belly tank/stringer conflict

[Mark42]

Re: belly tank/stringer conflict

As long as you measured and have the space between where the new stringers will be, the hull looks fine.

Be sure to support the tank properly. Don't just lay it against the hull. A spacer is needed to let water drain freely into the bilge. Check out Lowes and look at the PVC exterior trim. They have some 1x and 2x boards that could be glassed to the hull to support the tank and they won't rot.

 

[chrishayes]

Re: belly tank/stringer conflict

As long as you measured and have the space between where the new stringers will be, the hull looks fine.

Be sure to support the tank properly. Don't just lay it against the hull. A spacer is needed to let water drain freely into the bilge. Check out Lowes and look at the PVC exterior trim. They have some 1x and 2x boards that could be glassed to the hull to support the tank and they won't rot.

I will be using a piece of 3/4" ply laid over the center of the keel so it will be open below it for the tank to sit on. THen the bulkhead in front towards the bow will be cut to fit the v shape of the bottom with a half moon about 3" diameter will be cut out to allow water flow to the open bilge.

Speaking of open bilge, will I still need the air ducting to the tank with it not being enclosed on all 4 sides? the rear of the tank will actually stick out into the bilge for access to the hoses and sender.

What about access hatches? since everything that would need service will be exposed at the bilge why would I need access through the deck? I figure if there is ever a leak it would be time to replace the deck anyhow figuring that the tank should last at least 10 years without leaking. Am I an idiot for not wanting to have access?

 

[chrishayes]

Re: belly tank/stringer conflict

Also, I have some 3/4" rubberish mat on rolls like 4' wide that are used in Hvac applications. I will test it by pouring fuel on it to see if it will eat it. WOuld this be good for providing the tank a soft place to sit within? I would run it below and to the sides of the tank to allow expansion and contraction but still have it supported. Sound good?

 

[Mark42]

Re: belly tank/stringer conflict

I will be using a piece of 3/4" ply laid over the center of the keel so it will be open below it for the tank to sit on. THen the bulkhead in front towards the bow will be cut to fit the v shape of the bottom with a half moon about 3" diameter will be cut out to allow water flow to the open bilge.

The tank diagram shows a 8" wide flat bottom, so I think you are saying that a 8" wide piece of 3/4" ply will be laid in the keel for the tank to rest on. Right? If so, then use pressure treated ply, and make a few knotches along the edge and a few 2" holes down the center for water to drain from this 8" wide piece. Coast Guard has a few words on mounting, see link below.

Speaking of open bilge, will I still need the air ducting to the tank with it not being enclosed on all 4 sides? the rear of the tank will actually stick out into the bilge for access to the hoses and sender.

Probably. You need to read the Coast Guard regulations on gas tanks. It lays out exactly what needs to be done to be legal. Its not hard or expensive, and your installation will be safe and sound. http://www.uscgboating.org/safety/boatbuilder/index.htm

What about access hatches? since everything that would need service will be exposed at the bilge why would I need access through the deck? I figure if there is ever a leak it would be time to replace the deck anyhow figuring that the tank should last at least 10 years without leaking. Am I an idiot for not wanting to have access?

I would build a hatch. Even if its just a removable section of deck held down with stainless steel screws, as long as it can be removed without tearing up the deck, it would be a prudent thing to do. Especially when you're done and you can't find that new Rolex watch you took off while working on the tank.

 

[chrishayes]

Re: belly tank/stringer conflict

The tank diagram shows a 8" wide flat bottom, so I think you are saying that a 8" wide piece of 3/4" ply will be laid in the keel for the tank to rest on. Right? If so, then use pressure treated ply, and make a few knotches along the edge and a few 2" holes down the center for water to drain from this 8" wide piece. Coast Guard has a few words on mounting, see link below.

Well, I guess I could use PT. I have a little that should be dryish(not new). And yes, I would put this ply above the keel. I have read that the tank needs to sit on something soft like rubber or neoprene. THat is why I am thinking of using the HVAC mat stuff that I have. Would I want to drill the same holes through that?



Probably. You need to read the Coast Guard regulations on gas tanks. It lays out exactly what needs to be done to be legal. Its not hard or expensive, and your installation will be safe and sound. http://www.uscgboating.org/safety/boatbuilder/index.htm

will do. Thanks for the link.

I would build a hatch. Even if its just a removable section of deck held down with stainless steel screws, as long as it can be removed without tearing up the deck, it would be a prudent thing to do. Especially when you're done and you can't find that new Rolex watch you took off while working on the tank.

How would I build a section with screws if I am FGing the entire deck along with filling all screw holes w/ epoxy?

UPS man just dropped off my presents from UScomposites! I am getting excited.

 

[chrishayes]

Re: belly tank/stringer conflict

after reading your link, I will go ahead and install a push/pull type natural exhaust system. One clamsell facing forward for supply and one facing backward for the exhaust. I will mount the clams on the rear outside sections of the cap. Do you think this is acceptable? I will be running flex duct under the splashwell to and from the tank rear most compartment and build some type of bracket to hold the intake and exhaust duct above the bilge water level at the tank location.