Holding Tanks - Metal vs Poly

[Howard Kornack]

I am looking at buying a 1995 H430 which has aluminum fresh water and waste tanks. I also want to add a snake-river monitoring system. I am prepared to upgrade all the tanks to'poly' but would appreciate your thoughts on this subject. The snake-river system as you know can accomodate either type of tankage. Thank you.

 

[Peggie Hall/Head Mistress]

ONLY poly for sewage holding

And only thick-walled (at least 3/8") poly. Urine is so corrosive that metal tanks typically start to leak at a seam or fitting within 2-5 years, and turn into a collander within 10. A good quality Ronco or SeaLand holding tank will still be in fine shape after 25 years. However, aluminum is fine for water and fuel holding.

 

[Victor]

Custom poly or inflatable tanks ?

Fortunately (or unfortunately), the only major repair needed when I bought my 1991 Passage 42 was replacing the original aluminum holding tank. Being new to boat maintenance and wanting to get on the water quickly, I ordered the same tank from Hunter, who had it built by the original sub-contractor. The major effort (if you don't count finding a volunteer to lift out the old tank) was in digging out the foam holding in the original tank (an all-day plus job).My reasoning was that I could not get close to the 35 gallon capacity with an off-the shelf rectangular poly tank that would fit into the irregular cavity.Does anyone build custom, irregular shaped poly tanks ?Does anyone have experience with the flexible (bag) type tanks sold at West Marine ?

 

[Dick McKee]

Went through the same thing on our 95 430..

The aft tank looked more like a strainer than a tank. Peggy was a lot of help and sent us a catalogue of tanks. Unfortunately I could find no poly tank that would fit in the space for the aft tank. I even wanted to purchase a custom poly tank, but couldn't find one. We ended up with a new Al tank from Hunter that we are religous about pumping each weekend and flushing several time with fresh water. To replace the aft tank you must also cut the fiberglass at the foot of the sink cabinet to get the tank back in. Its is a mess and a real job. Her catalogue does have a almost perfect replacement for the forward tank, and at the first "smell" of a leak I'm gona replace it. I have the factory drawings for both tanks, and if you want to contact me at McKee119@hotmail.com with a fax # I'll be glad to send you a set.Dick McKeeS/V Constellation