Building a '93 Caravelle 1750 Classic Bowrider

[skuhleman]

Also make sure to add some drain holes to the bottom back of the buckets, mine would hold water before I added drain holes.

 

[Baylinerchuck]

One of the things some of the guys from the forum told me when I was building my drainage system along the keel to the bilge was to install a valve at the aft end of the fuel coffin. They said that is was necessary to isolate the fuel cell from the rest of the bilge in the unlikely event the tank develops a leak underway.

In doing the demo of my boat, I failed to realize that the coffin the fuel cell sat in was completely sealed off from the drain water from the ski locker. The Poly fuel tank sat on a glassed in piece of plywood above the keel. This allowed water to drain under the tank coffin, not through it.

In my strife to improve drainage and ultimately air flow around the tank to eliminate condensation, I basically allowed a path where fuel could drain to the bilge. Obviously this creates a bomb. Luckily, I caught it early and modified my design to include a CPVC valve which isolates the tank from the bilge. I can open the valve to drain all points forward of the bilge when I want, and isolate the tank when required.

Just food for thought.

 

[Reserector_]

Also make sure to add some drain holes to the bottom back of the buckets, mine would hold water before I added drain holes.

Glad you mentioned that. I noticed that the factory drains were higher than the corners. I'll be sure to do that. Thanks!

How were the side panels (in the rear) attached to the cap?

 

[Reserector_]

One of the things some of the guys from the forum told me when I was building my drainage system along the keel to the bilge was to install a valve at the aft end of the fuel coffin. They said that is was necessary to isolate the fuel cell from the rest of the bilge in the unlikely event the tank develops a leak underway.

In doing the demo of my boat, I failed to realize that the coffin the fuel cell sat in was completely sealed off from the drain water from the ski locker. The Poly fuel tank sat on a glassed in piece of plywood above the keel. This allowed water to drain under the tank coffin, not through it.

In my strife to improve drainage and ultimately air flow around the tank to eliminate condensation, I basically allowed a path where fuel could drain to the bilge. Obviously this creates a bomb. Luckily, I caught it early and modified my design to include a CPVC valve which isolates the tank from the bilge. I can open the valve to drain all points forward of the bilge when I want, and isolate the tank when required.

Just food for thought.

I get what you're saying, but how is that any different than an above-deck tank (for example), or even a portable tank as used with outboard motors?
I read through the AYBC documents regarding permanent tank installations and don't recall anything about separating it from the bilge, but I will go back through it again. If I overlooked something, I need to find it now, not later.

 

[skuhleman]

Glad you mentioned that. I noticed that the factory drains were higher than the corners. I'll be sure to do that. Thanks!

How were the side panels (in the rear) attached to the cap?

If you look in my picture before interior, there are 1/2" holes along the top cap, the wood had phillips bolts through the wood, into T nuts on the back side of the wood. Then through the fiberglass then washers and nuts. So you could position the panel in place with the bolt through the hole and then put a washer and nut in and tighten down. I believe they were all 1/4-20 bolts so they had play in the fiberglass holes for accurate alignment.

 

[Reserector_]

If you look in my picture before interior, there are 1/2" holes along the top cap, the wood had phillips bolts through the wood, into T nuts on the back side of the wood. Then through the fiberglass then washers and nuts. So you could position the panel in place with the bolt through the hole and then put a washer and nut in and tighten down. I believe they were all 1/4-20 bolts so they had play in the fiberglass holes for accurate alignment.

No support below that, correct?

 

[skuhleman]

No support below that, correct?

Correct. The bolts kind of stagger on the top cap and that supports it from being too floppy. Also where the back seat meets it helps too

Actually I just remembered where it meets the back seat, there is 1 or 2 L brackets that attached the bottom of the side to the side square floatation boxes.

 

[Baylinerchuck]

I get what you're saying, but how is that any different than an above-deck tank (for example), or even a portable tank as used with outboard motors?
I read through the AYBC documents regarding permanent tank installations and don't recall anything about separating it from the bilge, but I will go back through it again. If I overlooked something, I need to find it now, not later.

yeah, I never really looked for it in the reference book. I more or less realized that I had unknowingly defeated what the original intent of the fuel coffin in my boat did. It was a sealed compartment. I added a drainage path with the good intention of mitigating condensation, hence making the fuel coffin unsealed. Adding the valve for the most part prevents fuel from getting to the bilge, but allows me to drain and dry the space when at home.

 

[kcassells]

Their is alot of debate/interpretation on this subject.
They have pics to demonstrate the descriptions. Easily available to find on google.

IT’S THE LAW - USCG: 183.550 Fuel tanks: Installation (a) Each fuel tank must not be integral with any boat structure or mounted on an engine Each fuel tank intended to be permanently installed, must be made as a separate component and then installed in the boat. Portions of a boat’s structure, i.e. hull surfaces, bulkheads, stringers, floors, decks, frames, etc., may not form part of a fuel tank. Fuel tanks glued, bonded or foamed-in-place are not considered integral and are therefore acceptable. However, that installation must comply with the applicable portions of this regulation. Fuel tanks may not be mounted on an engine, except if the engine is part of a portable piece of equipment that is not permanently installed in the boat. If a fuel tank is removed from an engine to be installed in the boat, the installation must comply with the requirements of this standard. Particular attention is directed to the fuel tank vent requirements and the requirements for all openings to be in or at the topmost surface. Many tanks installed on engines have a bottom fuel supply; this fuel tank is not acceptable for installation in a boat. TO COMPLY Each fuel tank is not integral with any boat structure. There is no fuel tank mounted to a permanently installed engine

IT’S THE LAW - USCG: 183.550 Fuel tanks: Installation. (c) Each fuel tank must not support a deck, bulkhead, or other structural component. A fuel tank is not permitted to be a structural part of a boat to the extent that it provides support for a deck, bulkhead or other boat structure. To determine whether the intent of this regulation is met, the following question must be answered in the affirmative - Is the deck, bulkhead or other structural component properly supported to function as intended with the fuel tank removed? If the answer is no, the tank is providing support that is not acceptable. It is not intended to prohibit incidental contact of a deck, or hatch with a fuel tank, or to prevent the use of protective covers or panels for fuel tanks. The Coast Guard has also accepted fuel tanks specifically designed to be walked or sat upon: Protective mats or panels resting on the tank top to provide a walking surface have also been accepted by the Coast Guard. TO COMPLY The fuel tank does not support a deck, bulkhead, or other structural component. The structure will not collapse if the tank is removed.

 

[Reserector_]

Well, I certainly appreciate you pointing that out, Baylinerchuck. It sounds like you found a good solution. Forums are all about feedback and idea sharing.

Thanks, kcassells. I've been all through that set of regulations, and my installation is in compliance.
What I didn't see was anything that says that an underdeck tank must be in a separate, sealed compartment. I'm not suggesting it's a good or bad idea. Just saying that I could not find a regulation for that in particular.

Keep in mind that my boat was already stripped when I got it. I had nothing to go by, so I searched for official info. I started with the Moeller Tank manufacturer's site and found that they referred to ABYC and USCG, so I dug up those documents.

When it comes to system installation and meeting regulations, I go right to the source and build to code. If I did something wrong, it is because there is a code that did not turn up when I searched, or I misinterpreted a code.
I say all that to try to convince you that I did my homework. That's a big part of why this build is taking so long; I'm having to research EVERYTHING. As a result, I am becoming the world's foremost expert on my particular boat. LOL

 

[kcassells]

All good! As usual.

 

[tpenfield]

You won't find too many boats that have the fuel tank bay 100% sealed off from the rest of the boat. The 2 boats that I've owned have bulkheads fore and aft of the tank, but there are openings for hoses, wiring, and visual inspection.

As posted, the USGC regs are that part of the structure (i.e. a chamber) within the boat cannot also serve as a fuel tank. There has to be a separate tank that is removable.

 

[kcassells]

At the end of the day everyone interprets the regs as they see fit, no harm no foul. Those regs are for mfg's anyway not rehabs. LOL!
Your a good builder so at the end of the day you already know the value of safety and hence dere yago.
Time to move on to the next adventure.

 

[archbuilder]

I am becoming the world's foremost expert on my particular boat. LOL

That just means you are doing a good job!

 

[Baylinerchuck]

Yep I agree....as we go through our own builds, we certainly become experts in those boats. No one will ever know them as intimately as we!

 

[Reserector_]

The remaining foam came off easily with a wire cup wheel in an angle grinder.

I spray-glued 1/2" foam to the back and rough trimmed it. Then came the 1" foam on the inside.

The edges were then trimmed using an electric knife. Next, 1" foam strips were cut and glued to the edges.

 

[Reserector_]

The original vinyl was too brittle to unstitch ans use for patterns, so I have to make my own by temporarily gluing clear plastic to the foam and marking out the panels and seam allowances.
I made patterns for one side and then checked them on the opposite side to maintain symmetry.

I used the side pattern to mark the back seam directly on the foam. Then I created the back panel.

Patterns were also made for the edges and the inside.

The patterns are laid out on the vinyl and traced to make right and left hand parts. Then tie parts are cut out.

Here are the parts for the main cover. I still need to make the top and bottom bolsters, and the bottom and back cushions.

I went ahead and formed the foam for the top bolsters.and went on to make a test seam before calling it a day.

 

[Reserector_]

Quick question... thinking back to the bilge blowers: once the engine is running, will the intake draw enough air to prevent fumes in the engine compartment? Is it safe at that point to shut the blowers off?

The only time that gas fumes develop, barring a leak, is when the engine is off. The fumes eminate from the carburetor. Agree? Disagree?

 

[bruceb58]

Problem with using ink or a marker on foam is that it can bleed thru especially with white vinyl. May take a year though.

Marking on the back side of the vinyl is even worse.

 

[Scott06]

Quick question... thinking back to the bilge blowers: once the engine is running, will the intake draw enough air to prevent fumes in the engine compartment? Is it safe at that point to shut the blowers off?

The only time that gas fumes develop, barring a leak, is when the engine is off. The fumes eminate from the carburetor. Agree? Disagree?

Yes only use prior to start up and theoretically at low speed. You’ll find factory vents will blow air into engine compartment when moving, exhaust will suck off the bottom where vapors heavier than air will accumulate. This is not not only for fuel vapors but engine compartment cooling as well.