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Black tank replacement
Hello! Our 1999 30' Lazy Daze sprung a leak in the black tank. I believe it happened after a cold snap. The crack is not accessible/visible to me when I crawl under. Does anyone know the specs so I can order a new tank and install it? Any recommendations are appreciated. I am in Montana. Thanks.
30' 1999 IB

Re: Black tank replacement
Reply #1
The tanks are custom made for each floorplan, both dimensionally and the locations of the fittings.
The cure for a cracked tank is to remove it and clean well. Find a plastic fabrication shop and have them hot-air weld the crack. The waste tanks are made of ABS plastic and can be melted and fused together.
Broken or damaged fittings can be repaired or a new piece spun-welded in place.

Damaged tanks can many times be temporarily repaired with Eternabond Tape, if the crack is accessible.
If all else fails, new tanks can be manufactured. Better RV repair shops should have access to this service.
All it takes is money.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: Black tank replacement
Reply #2
Thanks, Larry. Is it not possible to buy a new ABS 30 gal tank, of the same size,  that can have holes cut where needed? Or does it need to be custom made?
30' 1999 IB

Re: Black tank replacement
Reply #3
Is it not possible to buy a new ABS 30 gal tank, of the same size,  that can have holes cut where needed? Or does it need to be custom made?

First I’ll like to welcome you to this Neighborhood.  One of the LD parts expert is a gentleman named Todd Miller who used to work at the LD Factory. 

Here’s a link to his contact information. 

[Contact info for Todd Miller (for Lazy Daze parts)]

I think you’ll find him very helpful. 

Re: Black tank replacement
Reply #4
Welcome to the LDOG!   About that black tank:  you wrote.. "can have holes cut where needed? Or does it need to be custom made". Well cutting holes is part of custom made.  There are three holes:  Toilet entry,  vent stack through the roof, and exit for the dump valve.  But in addition, it may be an irregular shape. Mine is a different floorplan than yours, and has an irregular extension for the vent pipe.  Also the mounting brackets grip the tank in certain places to hold it onto the floor of the motorhome.  Those 'gripper' brackets have to be in exact locations they are now, and strong enough to retain a very heavy tank when full.  You wouldn't want to go over some rough rail road tracks and have a full tank fall off!
    So do you have a picture or exact location of your leak?  I know Montana gets cold enough to freeze the contents of the tank. If it had much in it, it could crack the top.  There is a rubber bushing at the top where the vent stack comes out.  I'm not familiar with the plumbing layout for the 30' floorplan.  You would be better served to have your tank repaired, rather than having an entire new tank made.  Much the same techniques for both procedures.    RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Black tank replacement
Reply #5
Thanks Ron. I will get a picture of approximately where the leak is. We could not get our hand in to find/see the leak as it is too tight between the vertical wall between the tires and the tank. The leak started during a cold snap (we didn't have a skirt or heater available).
Thank you very much for the advice. We were thinking it made more sense to replace a 23 year old tank as opposed to repairing it.
30' 1999 IB

Re: Black tank replacement
Reply #6
Hi MamaFree;  So this 'cold snap' was below 25 F for a while and the tank had more than about 1/4 tank?  Black tank contents usually don't freeze too hard. If you have a crack near the top, does it leak all the time,  just when it is near full, or just when the rig is moving?  It still looks like the tank will have to be removed to do anything, inspect or repair.
      I've mostly just seen the drain valves freeze up.  Pouring the pink antifreeze into tanks while using them in winter can protect the valves because that's where the antifreeze settles. And of course if you have power (hookups) you can in the future apply 12vDC or 120VAC electric heat pads to the external tanks.  If the inside of the motorhome is kept warm usually the internal fresh water tank can be kept from freezing.  One person here reported floating chunks of ice in his fresh water tank even though the insides were kept warm.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

 
Re: Black tank replacement
Reply #7
If the crack is on the side of the tank and does not protrude into an edge or corner, it could be repaired by gluing a sheet of ABS plastic over the crack, glued with ABS plumbing cement. Add a could of screws if the sheet slides. It's OK as long as the area surrounding and under the screw is well coated with glue.  Under normal conditions, there is very little pressure on the sides of tanks, if it freezes, the pressure becomes very high.

Whatever way you proceed, the tank must come out. Drain and flush it very well, and remove the toilet along with the toilet floor flange. Many times the toilet flanges are glued and need to be cut to release the tank.
YouTube has many videos on removing and replacing black tanks, you definitely want to watch a few first before proceeding.

The tank has clips that insert into indentations, secured with long bolts and nuts. I usually support the tank by placing a rolling floor jack, with a piece of plywood bolted to the top of the jack, under the tank before unbolting and dropping it.
It's a project full lot of laughs.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze