which exit fluids have no cover . . . . ones for water inlet usually do

Conventional wisdom in mounting thru hulls is to drill the hole, remove the core from around the hole back 1/4 inch or more, fill the void with thickened epoxy (this prevents water from getting into the core) and when that's dry, clean up the hole and mount the seacock using a backing plate. Teak would make the ideal backing plate, but I have made many using plywood and then soaking the ply in a couple of coats of epoxy all around. 4200 or 5200 on the outside under the head of the thru hull, more of it between the backing plate and the inside of the hull and then tighten everything 'firmly' but not overly tight - You don't want to squeeze out all of the 5200. Wait 48 hours and then tighten another 1/4 turn or so

If your early boat is like mine, there's already a built-in backing plate on the inside of the hull - Mine's about 12 by 12 inches and is glued to the hull. The purpose is to keep you from squeezing the hull so tightly that you crush the coring material

Don

[tego]

What Don Said! Ben

[rnummi]

Muchas Gracias... After perusing the board, I'm in Sprig's camp: replace everything, then you will know for sure. I've got the boat up, might as well sleep soundly. Any idea what the size/spec might be (for the through hulls). (Or alternatively, are they the right size for the job? For that matter, is there any trick to taking them out? I'm also going to replace the non-Marelon cock's w Marelon.

[Beta Don]

If they were properly installed, they will be *very* difficult to remove. If you can break them loose by turning with a pipe wrench, you can maybe drive them out using a block of wood and a two pound hammer - Good luck!

Yes, they should be sized for their particular application. I think you can assume the one for the engine is the correct size. You'll have to size the others based on what you'll be using them for

Don

[rnummi]

Yeah I see your point. I was on the albineers British Columbia website in the projects section where he took a look at his throughulls. If history is any indication..... Mine/ours are probably in same situation.

[rnummi]

Www.albinbc.com.

Disregard my last.. They were illustrating the seacocks not the through hulls I believe. It's in the member projects section under "sea cocks".... I'm having another senior moment.

[Sprig1]

I took mine out with a wood chisel.

[rnummi]

Chris: do you remember their condition? Solid core or balsa?

[Sprig1]

It cored that's why I was saying dig out the coring and put thickened epoxy around edges to seal it up. I even replaced all mine above the water line there is no coring there. You will be ahead of me soon I haven't worked on my boat in a few months. But I think about it a lot. Keep up the good work

[rnummi]

Thanks, I just discovered another hitch. My boat has no holding tank.... Aaargh! I'll start a new topic for it.

[rnummi]

Better angle on the odd seacock.

[Beta Don]

I agree you should probably change all the hoses - You do have one piece of ShieldFlex there, but it looks old and cracked - Probably 30+ years old and original to the boat, so it's wise to replace even that hose. That's the type of hose you want on all your seacocks. All of the other hoses are of lesser quality, so it would be wise to replace those regardless of their age. I don't see a water strainer there anywhere which is a bit odd. Usually the seacock leads straight to a bronze water strainer - Even a tiny bit of trash can do in a water pump impeller

The yellow handled ball valve definitely needs to be replaced by a real seacock - It would flunk any survey and make it impossible to get hull insurance

All below the waterline thru hulls, fittings, seacocks, hoses and clamps should be double checked and anything even slightly questionable should be replaced - You'll sleep much better if you do

Don