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View Full Version : Why So many Thru Hulls?



Larry Exum
03-20-2002, 02:30 PM
Why did Chris Craft ( and other boat builders) put in so many water intake thru hulls. My thinking would be that each additional one is a flood waiting to happen. My boat has one for each engine(2), one for each head (2), One for the Generator, one for the Air conditioning system water pump, and probably others that I have not found yet.

In every case, all of them have corroded to the point that the valve would not close. Indeed, prior owners never did any maintenance, but why use materials which corrode so easily in a boat meant for salt water?

Also, many of the thru hulls are located in places that are inaccessable after the boat is complete. I found one for the master head by following the hose from the toilet under the shower, under a cabinet, and then had to remove the drawers, drawer slides, and then a section of floor had to be CUT out since the screws that held the floor down were under the shower stall. NUTS !

Why not have only two, one for each engine, and then have branches off to the other items which would only need water occasionally. It seems the much safer plan. Am I wrong?

Scott Rosen
03-20-2002, 02:49 PM
Hi Larry,

I just replied to your other post on through-hulls.

The short answer is this: Chris-Crafts are not particularaly well-made boats. Yours was not well maintained. That's a bad combination.

The other answer is that with multiple through-hulls you get the ever important redundancy. If one of the head intakes gets clogged or broken, you still have another. Same with the engine. It just takes a little more dilligence to maintain four intakes instead of one or two. Plus if you lead the head intake off the engine intake, you might have trouble getting a good flush when the engine was running. And you'd need some kind of check valve to protect the delicate pumpworks in the toilet.

Sounds like you need to replace all of your through-hull fittings and maybe do some plank repair too. Did you get a survey before you bought the boat?

Larry Exum
03-20-2002, 02:56 PM
Yes, survey was done. A lot of comments about the maintenance, and questions of my committment to the project, but a finishing result of a very solid boat with much needed to be done. The surveyor suggested that an inland lake would be the best retirement home for her, and to NOT CONSIDER ocean use. I'll heed his advice, and keep her in Lake Lanier, Georgia.

Ian McColgin
03-20-2002, 03:01 PM
Scott's right about the need to look closely.

There have been boats made with water lockers (as opposed to water closets) but even they have a seacock for every pipe on the manifold.

Generally it's not a bad idea to have differently sized thruhulls for each major thing - like a rawwater intake thruhull with strainer for each engine allowing shut down of one, etc etc. Many discharge thruhulls could with profit be placed above the waterline. I personally think this is a good place for pump discharges, cockpit drains, etc. You still want sea cocks on each.

The epoxy blob is a very bad thing as it will hide trouble till you have catastrophing failure.

Check them all, service or replace as needed, and secure the wood. Beats sinking.

G'luck

Scott Rosen
03-20-2002, 03:30 PM
I'm not picking on you, or anything like that. I just have a question.

That's a big boat with a lot of power. What kind of inland lake would you keep her on? Any lake big enough for your boat would produce waves as big as any you'd encounter in coastal saltwater cruising.

If I were paddling my canoe on a nice quiet inland lake and saw a 45 foot Chris with twin something or anothers bearing down on me, I'd probably have a heart attack.

brad9798
03-20-2002, 03:56 PM
I doubt there is an inherent problem with keeping her on the ocean as a coastal cruiser.

If she's not safe in the ocean ... she's not safe on a lake. Sounds like a biased surveyor.

I have a 1964 Chris ... fresh water her whole life ... and yes, 38 years later, it makes a big difference on the overall condition vs. hours of maintenance needed. My through hulls are original, and fine ... all four of them.

Good luck.

Brad

Wayne Jeffers
03-20-2002, 04:05 PM
Originally posted by Scott Rosen:
. . . Any lake big enough for your boat would produce waves as big as any you'd encounter in coastal saltwater cruising.

If I were paddling my canoe on a nice quiet inland lake and saw a 45 foot Chris with twin something or anothers bearing down on me, I'd probably have a heart attack.I looked it up. Lake Lanier . . . 38,000 acres, 540 miles of shoreline . . . nice lake.

There are bunches of boats in the 35 foot range on Summersville Lake, high in the mountains of West Virginia, and it's less than one-tenth that size, and mostly real skinny to boot. Goodness only knows why. Party barges? I guess people have the money and they gotta spend it on something. We checked out Summersville Lake last year as a potential place for sailing and concluded that 1) there wasn't enough room for good sailing and 2) it was much too crowded with boats that belonged in the ocean, not on a mountain lake. :eek:

Wayne

TomRobb
03-21-2002, 10:54 AM
There's a system of natural and impound lakes near here that used to feed water to the Ohio and Erie Canal. On one of them, about 500 acres, I saw a guy roaring about in a Cigarette race boat. :rolleyes: He hardly got going before he had to turn to miss the far shore.
The world is full of idiots.

[ 03-21-2002, 10:55 AM: Message edited by: TomRobb ]

Wayne Jeffers
03-21-2002, 12:49 PM
I learned only recently that Buckeye Lake (3400 acres) was built in the 1820's as a feeder for the canals. Impressive.

http://www.dnr.state.oh.us/parks/parks/buckeye.htm

Wayne

TomRobb
03-21-2002, 02:26 PM
Don, it was on Turkey Foot lake, one of the Portage Lakes.
And for the rest of you, yes it's a wierd name but that's what a map of the lake looks like - a turkey's footprint. Aptly named given the sort of shenannagans going on out there in the summer.

SailBoatDude
03-21-2002, 08:08 PM
Redundancy is survival. Replacing thru hulls is a pain sometimes, but indeed the life of a boat owner. Reasonable care can really increase their useful life.

I don't use water cooled anything, self contained or raw. Just another system to tend and maybe breakdown. Air cooled engines never really caught on in the states, though you see a lot more of them overseas. Air cooled requires intakes and exhausts, but not at the potential of flooding the boat. The heat can be used for a number of things like hot water and warming your feet at the steering station on cold runs. They also require no moving parts to get the air in and out (like water pumps, sea cocks, etc.) Air cooled systems are lighter, though noisier, but the extra insulation needed weighs much less then the water jackets on a liquid cooled rig. There cheaper also.

It does sound as though the surveyor found what he was paid to find. Talk to a shipwright . . .

SailBoatDude
03-22-2002, 12:00 AM
You usually get what you pay for. You want a positive survey for a sale, you'll get one most of the time. You want an assessment of a boat for repair within your budget, you'll probably get one around your budget. Just like car mechanics, you have to find one that you've developed a trust with over time. Not to say all surveyors are butt kissers, they aren't, but what's up with the keep it in the lake crap? Boats sink in lakes too . . .

Air cooled equipment doesn't have underwater thru hull issues . . . Donnwest, (no it doesn't mean repower with a VW engine to solve thru hull replacements)

Dave Hadfield
03-22-2002, 02:11 AM
Drake has had three engines and at least three different heads and has far far too many thru-hulls. They make me nervous too. You need to check/replace every single one.

The need for this was brought home to me last fall when I was winterproofing the head and turned off the valve (seacock) for the water intake. The lever didn't move. I bore down on it. It still didn't move. I squirted WD40 all over it and torqued it hard and the complete thru hull broke off in my hand. The thing was corroded away to nothing.

From the outside it had looked fine. Big bronze fitting. The surveyor never said anything about and I don't blame him. But next month I'm going over every old hole in the boat with a suspicious mind.

wolfietuk
03-22-2002, 05:57 AM
If I was told a boat was not fit for the sea there is no way I would use it on a lake. We lose more boats around here on lake murry and lake marion than on the sea. No you will not have 75' waves on the lake, but you can have 6 to 10' with 3 to 5 second frequency. and these can build up in seconds with afternoon thunderstorms. People do not take it seriously because it is "small water". That type of wave action can literaly break a boat in two. And dont even think of swimming to shore. Mind if i take out an insurance policy on you?

Rick