Cracked holding tank

[Sixbrothers]

I have a new used boat. I discovered a crack in my on top of my holding tank near the 1 1/2" fittings so I'm going to replace the tank. It is about 2/3 full and I tried to have it pumped out with no luck. While the pumpout boat was pumping, I could hear air being sucked into the tank through the crack so I assume the pump out line is clear. Any suggestions on pumping this out? Any suggestions on a replacement tank that is not too costly?

[USCGRET1990]

If I remember right, some of those plastics can now be welded/glued somehow. Might try Googling it.

[deniseO30]

our polyethlene water tank with "scotchweld 8005" from 3m. it really worked too!

we used a dremel to route out the crack and then my son pumped the 8005 mixture in the crack. Don't know if I'd want to fix a holding tank though. stink! ugh!

fair winds!

[JimsCAL]

I would think any type of caulk would temporarily plug the crack so you could get it pumped out. Most of the major marine vendors (West Marine, Defender, etc.) have a selection of Todd plastic tanks. I put one of these in about 10 years ago and it has been fine.

[sailingdog]

If all you need to do is seal the tank long enough to pump it out... just use duct tape to cover the crack, or put a thin sheet of plastic over it and duct tape the edges. This will allow the pumpout fitting to develop enough of a vacuum to empty the tank... it only has to hold through a single pumpout and rinse.

[essman]

I fixed a cracked holding tank a while back with some West System epoxy. Replacement tank not needed. It is still working - and holding.

[Sailormann]

It's well worth the cost of replacing it. If it is cracked in one place - then it's probably not too long before it starts cracking elsewhere...

You really don't want that stuff in the bilges because once the smell permeates the cushions, etc. you're going to end up replacing a lot more than a tank...

[btrayfors]

Ronco Plastics has a very wide selection of tanks. I bought one recently and found them to be very responsive and the tank to be of excellent quality and very reasonably priced.

Ronco Plastics - Rich (714) 259-1385

Ronco Plastics - www.ronco-plastics.com

Bill

[sailingdog]

Just remember to get a tank with thick enough walls to support the weight and bulk of the tank when full. Sewage weighs about 10 lbs. per gallon. Many commercially available tanks are a bit too thin-walled to safely support the weight of the contents... and in this case, that would be really bad.

I believe you will want a roto-molded Polyethylene tank, if you can find one in the right shape for your boat.

[Sixbrothers]

Thanks for all the advice. I pumped the tank out yesterday. I disconnected the hose to a the pump out fitting at the tank and utilizing a contraption I slapped together from duck tape, hose, an old bilge pump, and five gallon buckets. I filled two buckets and emptied them on shore in the marina toilet. It was pretty bad. This stuff came with the boat when I purchased it last November. I am in the process of ordering a new tank that will fit right in.
I can't figure out way I could pump out the tank by hand and the pumpout boat could not. After I pumped it out, I discovered the tank vent somewhat corroded on the outside of the hull. I'm assuming the pumpout boat needed more venting (even with the cracks) to pull the fluid up farther. Or the pump out hose is defective. Or both!

Any thoughts?
Thanks