i'm installing a new waste tank in the bow of my cat. 30. is it best to install it so the top of the tank where my connections will be is flat or could i install it angled against the hull which would put the top on a 35-45* angle.
Orientation of tank
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Do the math!
I think Peggie will agree so I will horn in here. The greater the angle the more volume that you lose. The waste will back up into the inlet/outlet/vent hoses depending where they are on top. Maybe your tank is so large that it is not a concern. Then you also need to place the standpipe(outlet) at the proper "corner" in order to get most of the waste out. Properly positioned this could actually be an advantage to leaning the tank.
I think Peggie will agree so I will horn in here. The greater the angle the more volume that you lose. The waste will back up into the inlet/outlet/vent hoses depending where they are on top. Maybe your tank is so large that it is not a concern. Then you also need to place the standpipe(outlet) at the proper "corner" in order to get most of the waste out. Properly positioned this could actually be an advantage to leaning the tank.
It depends on the angle and the fittings locations
If you have enough clearance above the tank to spec all the fittings on the top of the tank, with a pickup tube inside the tank, it won't matter what the angle is as long as the discharge is is directly above the lowest point in the tank. But if the discharge fitting is at the bottom of the tank, you'd have to put it at the low side. If you've bought an "off the shelf" rectangular tank that already has fittings installed in the so-called "standard" locations (all on one end), your best option would prob'ly be to return it and order a non-rectangular tank (triangular?) that fits your space. Ronco Plastics http://www.ronco-plastics.com is your best source. They make TOP quality thick-walled rotomolded poly tanks for a very reasonable price and have more than 400 shapes and sizes, including over 100 non-rectangular (that include triangular to lie along the hull). And they install fittings in the sizes and locations specified by the customer when they make the tank. And btw...if the tank is to lie along the hull, spec your vent and discharge fitting to be toward the centerline of the boat...to prevent spillage out the vent and waste running back toward the toilet when the boat is heeled. Before tackling this project, you might want to check out the link below.
If you have enough clearance above the tank to spec all the fittings on the top of the tank, with a pickup tube inside the tank, it won't matter what the angle is as long as the discharge is is directly above the lowest point in the tank. But if the discharge fitting is at the bottom of the tank, you'd have to put it at the low side. If you've bought an "off the shelf" rectangular tank that already has fittings installed in the so-called "standard" locations (all on one end), your best option would prob'ly be to return it and order a non-rectangular tank (triangular?) that fits your space. Ronco Plastics http://www.ronco-plastics.com is your best source. They make TOP quality thick-walled rotomolded poly tanks for a very reasonable price and have more than 400 shapes and sizes, including over 100 non-rectangular (that include triangular to lie along the hull). And they install fittings in the sizes and locations specified by the customer when they make the tank. And btw...if the tank is to lie along the hull, spec your vent and discharge fitting to be toward the centerline of the boat...to prevent spillage out the vent and waste running back toward the toilet when the boat is heeled. Before tackling this project, you might want to check out the link below.
i think i'm going to mount it with the
top flat. i think that will work best. thanks for the link. i had purchased your book a few months ago. great information. i'm in rhode island and all of narragansett bay is a no discharge zone so i was thinking of eliminating the y-valve and thru-hull. if my thinking is correct and i'm only going to pump out i need a 1.5" opening in the top of the tank for the pump out, a 1.5" opening in the top to accept the waste from the head, and a 3/4" vent also located in the top. another question. what is the best way to secure the tank in the v-berth. my surveyor had mentioned pouring expandable foam around it.
top flat. i think that will work best. thanks for the link. i had purchased your book a few months ago. great information. i'm in rhode island and all of narragansett bay is a no discharge zone so i was thinking of eliminating the y-valve and thru-hull. if my thinking is correct and i'm only going to pump out i need a 1.5" opening in the top of the tank for the pump out, a 1.5" opening in the top to accept the waste from the head, and a 3/4" vent also located in the top. another question. what is the best way to secure the tank in the v-berth. my surveyor had mentioned pouring expandable foam around it.
Pictures of my install.
See Related Link for some pictures. I used straps rated at, I think, 3000#. At any rate in heavy seas with a nearly full tank it is still in place.
See Related Link for some pictures. I used straps rated at, I think, 3000#. At any rate in heavy seas with a nearly full tank it is still in place.
did you make the
1x12x36" shelf out of marine plywood or something else? is it hard to glass it in. i've never done it before. i was thinking of using 3m 5200. also, where did you get the straps? thanks for the help.
1x12x36" shelf out of marine plywood or something else? is it hard to glass it in. i've never done it before. i was thinking of using 3m 5200. also, where did you get the straps? thanks for the help.
Tank install.
You saw the part about "time and patience" I guess. I use West System epoxy for all of my "glue" and filler projects. The straps, shelf, and stainless screws and bolts I got at Lowes. Using epoxy is not difficult so long as the materials are at hand and you have a plan. Pieces epoxied to the hull have to lie flat without big air gaps. Then sand the hull surface. It does not have to be bare fiberglas, just clean. I used duct tape to hold the pieces in place while the epoxy sets if that will work. The long piece against the bulkhead was screwed in after the wetting. Another way is to cut some old lumber to use as wedges. Anything to hold the piece against the surface while it sets. Once it sets that joint will be forever, much stronger than the wood itself. The shelf piece was just that, one of those things you find at Lowes. Then a couple of coats of paint. There is no weather or water where that tank is going I hope. A P.S. about epoxy. Use something to get the right ratios of hardener to resin. I use the pumps that West System sells. Then watch the air temp. If you work in a hot interior the epoxy could kick before you are ready. Best thing is to read the free West System booklets. P.S.S. I reread your query and need to say that I did not epoxy the shelf, only the supports. The shelf is screwed to those supports. And the straps go under the shelf and are also secured to the bulkhead at the top of tank. Whew!
You saw the part about "time and patience" I guess. I use West System epoxy for all of my "glue" and filler projects. The straps, shelf, and stainless screws and bolts I got at Lowes. Using epoxy is not difficult so long as the materials are at hand and you have a plan. Pieces epoxied to the hull have to lie flat without big air gaps. Then sand the hull surface. It does not have to be bare fiberglas, just clean. I used duct tape to hold the pieces in place while the epoxy sets if that will work. The long piece against the bulkhead was screwed in after the wetting. Another way is to cut some old lumber to use as wedges. Anything to hold the piece against the surface while it sets. Once it sets that joint will be forever, much stronger than the wood itself. The shelf piece was just that, one of those things you find at Lowes. Then a couple of coats of paint. There is no weather or water where that tank is going I hope. A P.S. about epoxy. Use something to get the right ratios of hardener to resin. I use the pumps that West System sells. Then watch the air temp. If you work in a hot interior the epoxy could kick before you are ready. Best thing is to read the free West System booklets. P.S.S. I reread your query and need to say that I did not epoxy the shelf, only the supports. The shelf is screwed to those supports. And the straps go under the shelf and are also secured to the bulkhead at the top of tank. Whew!
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