How to empty a big holding tank... boat in yard...

[Rowglide]

I need to empty a holding tank, approx 8cu-ft. Boat is in a storage yard.
Any suggestions? It is not in a marina so no pump out equipment is available.

[ranger58sb]

Any marinas nearby that use portable pump-out trolleys? If so, maybe rent one?

-Chris

[keith4001r]

Maybe call a Spot-A-Pot company like Jiffy John, etc.?

[peghall]

I'm admittedly reaching a bit with this...but if you have anything to empty it into that's big enough to hold all the tank contents--like maybe a 55 gal barrel?--a macerator pump that can thread into the deck pumpout fitting, and some cheap 1" hose might work. If so, it would most likely be the most affordable solution.

Then the question becomes what to do with the barrel full of sewage. The solution to that needs to include having the barrel on a trailer or the back of a pickup truck if you have access to either one before you fill it. If there's a marina or RV park nearby that's serviced by pumper truck, you might be able to sweet talk the driver into letting you bring there while they're on hand to service the place.

A hare-brained idea...or maybe not?

[Paul L]

Is there a clean out for a sewer run near by? If so, pump it to there.

[darylat8750]

Some companies that provide port-a-potties for events have small trucks that could pump you out

[Pete7]

Originally Posted by darylat8750

Some companies that provide port-a-potties for events have small trucks that could pump you out

Indeed we have a porta loo in the boat yard that a man visits once a week to empty it with a large vacuum cleaner and then wash down the insides etc.

Pete

[Jason Flare]

I have used a wet and dry shop vac to empty a holding tank. It may take several trips to the toilet to empty the contents of the vac but it's manageable.

Wash vacuum well upon completion.

[Calif.Ted]

Originally Posted by Jason Flare

I have used a wet and dry shop vac to empty a holding tank. It may take several trips to the toilet to empty the contents of the vac but it's manageable.

Wash vacuum well upon completion.

Wash ? Soak with gasoline and ignite, maybe.

[thinwater]

Originally Posted by keith4001r

Maybe call a Spot-A-Pot company like Jiffy John, etc.?

In fact, I have used that approach a number of times. Any honey dipper will do it for a reasonable fee, far less than the aggravation is worth, and I'm cheap. They should have the required adapter (1 1/4" NPT to 1 1/2" cam-lock), although it is good to have this on the boat, as it is occasionally needed for pump-out.

Be certain the vent is clear, because when a vac truck gets the tank MT they pull a LOT of air. A LOT at relatively deep vacuum.

[ranger58sb]

Originally Posted by peghall

I'm admittedly reaching a bit with this...but if you have anything to empty it into that's big enough to hold all the tank contents--like maybe a 55 gal barrel?--a macerator pump that can thread into the deck pumpout fitting, and some cheap 1" hose might work. If so, it would most likely be the most affordable solution.

Then the question becomes what to do with the barrel full of sewage. The solution to that needs to include having the barrel on a trailer or the back of a pickup truck if you have access to either one before you fill it. If there's a marina or RV park nearby that's serviced by pumper truck, you might be able to sweet talk the driver into letting you bring there while they're on hand to service the place.

A hare-brained idea...or maybe not?

Building on this...

If the boat has its own macerator pump, normally used to empty the holding tank overboard... maybe there's a way to just use that. Fit some kind of catchment system under the boat's discharge thru-hull, open the seacock, pump it all into the barrel (or whatever)...

?

-Chris

[basssears]

+1 for the blue room service company, I've had it done, quick and easy and not too expensive (I bought a boat, had it hauled immediately for new through hulls and some other plumbing work, found out the holding tank was COMPLETELY full... I knew the seller was full of it, but the boat???)

If your yard has a blue room that's serviced regularly call those guys and maybe they can do it on their regular stop and save you a drive time fee.

-- Bass

[Aquadome]

I can't believe what I'm reading with the suggestions being offered. Call a mobile service and have them send their truck it's fast efficient and environmentally friendly. Who wants to mess with that mess ... how cheap are you?

[jmschmidt]

Commercial septic tank pumping companies might be able to do the job but I don't know about something that small.

[Dymaxion]

OK, if you insist on a DIY....
Get a 5gal water can, they have large mouth screw on cap with valve. The hole is same size as a shop vac hose, plugs in tightly. Find a plastic two part plastic tank fitting with size same as the pump out hose on your tank, or a bit smaller. Drill hole through top of water jug and fit the thru hull in.

Fit pump out hose onto fiting, using duct tape as needed. Plug shop vac into main water jug hole and turn on the vacuum. Watch the crap fill your 5 gal jug quickly, quit before the tank is full. Cap off and go dump it down nearest toilet. Repeat until holding tank is empty. This was bearable for a 12 gal holding tank, Hate to do much more....