[danllovi]

Purchased 1998 40 Express with 450hp Cummins July 2014. Love the boat but unfortunately this July the waste holding tank started leaking. Will spare everyone a decription of the odor. Suffice to say the boat was mostly unusable the rest of this season other than for short rides with cabin door closed. It is now in storage while I try to figure out how to replace the tank.
I was surprised to learn that the tank is aluminum which, according to what I have read is very prone to corrode from the product deposited in it. The problem is not the cost of a replacement tank. The problem is the tank is located under the floor of the aft guest bedroom. The aft bedroom is a one piece unit and will have to be sawed out, including parts of the pedastils holding the bed and toilet to remove the tank. It will take a great craftsman to restore it, including the teak and holly floor, so it doesn't look like it was sawed up. The couple of off the cuff estimates I have gotten go well in to 5 figures.
Tried to talk with "customer servicw" at Tiara. Can't talk to them, they only communicate by e-mail. They were less than helpful and wrote they had no idea how to go about the job but"it shouldn't be that difficult". Called local Tiara dealer 3 times for info and a quote and they never got back to me. If anyone has experienced this problem and can share with me I would be most grateful.
  I boat on the Great Lakes out of Cleveland.

[nukey99]

Sorry to hear of this problem, I have the same boat and worry a bit about that tank.  I have found Tiara to be incredibly supportive on my 21 year old vessel.

A thought you might consider.  On an old boat of ours we had a poly water tank that was in a very bad spot and essentially useless.  It would not fit out the access hatch.  I ended up cutting it in pieces, and taking it out bit by bit.  I think you could adopt the same approach on that holding tank, aluminum cuts pretty easily, won't be a fun job, but can be done.

Then you are faced with the how to get a new tank in problem.  You could consider the highest quality diesel fuel bladders you can find and fit one into that spot.  Another option would be to relocate the tank somewhere in the engine room, if you have the overboard discharge capability, you should have hoses running through the engine room.

Good luck with it, and do post solutions followed, as others will probably at some point be in that space.