Peggy,

From my understanding, you say that as long as the tank does not leak it can be re-used. The tanks I have are 150g aluminum from 1970, and just sat with who knows what.... lizzards, bees, and who knows what else had gotten into them. I also noticed a bit of black goo come out when i took them out of the boat. I will reuse them but was wondering if you had a better idea for cleaning them. i.e. making a hole on top of tanks, getting a pressure washer and spraying the internals throughly before going through the recommisioning process you've outlined. if making an access hole is an appropriate choice, what would be the accepted method for creating and securing it?

thx, mark

You've misunderstood what I've said, 'cuz there's no way I would ever re-use ANY _meta_l waste holding tank. I have told people who's boats have _meta_l tanks that they can wait to replace 'em UNTIL they start to leak, but there's no way I would ever recommend reinstalling or salvaging a used _meta_l waste tank. The average _meta_l tank, even 316 stainless, typically starts to leak at seam or a fitting within 2-5 years and turns into a collander within about 10 years...any _meta_l tanks that are any older than weren't used to hold sewage longer than the last 10 years.

Sp now that you already have them out of the boat, the smartest thing you can do is replace 'em with good quality plastics tanks...'cuz that black goo you want to clean out of 'em is prob'ly the only thing that's keeping 'em from leaking.

Do it now--and also replace all the hoses--and then you can relaxx and forget about it for as long as you and next 10 people own the boat. But clean and re-install those aluminum tanks, and I'll bet real money that you'll have to replace 'em within two years.

i'm sorry peggy, I was referring to the fresh water tanks... I already trashed the old holding tanks, they were fiberglass... overfilled and sitting for at least 5 years, and the fittings had practically rotted off.

New black water tanks will be on order as soon as I decide the new floorplan for the boat, and where I'm going to mount them. Would you recommend two separate tanks if I have two heads (one forward and one aft)?

Aha... I still wouldn't try to salvage 'em--for two reasons:

1. Their foul condition. Just the memory of the "black goo" alone would be enough to discourage me from ever willingly using water from those tanks for anything but toilet flushing!

2. The lifespan of aluminum water tanks is +/- 20-25 years...that's about how long it takes for the cumulative effect of carrying chlorinated water to eat through 'em...and they're already that old. Once you get 'em clean enough to get a good look at the inside of tank walls, I think you'll find they're pretty badly pitted. Any "sanitizing" chemicals is likely to result in at least one leak.

So bite the bullet and order new ones when you order your waste tanks (yes, you'll need two if the run from either toilet will be much longer than 6'). Ronco Plastics will most likely give you their dealer pricing of 50% off for an order of 3 or 4 tanks, so it won't cost you any more.

Replace all fresh water and sanitation hoses too. Use AVS96 for your 1/5" hoses, Shields or Trident #148 for everything else.

thx for the info, especially on the possible discount for a large order. I will contact them as soon as I'm back to the boat.

Mark